SANS '21-'22, '22-'23, '23-'24: Trauma

What are the (5) 'high risk factors for neurosurgical intervention' to get CTH following CHI?

1. Glasgow Coma Scale score lower than 15 at 2 hours after injury 2. Suspected open or depressed skull fracture 3. Any sign of basal skull fracture * 4. Two or more episodes of vomiting 5. 65 years or older * Signs of basal skull fracture include hemotympanum, racoon eyes, cerebrospinal fluid, otorrhea or rhinorrhea, Battle's sign.

(Bank #1) 23M involved in MVC exhibits sudden neurological decline from initial GCS 15 to 9. He has a new left hemiparesis with a right dilated pupil. Which of the following is the most appropriate next step in mgt of this patient? -Noncontrast head CT -Administration of mannitol -Assessment of respiratory status -Aspirin for evolving stroke -Craniotomy

Assessment of respiratory status. This patient is developing cerebral herniation syndrome with likely expanding intracranial mass lesion. Although mannitol, imaging, and likely eventual surgical intervention are part of the patient's management, the first intervention involves the "ABCs" (airway, breathing, and circulation). This includes obtaining a secure airway and well as hemodynamic stability prior to the next stage of the patient's treatment.

Which of the following is the current "gold standard" for ICP monitoring & mgt? -There is no gold standard for ICP monitoring. -LP -TCD -Fiberoptic intraparenchymal monitor -EVD w/fluid coupled pressure transducer

EVD. The gold standard for ICP monitoring and mgt is the EVD with a fluid coupled pressure transducer. Fiberoptic monitors can also monitor ICP accurately, but do not allow for removal of spinal fluid. Fiberoptic monitors historically suffer from measurement drift and cannot be recalibrated unless replaced. LP allows for CSF drainage & pressure measurements in pts w/ communicating hydrocephalus. It is not accurate in patients with non-communicating hydrocephalus.

35M comes to ED because of 2d hx of severe H/A. The CT scan shown is obtained. The patient is awake, alert, and conversing, but when the patient is returned from the CT scan, he is acutely unresponsive hypertensive, and has bradycardia. Which of the following is the most appropriate next step in mgt? -Have the patient intubated -Administer atropine -Place an EVD -Repeat head CT -Start IV antihypertensive

Have the patient intubated. The patient has likely suffered rupture (in this case likely rerupture) of a cerebral aneurysm. He is experiencing Cushing's triad (unresponsive, hypertensive bradycardic) due to elevated intracranial pressure. The patient is unresponsive and should be intubated. This will also allow for mild hyperventilation to help reduce ICP. The next steps include CT scan and placement of an EVD, and intravenous antihypertensives if blood pressure remains above 160. As the bradycardia is likely caused by the severe hypertension and the patient is not hypotensive, atropine would not typically be administered.

25M with a remote history of complete C6 SCI has onset of severe autonomic dysreflexia after his bladder becomes distended. If untreated, which of the following sequelae of autonomic dysreflexia is most likely to be life-threatening for this patient? -Hypertensive crisis -Piloerection -Profuse diaphoresis and flushing -Tachycardia -Severe headache

Hypertensive crisis Discussion: Acute hypertensive crisis secondary to autonomic dysreflexia (AD), and autonomic dysreflexia itself, in patients with spinal cord injuries, is considered a medical emergency that can lead to seizures, retinal and intracerebral hemorrhages, pulmonary edema, myocardial infarction, and death. These complications are directly caused by severe, sustained, uncontrolled hypertension. The other options are other signs or symptoms of AD, not necessarily life-threatening. References: Reference (1)Allen KJ, Leslie SW. Autonomic Dysreflexia. [Updated 2022 Feb 14]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan- Pubmed Web link https://www.ncbi.nlm.nih.gov/books/NBK482434/ Reference (2) Squair JW, Phillips AA, Harmon M, Krassioukov AV. Emergency management of autonomic dysreflexia with neurologic complications. CMAJ. 2016 Oct 18;188(15):1100-1103. doi: 10.1503/cmaj.151311. Epub 2016 May 24. PMID: 27221275; PMCID: PMC5056874. Pubmed Web link https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5056874/ Reference (3) Bycroft J, Shergill IS, Chung EA, Arya N, Shah PJ. Autonomic dysreflexia: a medical emergency. Postgrad Med J. 2005 Apr;81(954):232-5. doi: 10.1136/pgmj.2004.024463. Erratum in: Postgrad Med J. 2005 Oct;81(960):672. Choong, E A L [corrected to Chung, E A L]. PMID: 15811886; PMCID: PMC1743257. Pubmed Web link https://pubmed.ncbi.nlm.nih.gov/15811886/

Several days s/p endovascular coiling of a rupture aneurysm with Fisher grade 3 SAH, a patient has hypoNa. Which of the following findings would support dx of CSW rather than SIADH? -Hypovolemic state -Increase [UNa] -Low serum urate levels -Low urine output -High UOsm

Hypovolemia is key distinguishing factor in discerning b/w CSW and SIADH secretion. Low urine output is seen in SIADH but not CSW. High UOsm, increase [UNa], and low serum urate levels are seen in both CSW and SIADH.

Which of the following reverses the effects of dabigatran? -Idarucizumab -Protamine -High dose of vitamin K and fresh frozen plasma -Recombinant factor Xa -Platelet transfusion

Idarucizumab Discussion: Idarucizumab (praxbind) is a humanized antibody fragment against dabigatran and adheres to the thrombin-binding site. It has a much higher affinity for dabigatran than thrombin, and the idarucizumab-dabigatran complex is then cleared by the kidneys. Idarucizumab has been shown to rapidly and safely reverse the effects of dabigatran in patients who presented with uncontrolled bleeding or who were about to undergo an urgent procedure in the RE-VERSE AD trial. As idarucizumab is the most specific and fastest reversal agent for dabigatran, it is the preferred option for reversal. Idarucizumab (5 g IV in two divided doses) is recommended for reversal if dabigatran was administered within a period of 3-5 half-lives and there is no evidence of renal failure. If idarucizumab is not available, activated PCC (50 U/kg) is recommended. Idarucizumab can be redosed in patients with ongoing clinically significant bleeding with the addition of hemodialysis if renal failure is present. FFP can be used for warfarin reversal if activated PCC is not available. Platelet transfusions are useful in the reversal of antiplatelet administration. Protamine is used for reversal of unfractionated heparin and low molecular weight heparin. Recombinant factor Xa (andexxa) can be used for the reversal of factor Xa inhibitors such as rivaroxaban, apixaban, and edoxaban. Its use is the subject of ongoing clinical investigation. References: 1. Frontera JA, Lewin JJ 3rd, Rabinstein AA, Aisiku IP, Alexandrov AW, Cook AM, Del Zoppo GJ, Kumar M, Peerschke EI, Stiefel MF, Teitelbaum JS, Wartenberg KE, Zerfoss CL. Guideline for Reversal of Antithrombotics in Intracranial Hemorrhage: Executive Summary. A Statement for Healthcare Professionals From the Neurocritical Care Society and the Society of Critical Care Medicine. Crit Care Med.

20M exhibits a reduction in his ICP when his arterial BP rises. This is an example of which of the following physiologic phenomena? -Hypertensive crisis -Intact cerebral autoregulation -Defective cerebral autoregulation -Cushing's response -Shock

Intact cerebral autoregulation. Discussion: Cerebral autoregulation mediates changes to cerebral blood volume and, in turn, changes in ICP. If autoregulation is intact, decreases in CPP result in vasodilation. This causes increased CBV and increased ICP. Conversely, increases in CPP result in vasoconstriction at the level of the largest arterioles which causes decreased CBV. This leads to a reduction in ICP. Neither Cushing's response, hypertensive crisis or shock are appropriate answers for this phenomenon. References: Rangel-Castilla L, Gasco J, Nauta HJ, et al. Cerebral pressure autoregulation in traumatic brain injury. Neurosurg Focus. 2008 Oct;25(4):E7.Ter Minassian A, Dubé L, Guilleux AM, et al. Changes in intracranial pressure and cerebral autoregulation in patients with severe traumatic brain injury. Crit Care Med. 2002 Jul;30(7):1616-22

(Bank #2) In which of the following types of edema is the extracellular fluid volume decreased? -Ionic (Osmotic) Edema -Amyloid -Vasogenic -Interstitial -Hydrostatic

Ionic (Osmotic) Edema Ionic (Osmotic) edema results due to the development of an ionic gradient leading to movement of water from the extracellular to intracellular spaces. This type of edema is seen in cases of Syndrome of inappropriate antidiuretic hormone (SIADH) or other conditions leading to hyponatremia. Vasogenic, Hydrostatic, Interstitial, and Amyloid-related edema all result in an increase in cerebral extracellular fluid. Cytotoxic edema, or cellular swelling, manifests minutes after acute central nervous system (CNS) injuries. Ionic edema, an extracellular edema that occurs in the presence of an intact blood brain barrier (BBB), forms immediately following cytotoxic edema. Vasogenic edema, an extracellular edema that includes extravasation of plasma proteins, manifests hours after the initial insult.

SIADH secretion is supported by the findings of decreased serum Na level accompanied by which of the following? - High serum Osm - Low urine Osm - Low serum Osm - High serum Na - High TSH

Low serum Osm. SIADH is characterized by lab values consistent with low TSH levels, high urine osmolality and low serum osmolality due to water retention. High Urine Na would be expected in cerebral salt wasting. SIADH is associated with low serum Na.

The mean arterial blood pressure (MAP) at normal resting heart rate is best approximated by which of the following formulas, where SBP is the systolic pressure and DBP the diastolic pressure? -MAP = DBP + 1/4(SBP-DBP) -MAP = SBP - 1/2(DBP) -MAP = DBP + 1/3(SBP-DBP) -MAP = DBP + 1/2(SBP-DBP) -MAP = SBP - 1/3(DBP)

MAP = DBP + 1/3(SBP-DBP). MAP is average arterial pressure throughout 1 cardiac cycle (systole and diastole). MAP is influenced by CO and SVR. Most commonly used formula to estimate MAP is: MAP = DBP + 1/3(SBP-DBP), where SBP = systolic blood pressure and DBP = diastolic blood pressure.

In the management of severe traumatic brain injury, when is hyperventilation therapy indicated? -When brain tissue oxygen levels are low -Never -In conjunction with barbiturate coma -Only as a temporizing measure -Within the first 24h

Only as a temporizing measure. There is no level I evidence regarding the use of hyperventilation. According to the Guidelines for the Management of Severe Traumatic Brain Injury, Fourth Edition, hyperventilation should only be used as a temporizing measure such as en route to operating room or while awaiting other interventions. It should be avoided during the first 24hrs after injury as this can lead to further vasoconstriction and decrease of cerebral blood flow.

A healthy 66M has a type II odontoid fracture. MR imaging shows that the insertion of the transverse ligament is avulsed. Which of the following is the most appropriate management for this odontoid fracture? -External mobilization in halo -External mobilization in collar -Posterior C1-C2 fixation -Anterior odontoid screw fixation with a single screw -Anterior odontoid screw fixation with two screws

Posterior C1-C2 fixation Discussion: Type II odontoid fractures are characterized by a fracture line separating the dens from the body of C2. Obtaining an MRI protocoled to evaluate craniocervical ligaments may be appropriate if initial imaging is concerning for malalignment, joint space widening, angulation, disc injury or clinical concern for high energy injuries. Because the transverse ligament is a key structure in maintaining the structural integrity of the atlantoaxial joint, its damage in combination with the fracture suggest that this is an unstable injury. The most appropriate answer for an unstable C1-2 injury is for instrumentation and fusion. Distractor 1 and 2: anterior odontoid fixation is contraindicated when there is evidence of transverse ligament rupture as it does not sufficiently address instability Distractor 3 and 4: External immobilization may be an appropriate initial conservative measure in linear, non-displaced type II odontoid fractures without ligamentous injury, but not in this case. References: Reference (1)1. Ryken TC, Hadley MN, Aarabi B, Dhall SS, Gelb DE, Hurlbert RJ, Rozzelle CJ, Theodore N, Walters BC. Management of isolated fractures of the axis in adults. Neurosurgery. 2013;72 Suppl 2:132-50.2. Fehlings MG, Arun R, Vaccaro AR, Arnold PM, Chapman JR, Kopjar B. Predictors of treatment outcomes in geriatric patients with odontoid fractures: AOSpine North America multi-centre prospective GOF study. Spine. 2013;38(11):881. Pubmed Web link https://pubmed.ncbi.nlm.nih.gov/23417186/ Reference (2) Joaquim, Andrei F, and Alpesh A Patel. Surgical treatment of Type II odontoid fractures: anterior odontoid screw fixation or posterior cervical instrumented fusion? Neurosurgical focus vol. 38,4 (2015): E11. doi:10.3171/2015.1.FOCUS14781 Pubmed Web link https://pubmed.ncbi.nlm.nih.gov/25828487

Which of the following is the best suture material for wound approximation in a patient with an infected wound? -Vicryl -Prolene -Silk -Monocryl -PDS

Prolene Discussion: The nearest ideal suture for an infected wound, is a monofilament nonabsorbable suture (monofilament nylon). It has low infectivity, results in satisfactory wound tissue strength when used in infected wounds, and retains its strength. Infected, braided sutures of silk, nylon, and polyglycolic acid, even after 70 days, were seen to contain bacteria and polymorphonuclear cells when examined electron microscopically. Absorption of silk and polyglycolic acid and encapsulation of non-absorbable braided nylon was delayed by the presence of infection. Monofilament nylon, in contrast, was unaffected, a fibrous capsule having formed by 10 days even in the infected state. Monocryl, Vicryl, and PDS are all absorbable. Silk and Vicryl are multifilament. Nylon and Prolene and non-absorbable monofilament. References: Bucknall TE, Teare L, Ellis H. The choice of a suture to close abdominal incisions. Eur Surg Res. 1983;15(2):59-66. doi: 10.1159/000128334. PMID: 6303791. Dennis C, Sethu S, Nayak S, Mohan L, Morsi YY, Manivasagam G. Suture materials - Current and emerging trends. J Biomed Mater Res A. 2016 Jun;104(6):1544-59. doi: 10.1002/jbm.a.35683. Epub 2016 Apr 4. PMID: 26860644.

A previously healthy 26M is involved in a MVC, resulting in severe head trauma that is c/b an anoxic brain injury during extrication from the vehicle. It is determined that there is no medical or surgical intervention that can help this patient. The patient's family would like to move forward with organ donation. Which of the following would prevent organ donation at this time? -Unable to confirm organ donor status on driver's license -Sepsis -Patient is not brain dead -Professional tattoos -Alcoholism

Sepsis. There are surprisingly few absolute contra-indications to organ donation, but sepsis is one of them. Alcoholism and (non-prison) tattoos do not typically exclude organ donation. Families can choose organ donation for family members who do not have their donor status explicitly stated on their license or proxy documents. Donation after cardiac death (DCD) allows for donation in patients who are not brain dead.

When treating a patient with acute symptomatic hyponatremia with hypertonic saline, the maximum correction of plasma sodium levels in the first 24 hours is - 1-4 mEq/L - No current guidelines - 4-8 mEq/L - >15 mEq/L - 12-15 mEq/L

4-8 mEq/L Discussion: Sodium correction is based on the acuity of hyponatremia and the severity of symptoms. In acute symptomatic hyponatremia, a correction of 4-6 mEq/L (up to 8mEq/L) is safe and can be achieved within a few hours, with maintenance of stable sodium levels for up to 24 hours. A more rapid correction can lead to osmotic demyelination syndrome with neurologic sequelae thereof. References: Sterns RH, Nigwekar SU, Hix JK. The treatment of hyponatremia. Semin Nephrol. 2009 May;29(3):282-99; Verbalis JG, Goldsmith SR, Greenberg A, Korzelius C, Schrier RW, Sterns RH, Thompson CJ. Diagnosis, evaluation, and treatment of hyponatremia: expert panel recommendations. Am J Med. 2013 Oct;126(10 Suppl 1):S1-42.

Which of the following age groups is at greatest risk for TBI? - >=65 - 55-64 - 25-34 - 20-24 - 45-54

>=65. Discussion: Children aged 0 to 4 years, older adolescents aged 15 to 19 years, and adults aged 65 years and older are most likely to sustain a traumatic brain injury. References: 1. U.S. Centers for Disease Control. Incidence Rates of Hospitalization Related to Traumatic Brain Injury --- 12 States, 2002. 2. https://www.aans.org/Patients/Neurosurgical-Conditions-and-Treatments/Traumatic-Brain-Injury

Which of the following complications has been linked to aggressive use of pressors and IVF to maintain elevated CBF in patients with severe TBI? -Worsening neurological outcome -ARDS -Refractory elevated ICP -AKI -Progression of intracranial hematoma

ARDS. Robertson et al reported a clinical trial comparing intracranial pressure (ICP) directed therapy with cerebral perfusion pressure (CPP) directed therapy and found that artificially elevating the CPP > 70mmHg led to a five-fold increase in the incidence of acute respiratory distress syndrome. The other variables, although theoretically possible, were not shown to be true in this trial.

60M is admitted to the ICU after sustaining an inoperative closed head injury in a MVC. Lab studies show an increased serum creatinine level, muddy brown casts in urine sediment, and an increased fractional excretion of sodium. Which of the following is the most likely diagnosis? -Dehydration -Acute tubular necrosis (ATN) -Acute bladder obstruction -Kidney laceration -Cerebral salt wasting

ATN. Muddy brown epithelial casts in the urine are pathognomonic for acute tubular necrosis (ATN). The casts form when either ischemia or toxins cause damage to the epithelial cells of the renal tubules causing them to slough off and form casts in the renal tubule. The casts are then eventually excreted into the urine. ATN can be caused by ischemia (usually due to shock) or toxins.The fractional excretion of sodium is the percentage of sodium that is excreted into the urine during renal filtration. Intrinsic kidney failure such as ATN will result in an increased FENa as sodium recovery in the renal tubule is impaired. Extrinsic causes of renal failure such as dehydration or acute bladder obstruction will typically have a low FENa, at least in the acute phase. A kidney laceration would cause blood in the urine. Cerebral salt wasting can be caused by a closed head injury and may be associated with an elevated FENa. The cause of CSW is not well understood but has been attributed to perturbations in the sympathetic nervous system or the release of BNP. It is not, however, a kidney injury in itself and is not associated with casts in the urine unless there is secondary injury to the kidney due to severe hypovolemia.

Which of the following conditions is most likely to require that a patient's airway be secured via emergency cricothyroidotomy because of an inability to perform endotracheal intubation? -Thoracic empyema -Septic shock -Diaphragmatic hernia -Anaphylaxis -Flail chest

Anaphylaxis Discussion: Management of anaphylaxis involves rapid assessment of a patient's airway with emergent intubation being performed if stridor or respiratory distress occurs due to upper airway compromise. With anaphylaxis, significant edema of the tongue and oropharyngeal tissues can occur. Early presence of upper airway edema can represent rapidly developing airway compromise. In some cases, emergent cricothyroidotomy may be required if severe upper airway edema prevents access to the glottic aperture, even while using a video laryngoscope. Unless intubation occurs early when there is minimal disruption of the upper airway anatomy, intubation should ideally be performed using an awake fiberoptic approach. References: 1. Soar J, Pumphrey R, Cant A, Clarke S, Corbett A, Dawson P, Ewan P, Foëx B, Gabbott D, Griffiths M, Hall J, Harper N, Jewkes F, Maconochie I, Mitchell S, Nasser S, Nolan J, Rylance G, Sheikh A, Unsworth DJ, Warrell D; Working Group of the Resuscitation Council (UK). Emergency treatment of anaphylactic reactions--guidelines for healthcare providers. Resuscitation. 2008 May;77(2):157-69. doi: 10.1016/j.resuscitation.2008.02.001. Epub 2008 Mar 20. PMID: 18358585 2. Brown SG, Mullins RJ, Gold MS. Anaphylaxis: diagnosis and management. Med J Aust. 2006 Sep 4;185(5):283-9. doi: 10.5694/j.1326-5377.2006.tb00619.x. Erratum in: Med J Aust. 2006 Oct 2;185(7):400. Dosage error in article text. PMID: 16948628 3. Simons FE, Ardusso LR, Bilò MB, El-Gamal YM, Ledford DK, Ring J, Sanchez-Borges M, Senna GE, Sheikh A, Thong BY; World Allergy Organization. World Allergy Organization anaphylaxis guidelines: summary. J Allergy Clin Immunol. 2011 Mar;127(3):587-93.e1-22. doi: 10.1016/j.jaci.2011.01.038. PMID: 21377030.

73F with paroxysmal atrial fibrillation is receiving rivaroxaban for ischemic stroke prophylaxis. She sustains an intraparenchymal hemorrhage. Which of the following is the most appropriate pharmacotherapy for reversing this patient's anticoagulation? -FFP -Tranexamic acid -Idarucizumab -Vitamin K -Andexanet alfa

Andexanet alfa Discussion: Rivaraoxaban and Apixaban are factor Xa inhibitors used in atrial fibrillation to prevent thromboembolic events. Andexanet alfa is a recombinant modified human factor Xa protein that binds directly to free-floating factor Xa inhibitors with high affinity, sequestering them, and thus reducing the free plasma concentration of these agents neutralizing their anticoagulant effect. Tranexamic acid is an anti-fibrinlolytic agent with no mechanism to neutralize the effect of factor Xa inhibitors. Vitamin K and FFP are synergistically used to replenish and restore hepatically synthesized clotting factors inhibited by warfarin. Idarucizamab is a humanized monoclonal antibody fragment that binds to dabigatran with higher affinity, neutralizing its anticoagulant effect. References: Connolly SJ, Crowther M, Eikelbloom JW, et al. Full study report of andexanet alfa for bleeding associated with factor Xa inhibitors. N Engl J Med. 2019;380(14):1326-1335 Christos S, Naples R. Anticoagulation reversal and treatment strategies in major bleeding: update 2016. West J Emerg Med 2016;17(3):264-270 Frontera JA, Lewin JJ 3rd, Rabinstein AA, Aisiku IP, Alexandrov AW, Cook AM, del Zoppo GJ, Kumar MA, Peerschke EI, Stiefel MF, Teitelbaum JS, Wartenberg KE, Zerfoss CL. Guideline for Reversal of Antithrombotics in Intracranial Hemorrhage: A Statement for Healthcare Professionals from the Neurocritical Care Society and Society of Critical Care Medicine. Neurocrit Care. 2016 Feb;24(1):6-46 Greenberg SM, Ziai WC, Cordonnier C, Dowlatshahi D, Francis B, Goldstein JN, Hemphill JC 3rd, Johnson R, Keigher KM, Mack WJ, Mocco J, Newton EJ, Ruff IM, Sansing LH, Schulman S, Selim MH, Sheth KN, Sprigg N, Sunnerhagen KS; American Heart Association/American Stroke Association. 2022 Guideline for the Management of Patients With Spon

A 25M is brought to the ED after sustaining multiple severe injuries in a motor vehicle collision. Which of the following best predicts the need for massive transfusion to prevent lethal exsanguination? -SBP < 110 mmHg -Open femur fracture -Pulse pressure < 20 mmHg -Heart rate > 120/min -GCS < 9

Heart rate > 120/min Discussion: The "ABC score" consists of four dichotomous components that are available at the bedside of the acutely injured patient early in the assessment phase. The presence of anyone component contributes 1 point to the total score. Scores range from 0 to 4. The parameters include: 1) penetrating mechanism, 2) emergency department systolic blood pressure less than 90 mmHg, 3) emergency department heart rate > 120 beats per minute, and 4) positive FAST. A score of 2 or greater was used to define "predicted to receive MT." The only one of these four factors the patient has is a heart rate over 120. Multiple scales use a cut-off of SBP of 90 (not 110). References: Cotton BA, Dossett LA, Haut ER, Shafi S, Nunez TC, Au BK, et al. Multicenter validation of a simplified score to predict massive transfusion in trauma. J Trauma. 2010 Jul;69 Suppl 1:S33-9. Ogura T, Nakamura Y, Nakano M, Izawa Y, Nakamura M, Fujizuka K, Suzukawa M, Lefor AT. Predicting the need for massive transfusion in trauma patients: the Traumatic Bleeding Severity Score. J Trauma Acute Care Surg. 2014 May;76(5):1243-50. doi: 10.1097/TA.0000000000000200. PMID: 24747455.

34F with headache and confusion. Non-contrast (Figure 1) and contrast-enhanced (Figure 2) CT scans are shown. Neurological examination is stable over the first few hours and vital signs are within normal ranges. Which of the following is the most appropriate immediate therapeutic intervention? -Cerebral angiography -Aspirin -Hemicraniectomy -Heparin infusion -Steroids

Heparin infusion Discussion: The axial nonenhanced CT images shows abnormal hyperattenuation consistent with Cerebral Venous Thrombosis in the superior sagittal sinus. Axial contrast-enhanced CT image shows the empty delta sign. The empty delta sign consists of a triangular area of contrast enhancement that surrounds a hypoattenuating area and represents the thrombus; although this sign classically is found in the superior sagittal sinus, a similar sign can be seen on sagittal and coronal images of the transverse sinus. Anticoagulation is the first line, mainstay treatment of cerebral venous thrombosis, even with the presence of acute hemorrhage. Neither steroids nor aspirin have anticoagulant properties. Cerebral angiography with or without interventions is not indicated at this time and might be considered in cases refractory to medical management on a case-by-case basis. There is no evidence to support hemicraniectomy in this scenario given clinical stabiity and lack of radiological evidence to warrant surgery. References: Connolly SJ, Crowther M, Eikelbloom JW, et al. Full study report of andexanet alfa for bleeding associated with factor Xa inhibitors. N Engl J Med. 2019;380(14):1326-1335 Christos S, Naples R. Anticoagulation reversal and treatment strategies in major bleeding: update 2016. West J Emerg Med 2016;17(3):264-270 Frontera JA, Lewin JJ 3rd, Rabinstein AA, Aisiku IP, Alexandrov AW, Cook AM, del Zoppo GJ, Kumar MA, Peerschke EI, Stiefel MF, Teitelbaum JS, Wartenberg KE, Zerfoss CL. Guideline for Reversal of Antithrombotics in Intracranial Hemorrhage: A Statement for Healthcare Professionals from the Neurocritical Care Society and Society of Critical Care Medicine. Neurocrit Care. 2016 Feb;24(1):6-46 Greenberg SM, Ziai WC, Cordonnier C, Dowlatshahi D, Francis B, Goldstein JN, Hemphill JC 3rd, Johnson R

Which of the following reflects the change in energy requirements and nutritional substrate that would consequently account for >15% of a patient's daily caloric intake in the first two weeks after a head injury? -Increased carbohydrate requirement to maintain euglycemia -Hypometabolism and decreased protein metabolism requiring less protein supplementation -Increased fatty acid oxidation requiring increased saturated fatty acid supplementation -Hypermetabolism and increased nitrogen excretion

Hypermetabolism and increased nitrogen excretion Discussion: It has been known for decades that patients with traumatic brain injury (TBI) have a hypermetabolic state with hypercatabolism of whole-body protein leading to a highly negative nitrogen balance, similar to patients with severe polytrauma or extensive burns. The complex neuro-endocrine-immune response to TBI triggers enhanced gluconeogenesis secondary to skeletal muscle protein hypercatabolism through activation of the ubiquitin-proteasome system. This exacerbated whole body protein catabolism for endogenous calories can be attenuated by the provision of high levels of dietary protein. However, increasing protein administration in order to block nitrogen wasting after TBI may result in further elevation of protein catabolism so that only 50% of the nitrogen supply is retained at high levels of protein intake. Current guidelines recommend administration of 1.5 to 2.0 g/kg/day of protein accompained by at least 50% of energy needs up to 25-30 kcal/kg/day. Short term permissive underfeeding while supplying greater levels of protein intake is thought to improve the preservation of fat-free mass and improve synthetic protein rates. References: 1. Kurtz and Rocha, Nutrition Therapy, Glucose Control, and Brain Metabolism in Traumatic Brain Injury: A Multimodal Monitoring Approach.Frontiers in Neuroscience, March 2020, volume 14, article 190 2. van Zanten ARH, Petit L, De Waele J, Kieft H, de Wilde J, van Horssen P, Klebach M, Hofman Z. Very high intact-protein formula successfully provides protein intake according to nutritional recommendations in overweight critically ill patients: a double-blind randomized trial. Crit Care. 2018 Jun 12;22(1):156. doi: 10.1186/s13054-018-2070-5. PMID: 29895309; PMCID: PMC5998555. 3. McClave SA, Taylor BE, Martindale RG, Warren MM,

Pseudohyponatremia is most likely in patients with which of the following conditions? -Hypertriglyceridemia -Diabetes insipidus -Carbamazepine use -SSRI use -Septic shock

Hypertriglyceridemia. Discussion: PseudohypoNa consists of a state where there is a reduction in the % of water in plasma relative to sodium, such as a state of hypertriglyceridemia, where there is a lower sodium concentration as a result of high triglycerides that reduces the percentage of water, and thus falsely lowering the concentration of sodium. SSRI and carbamazepine result in hyponatremia due to SIADH and excessive water retention due to elevated ADH secretion. Diabetes insipidus results in hypernatremia. References: Wang Y, Attar BM, Abu Omar Y, Agrawal R, Demetria MV. Pseudohyponatremia in Hypertriglyceridemia-Induced Acute Pancreatitis: A Tool for Diagnosis Rather Than Merely a Laboratory Error? Pancreas. 2019 Jan;48(1):126-130; Adashek ML, Clark BW, Sperati CJ, Massey CJ. The Hyperlipidemia Effect: Pseudohyponatremia in Pancreatic Cancer. Am J Med. 2017 Dec;130(12):1372-1375.

A decrease in which of the following explains the mechanism by which hyperventilation lowers ICP? -Oxygen saturation -PaCO2 -Mean arterial pressure -PEEP -Arteriolar smooth muscle tone

Hyperventilation causes decreased PaCO2 which incites constriction of arteriolar smooth muscles (increased tone). This results in decreased cerebral blood flow and decreased cerebral blood volume which leads to a decrement in ICP.

17M who sustained a severe brain injury in a MVA is becoming progressively hypotensive. A Swan-Ganz catheter shows a cardiac output of 4.0L/min, a pulmonary capillary wedge pressure of 4.0 mmHg, and a systemic vascular resistance of 1400 dynes/sec/cm5. Which of the following is the most likely diagnosis?

Hypovolemia Discussion: Normal range for SVR is 800-1200 synes-s/cm5. Wedge pressure is normally 6-18 mm Hg. Cardiac output is normally 4-8 L/min. This young patient with a traumatic brain injury (TBI) is becoming progressively hypotensive with a cardiac output that is on the lower end or norma, a low wedge pressure, and an increased SVR. This set of monitoring values is most consistent with hypovolemia, which commonly occurs after polytrauma and TBI. Physical examination findings are also likely to demonstrate cool limbs, dry mucus membranes, and flat neck veins. Patients with distributive shock will also have low wedge pressures but typically have decreased SVR. Patients with cardiogenic shock have increased wedge pressure as well as increased SVR. Obstructive shock can be due to a variety of conditions such as pulmonary embolism, acute or worsening pulmoanry hypertension, constrictive pericarditis, restrictive cardiomyopathy, or tension pneumothorax. Obstructive shock can mirror cardiogenic shock on clinical examination with the absence of pulmonary rales. Patients with cardiac tamponade have elevated wedge pressures and often demonstrate tachycardia initially followed by the development of pulsus paradoxus and refractory hypotension. References: 1. Simmons J, Ventetuolo CE. Cardiopulmonary monitoring of shock. Curr Opin Crit Care. 2017 Jun;23(3):223-231. doi: 10.1097/MCC.0000000000000407. PMID: 28398907; PMCID: PMC5678958. 2. Singer M, Deutschman CS, Seymour CW, Shankar-Hari M, Annane D, Bauer M, Bellomo R, Bernard GR, Chiche JD, Coopersmith CM, Hotchkiss RS, Levy MM, Marshall JC, Martin GS, Opal SM, Rubenfeld GD, van der Poll T, Vincent JL, Angus DC. The Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3). JAMA. 2016 Feb 23;315(8):801-10. doi: 10.1001/jama.2016.0287. PMID: 26903338; P

25M is brought to the ED immediately after sustaining injuries in a MVC. His BP is 70/40 mmHg and GCS is 6. He is endotracheally intubated with bilateral breath sounds. His blood pressure increases only transiently in response to IV fluid boluses. Which of the following is the most likely cause of this patient's persistent hypotension? -Hypovolemic shock -Obstructive shock -Distributive shock -Septic shock -Cardiogenic shock

Hypovolemic shock Discussion: In the setting of polytrauma, the most likely cause of acute shock state with minimal/transient response to IV fluids is hypovolemic shock secondary to hemorrhage, causing a decrease in intravascular volume -> decreased stroke volume -> decreased cardiac output; the administration of IV fluid bolus will transiently increase intravascular volume which will, in turn, cause an increase in stroke volume followed by an increase in cardiac output, but given the likely active exsanguination, this response is only transient. Obstructive shock, which can be caused by tension pneumothorax or cardiac tamponade, could be a possible cause, but given bilateral breath sounds after intubation and the transient improvement in blood pressure after IV fluids would be less likely for obstructive shock to be the cause. Cardiogenic shock, usually caused by arrhythmias, acute myocardial infarction among others, would also be less likely. Distributive shock, which includes septic shock, would be very unlikely in this setting. References: Reference (1)Kislitsina ON, Rich JD, Wilcox JE, Pham DT, Churyla A, Vorovich EB, Ghafourian K, Yancy CW. Shock - Classification and Pathophysiological Principles of Therapeutics. Curr Cardiol Rev. 2019;15(2):102-113. doi: 10.2174/1573403X15666181212125024. PMID: 30543176 Pubmed Web link https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6520577/ Reference (2) Fecher A, Stimpson A, Ferrigno L, Pohlman TH. The Pathophysiology and Management of Hemorrhagic Shock in the Polytrauma Patient. J Clin Med. 2021 Oct 19;10(20):4793. doi: 10.3390/jcm10204793. PMID: 34682916 Pubmed Web link https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8541346/ Reference (3) Taghavi S, Askari R. Hypovolemic Shock. [Updated 2022 May 1]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 J

If a patient on dabigatran presents with a post-traumatic aSDH requiring surgery, which of the following drugs can be used to reverse the anticoagulation of dabigatran? -Idarucizumab -PCC -Vit K -TXA -FFP

Idarucizumab. Many agents have been administered for the reversal of dabigatran, but the only effective medication is idarucizumab. This is a monoclonal Ab fragment specifically designed to reverse the anticoagulation effects. The other medications may have some effect but are not the appropriate therapy in an operative intracranial mass lesion.

25M is brought to the emergency department. He is bleeding profusely from extensive lower facial fractures. Pulse is 84/min, blood pressure is 110/65 mmHg, and oxygen saturation is 85%. Which of the following interventions is the most appropriate initial step in management? -Transfusion of packed red blood cells -Application of laryngeal mask airway -Anterior tibial intraosseous cannulation -Administration of prothrombin complex concentrate -Performance of cricothyroidotomy

Performance of cricothyroidotomy Discussion: In the setting of trauma, the order of airway, breathing, and circulation should always be remembered. Mandibular fractures, facial swelling, and bleeding lead to difficulty with jaw thrust and difficulty maintaining a seal during bag-mask ventilation and call for an early subglottic airway. The provider should presume that preoxygenation with mask ventilation in patients with facial trauma may be difficult and that reoxygenation during Rapid Sequence Intubation (RSI) if the first attempt is unsuccessful, may be difficult or impossible. Distortion of facial structures may make obtaining a seal with a bag valve mask device (BVM) device difficult. Patients may poorly tolerate positive pressure ventilation, as disruption of tissues may result in worsening bleeding and, in cases of associated lower airway trauma, significant subcutaneous emphysema. Practitioners must proceed with the assumption that structural collapse of the airway may occur during an RSI. The choice of approach is based on the patient's ability to maintain a patent airway and oxygenation status. For a "have no time" scenario (obstructing and hypoxemic), the primary approach may require the performance of cricothyroidotomy facilitated by a dissociative ketamine dosing. Alternatively, a "double set-up" may be used: Rapid Sequence Intubation with a single attempt at oral intubation followed immediately by front of neck airway rescue. References: Kovacs G, Sowers N. Airway Management in Trauma. Emerg Med Clin North Am. 2018 Feb;36(1):61-84. Langeron O, Birenbaum A, Amour J. Airway management in trauma. Minerva Anestesiol. 2009 May;75(5):307-11. PMID: 19412149.

Which of the following opioids is most appropriate to enable neurological assessments because of its rapid metabolism? -Propofol -Midazolam -Pentobarbital -Remifentanil -Fentanyl

Remifentanil Discussion: Of the given choices, remifentanil has the faster onset of metabolism, followed by propofol, fentanyl, midazolam and pentoparbital. As a result, it is s most beneficial for a rapid assessement of neurological examinations. However, its availability and cost may be limited in some institutions. The main advantage of remifentanil is its extremely brief half-life. The elimination half-life is 3 to 6 minutes and is independent of dose and duration. Remifentanil is degraded by nonspecific plasma and tissue esterases and metabolism is not affected by butyrylcholinesterase deficiency. Propofol is bi-phasic, with its initial half-life being relatively quick, around 40 minutes, and its terminal half-life usually being 4 to 7 hours. Context-sensitive half-time may be up to 1 to 3 days after a 10-day infusion. Fentanyl's onset of action is less than 60 seconds with a half-life of 90 minures and duration of action near 30-60 minutes. Its peak effect is 2-5 minutes. The α-half-life (distribution and redistribution) of midazolam has been recorded as 4 to 18 minutes. The β-half-life (metabolism and excretion) is 1.7 to 2.4 hours. By contrast, diazepam's β-half-life is 31.3 hours. The half-life of pentobarbital is approximately 20 hours but may be extended at higher levels. References: Fodale V, Schifilliti D, Praticò C, et al. Remifentanil and the brain. Acta Anaesthesiol Scand. 2008 Mar; 52(3):319-26 Opdenakker, O. , Vanstraelen, A. , De Sloovere, V. & Meyfroidt, G. (2019). Sedatives in neurocritical care: an update on pharmacological agents and modes of sedation. Current Opinion in Critical Care, 25 (2), 97-104 Karabinis A, Mandragos K, Stergiopoulos S, et al. Safety and efficacy of analgesia-based sedation with remifentanil versus standard hypnotic-based regimens in intensive care unit patients

In which of the following situations are corticosteroids indicated for the treatment of sepsis? -SBP < 100 refractory to IV fluids and vasopressor administration -SBP > 100 on multiple abx -SBP > 100 with IV fluids - SBP < 100 with known bacterial infxn - SBP > 100 requiring low dose vasopressors

SBP < 100 refractory to IV fluids and vasopressor administration. Corticosteroid use in septic shock is indicated as adjunctive therapy for hemodynamic support for patients needing escalating doses of vasopressors after optimal fluid resuscitation. However, it is not a 1st line treatment of HoTN in septic shock. In adults with septic shock treated with low dose corticosteroids, short- and longer-term mortality are unaffected, adverse events increase, but duration of shock, mechanical ventilation and ICU stay are reduced. The etiology of the septic shock and concurrent use of abx are variables that have no relevance to the concurrent use of corticosteroids.

One day after undergoing anterior cervical decompression and fusion as treatment for a severe cervical injury, a 45-year-old man develops acute upper gastrointestinal bleeding. There is no history of smoking or alcoholism. Which of the following is the most likely cause of this patient's condition? -Stress-related mucosal damage -Acute colonic pseudo-obstruction -Spontaneous bowel perforation secondary to post-operative ileus -Spontaneous esophageal rupture -Esophageal perforation during surgery

Stress-related mucosal damage Discussion: Although uncommon, the most likely cause of acute upper gastrointestinal (GI) bleeding in the post-operative setting is gastritis secondary to stress-related mucosal damage in the upper GI tract, causing bleeding of gastric and/or duodenal ulcers within the first 48 hours post-op. Other causes can include exacerbation of established peptic ulcer disease or, less likely, vascular-enteric communications resulting from inflammatory or infectious processes, which usually present > 48hrs post-op. Acute colonic pseudo-obstruction and spontaneous bowel perforation secondary to post-operative ileus would be extremely rare causes of GI bleeding in the first 24hrs after surgery and would not cause upper GI bleeding. References: Reference (1)Jones S, May AK. Postoperative gastrointestinal hemorrhage. Surg Clin North Am. 2012 Apr;92(2):235-42, viii. doi: 10.1016/j.suc.2012.01.002. Epub 2012 Feb 1. PMID: 22414410. Pubmed Web link https://pubmed.ncbi.nlm.nih.gov/22414410/ Reference (2) Pollard TR, Schwesinger WH, Page CP, Schauer PR, Sirinek KR. Upper gastrointestinal bleeding following major surgical procedures: prevalence, etiology, and outcome. J Surg Res. 1996 Jul 15;64(1):75-8. doi: 10.1006/jsre.1996.0309. PMID: 8806477. Pubmed Web link https://pubmed.ncbi.nlm.nih.gov/8806477/ Reference (3) Matsumura JS, Prystowsky JB, Bresticker MA, Meyer PR Jr, Joehl RJ, Nahrwold DL. Gastrointestinal tract complications after acute spine injury. Arch Surg. 1995 Jul;130(7):751-3. doi: 10.1001/archsurg.1995.01430070073014. PMID: 7611864. Pubmed Web link https://pubmed.ncbi.nlm.nih.gov/7611864/

24F is evaluated because of a 6-month history of irregular menses and headache. Visual field testing shows bitemporal hemianopia. MR images are shown. Serum prolactin level is 80 ng/mL. Which of the following is the most appropriate treatment for this patient? -Start cabergoline and repeat pituitary MRI in 6 months. -Refer patient for stereotactic radiosurgery. -Refer patient to endocrinology and gynecology for further evaluation. -Surgical resection of pituitary adenoma. -Start bromocriptine and repeat pituitary MRI in 12 months

Surgical resection of pituitary adenoma Discussion: The patient presents with a history of headaches, irregular menses, which are concerning for pituitary dysfunction, signs of chiasmal compression given bitemporal hemianopsia, and elevated serum prolactin, which are signs of pituitary adenoma. MRI findings are compatible with a pituitary macroadenoma, given that size is ≥ 1cm. Surgical resection is the recommended treatment for patients with macroadenomas exhibiting visual field deficits secondary to the macroadenoma compressing the optic nerve or chiasm and in patients with pituitary apoplexy with visual disturbances. The goal of surgical resection is to provide symptom relief, preservation of surrounding structures, and prevention of further deterioration of vision and pituitary function, as well as, attempting to reverse any already present symptoms. Cabergoline and Bromocriptine are dopaminergic agonists used as primary therapy for patients with hyperprolactinemia and prolactinomas with no signs of optic nerve or chiasmatic compression. Stereotactic radiosurgery is usually considered when the initial interventions fail or when there is recurrence of disease. References: Reference (1)Esposito D, Olsson DS, Ragnarsson O, Buchfelder M, Skoglund T, Johannsson G. Non-functioning pituitary adenomas: indications for pituitary surgery and post-surgical management. Pituitary. 2019 Aug;22(4):422-434. Pubmed Web link https://pubmed.ncbi.nlm.nih.gov/31011999/ Reference (2) Casanueva FF, Molitch ME, Schlechte JA, Abs R, Bonert V, Bronstein MD, Brue T, Cappabianca P, Colao A, Fahlbusch R, Fideleff H, Hadani M, Kelly P, Kleinberg D, Laws E, Marek J, Scanlon M, Sobrinho LG, Wass JA, Giustina A. Guidelines of the Pituitary Society for the diagnosis and management of prolactinomas. Clin Endocrinol (Oxf). 2006 Aug;65(2):265-73.

49M is brought to ED s/p MVC. Physical exam demonstrates no verbal response, eye opening only to painful stimuli, and localizing in response to noxious stimuli. Which of the following is the most likely Glasgow Coma Scale score in this patient? -7 -10 -6 -8 -11

The Glasgow Coma Scale (GCS) score is made up of three components (Eye, Verbal, and Motor) for a total score of 3 to 15. This particular patient has a score of E2 (eyes open to pain), V1 (no verbal response), and M5 (localization) for a total score of 8.

32M with severe closed head injury develops a sodium level of 123 mEg/L and becomes more obtunded. Serum osmolality is 275 mOsmol/kg H2O and he is euvolemic. Which of the following is the most specific treatment for the suspected diagnosis? -Urea -Loop diuretics -Vaptans -Hypertonic saline -Demeclocycline

Vaptans Discussion: All of the options are treatments for Syndrome of inappropriate antidiuretic hormone secretion (SIADH), which is the likely diagnosis here, however vaptans are the most specific treatment options available for SIADH. Vaptans are vasopressin antagonists that inhibit its effects. In SIADH, vasopressin is secreted inappropriately in a plasma volume independent fashion. Selective vasopressin V2-receptor antagonists were shown to be effective in raising sodium levels in two clinical trials (SALT-1 and SALT-2). Loop diuretics such as furosemide are very effective at increasing free water excretion. However, this mechanism is not specific for SIADH and in general loop diuretics are helpful in the acute management of SIADH but are not good options for long term treatment. Hypertonic saline is invaluable in the treatment of hyponatremia occurring due to SIADH, especially in patients who are not able to receive loop diuretics (e.g. aneurysmal subarachnoid hemorrhage patients). Urea normally accounts for about half of the daily osmolytes excreted. Treatment with urea is able to increase solute excretion and decrease urine osmolality, however its bitter taste limits clinical utility. Demeclocycline is able to treat SIADH by inducing nephrogenic diabetes insipidus. Although its precise mechanism of action remains unclear, it causes nephrogenic diabetes insipidus in about 70% of cases. Demeclocycline's clinical use is often limited by side effects such as nausea and skin photosensitivity. References: 1.Zietse R, van der Lubbe N, Hoorn EJ. Current and future treatment options in SIADH. NDT Plus. 2009 Nov;2(Suppl_3):iii12-iii19. doi: 10.1093/ndtplus/sfp154. PMID: 19881932; PMCID: PMC2762827. 2. Marik PE, Rivera R. Therapeutic effect of conivaptan bolus dosing in hyponatremic neurosurgical patients. Pharmacotherapy

57F with grade III SAH becomes progressively obtunded 3d s/p clipping of ACommA aneurysm. Laboratory studies show a serum Na level of 119 mEq/L, a serum osmolarity of 260 mOsm/L, and a urinary Na level of 40mEq/L. A post-operative CT scan shows no abnormalities. The most appropriate treatment is IV administration of which of the following agents? -DDAVP -23% NS -2% NS -IV steroids -Dextrose 5% water

2% NS. This patient is experiencing neurologic deterioration d/t acute symptomatic hypoNa. In this scenario, Na correction must be promptly, but cautiously, corrected within a few hours targeting an increase of 4-6 mEq/L (maximum 8 mEq/L ). In acute symptomatic hypoNa, a correction of 4-6 mEq/L (up to 8 mEq/L) is safe and well tolerated and can be achieved within a few hours, with close monitoring and maintenance of levels up to 24h. A more rapid correction can lead to osmotic demyelination syndrome with neurologic sequelae thereof. A slightly hypertonic saline solution like 2% normal saline can be administered, since iso-osmotic solutions can worsen hypoNa by promoting more water retention compared to sodium, potentiating SIADH. A hypotonic solution like Dextrose 5% can worsen hyponatremia. DDAVP is useful in diabetes insipidus and thus not in this scenario. A significantly hyperosmolar solution such as 23% normal saline will over-correct the sodium rapidly, which can be dangerous.

When treating a patient with acute symptomatic hypoNa with hypertonic saline, the maximum correction of plasma sodium levels in the first 24h is - >15 mEq/L - 1-4 mEq/L - 12-15 mEq/L - 4-8 mEq/L - No current guidelines

4-8. Sodium correction is based on the acuity of hyponatremia and the severity of symptoms. In acute symptomatic hyponatremia, a correction of 4-6 mEq/L (up to 8mEq/L) is safe and can be achieved within a few hours, with maintenance of stable sodium levels for up to 24 hours. A more rapid correction can lead to osmotic demyelination syndrome with neurologic sequelae thereof.

(Bank #1) The American Heart and American Stroke Associations recommend that intravenous tissue plasminogen activator (tPA) be administered no later than how long after the onset of acute ischemic stroke? -4.5h -24h -12h -2h -6h

4.5h. Administration of IV tPA is a mainstay in the management and treatment of patients with acute ischemic stroke. Initial studies demonstrated benefit for intravenous tPA given 0-3 hours after stroke onset. A later publication demonstrated utility of tPA up to 4.5 hours after stroke onset. Numerous mechanical thrombectomy trials for patients with large vessel occlusion acute ischemic strokes have demonstrated efficacy in both "early" and "late" windows, expanding the indication for this intervention to 24 hours. However, this question pertained specifically to recommendations regarding intravenous tPA administration.

A patient p/w lumbar radiculopathy requiring elective surgery. He is on apixaban for a deep venous thrombosis. Which of the following is the most appropriate amount of time to wait before operating on the patient? -4 hours after the last dose was given -12 hours after the last dose was given -48 hours after the last dose was given -24 hours after the last dose was given -6 hours after the last dose was given

48 hours after the last dose was given Discussion: This question relies on two key points of understanding: 1) the urgency of the proposed surgical intervention, and 2) the half-life of apixaban. The question stem tells us that the patient has a radiculopathy that will require elective surgery. This does not constitute an emergency that would require immediate reversal of apixaban, such as andexanet alfa. Instead, this surgery should be completed as soon as is safe after stopping apixaban - a decision made with special attention to the indication for the blood thinner and with the assistance of the physician managing it. When deciding how long to wait for surgery after administration, the literature suggests that 48 hours is the goal. Per the manufacturer, "Apixaban displays prolonged absorption. Thus, despite a short clearance half-life of about 6 hours, the apparent half-life during repeat dosing is about 12 hours, which allows twice-daily dosing to provide effective anticoagulation, but it also means that when the drug is stopped for surgery, anticoagulation persists for at least a day." The PAUSE trial cited below evaluated the perioperative management of Direct Oral Anticoagulants in patients with atrial fibrillation who were undergoing elective surgery. In patients with a low risk for bleeding complications, the authors recommend a 24-hour hold. In patients with a high risk for bleeding complications, of which neurosurgical procedures typically fall, a hold period of 48 hours is more appropriate. References: Reference (1)Eliquis. Manufacturer Product Information. Bristol-Meyers Squibb. Princeton, NJ. Pubmed Web link Reference (2) Douketis, James D et al. "Perioperative Management of Patients With Atrial Fibrillation Receiving a Direct Oral Anticoagulant." JAMA internal medicine vol. 179,11 (2019): 146

Which of the following is the normal global cerebral blood flow (CBF)? -50 mL/ (100g/min) -40 mL/ (100g/min) -20 mL/ (100g/min) -70 mL/ (100g/min) -60 mL/ (100g/min)

50. CBF = volume of blood that flows per unit mass per unit time in brain tissue. The normal value of CBF in adults is about 50 mL/100g/min. Lower values can occur in white matter [approx. 20mL/(100g/min)] and greater values can occur in gray matter [approx. 80 mL/ (100g/min)]

What are the (2) 'medium risk factors for neurosurgical intervention' to get CTH following CHI?

6. Amnesia before impact of 30 or more minutes7. Dangerous mechanism ** ** Dangerous mechanism is a pedestrian struck by a motor vehicle, an occupant ejected from a motor vehicle, or a fall from an elevation of 3 or more feet or 5 stairs.

Which of the following commonly used qualitative tests is most sensitive in detecting the therapeutic effect of dabigatran? -Activated clotting time (ACT) -Thrombin time (TT) -Activated partial thromboplastin time (aPTT) -Prothrombin time (PT) -Bleeding time

Activated partial thromboplastin time (aPTT) Discussion: Hemoclot Thrombin Inhibitor (HTI) is the most sensitive test to detect the therapeutic effect of dabigatran, but this test is not widely available and not commonly used in the clinical setting. Of the commonly used coagulation tests, activated partial thromboplastin time (aPTT) is highly sensitive and should be used to monitor dabigatran activity. References: Impact of dabigatran on a large panel of routine or specific coagulation assays. Laboratory recommendations for monitoring of dabigatran etexilate. Thromb Haemost. 2012 May;107(5):985-97 Pubmed Web link https://pubmed.ncbi.nlm.nih.gov/22438031/ Reference (2) Roslyn Bonar, Emmanuel J. Favaloro, Soma Mohammed, leonardo pasalic, John Sioufi, Katherine Marsden. The effect of dabigatran on haemostasis tests: a comprehensive assessment using in vitro and ex vivo samples. Pathology,Volume 47, Issue 4, 2015, Pages 355-364,ISSN 0031-3025, https://doi.org/10.1097/PAT.0000000000000252.

An 80M suffers L aSDH s/p craniotomy. Following surgery, he regains a withdrawal response to painful stimuli in the R arm + leg. 6h later, he is found to have new right gaze deviation and has lost this R extremity motor response. CTH shows no blood reaccumulation or shift. Which of the following is the most appropriate course of action? -RTOR -Administer IV lorazepam -MRI with DWI -CTA & CTP -Stat EEG

Administer IV lorazepam. Although a forced gaze & hemiparesis can be caused by stroke, the gaze preference of a stroke is typically opposite the side of paralysis. It would therefore be unlikely that a CTA/P or MRI would add addt'l actionable info in the short term. The pt has already had a CT to r/o post-operative hemorrhage. The most likely diagnosis is non-convulsive status. The onset of the seizure is unknown. A stat EEG (3) might be useful, but there is enough info to start Rx with a benzo such as lorazepam (4mg IV one time, repeated x1 if sz persist). A 2nd longer acting agent such as fosphenytoin, valproate, or levetiracetam should be loaded as soon as feasible. At times a SDD laying on the surface of the brain may be implicated as a source of seizure but RTOR to remove a drain would probably only be done in medically refractory cases.

55M on rivaroxaban is transferred to the emergency department with an intracerebral hematoma that requires immediate evacuation. Which of the following is the best strategy for management of this patient's coagulopathy? -IV administration of 10mg of vitamin K and proceed with surgery -Transfuse patient with FFP, cryoprecipitate, and platelets and proceed with surgery -IV administration of idarucizumab and proceed with surgery -Administration of Andexanet alfa and proceed with surgery -Proceed with surgery, anticipating major hemorrhage and multiple transfusions given no reversal agent

Administration of andexanet alfa and proceed with surgery Discussion: Patients receiving direct oral anticoagulation (DOAC) with Factor Xa Inhibitors (i.e. Rivaroxaban or Apixaban) who suffer a life-threatening hemorrhage should emergently receive a reversal agent with Andexanet-alfa. The DOAC dabigatran is a direct thrombin inhibitor, for which Idarucizumab is the reversal agent. Vitamin K would help when the patient is anticoagulated with coumadin, not a DOAC. References: Reference (1)ANNEXA-4 Investigators. Andexanet Alfa for Acute Major Bleeding Associated with Factor Xa Inhibitors. N Engl J Med. 2016 Sep 22;375(12):1131-41. Pubmed Web link https://pubmed.ncbi.nlm.nih.gov/27573206/ Reference (2) American Society of Hematology 2018 guidelines for management of venous thromboembolism: optimal management of anticoagulation therapy. Blood Adv (2018) 2 (22): 3257-3291 Pubmed Web link https://pubmed.ncbi.nlm.nih.gov/30482765/

ECG changes observed in patients with severe hyperK include which of the following? -ST-segment depression & increased PR interval -Shortened QT interval & widened QRS complex -None of the above -All of the above -Peaked T-waves

All of the above. EKG changes secondary to hyperkalemia include peaked T waves, shortened QT interval, and ST-segment depression. These changes are followed by bundle-branch blocks causing a widening of the QRS complex, increases in the PR interval and decreased amplitude of the P wave.

The MR image shown is obtained from a 32-year-old man with headache, vertigo, and ataxia. Optimal management includes which of the following? -Screening for retinal angiomas -Screening for abdominal masses -All of the other answers -Screening for pheochromocytomas -Genetic analysis

All of the other answers Discussion: Hemangioblastomas are uncommon vascular tumors of the CNS. They account for less than 3% of all CNS tumors and are generally benign, well-circumscribed, but highly vascular, neoplasms. These lesions appear as a low signal on T1-weighted images and as a high signal on T2-weighted sequences. Screening for retinal angiomas, abdominal masses, and pheochromocytomas as well as genetic analysis is recommended for every patient with a newly diagnosed hemangioblastoma. Follow-up is by MRI of the clinical neuronal region at 6 and 12-24 months postoperatively. References: Bamps S, van Calenbergh F, de Vieeschouwer S, et al. What the neurosurgeon should know about hemangioblastoma, both sporadic and in Von Hippel-Lindau disease: a literature review. Surg Neurol Int. 2013; 4:145. Blansfield JA, Choyke L, Morita SY, Choyke PL, Pingpank JF, Alexander HR, et al. Clinical, genetic and radiographic analysis of 108 patient with von Hippel-Lindau disease manifested by pancreatic neuroendocrine neoplasms. Surgery. 2007;142:814-8.

(Bank #1) 25M injured in MVC is admitted to the ICU with a GCS of 6 and CT scan demonstrating a 2cm L temporal contusion and scattered tSAH. Medical evidence-based clinical data support a 1-week course of ppx with a drug from which of the following classes? -Anticonvulsants -Barbiturates -Antibiotics -Steroids -Hyperosmolars

Anticonvulsants. Post-traumatic sz (PTS) occur either early (within 7d of injury) or late (after 7d). Clinical PTS occur in up to 12% of patients after severe TBI with electrographic sx occurring in up to 20-25% of cases. Anticonvulsant therapy is recommended to decrease the incidence of early PTS but not late PTS. Results from the CRASH trial provided Level I evidence that the use of steroids after TBI were associated with increased mortality. Therefore, the use of steroids after TBI is currently not recommended for improving outcomes or reducing ICP. Current guidelines do not recommend prophylactic use of antibiotics after TBI. While a study of 100 critically ill patients (86%) with TBI showed a decreased risk of pneumonia with cefuroxime treatment after intubation, no mortality benefit was seen and use of prophylactic antibiotics may contribute to development of resistant organisms (Am J Respir Crit Care Med. May 1997;155(5):1729-1734. PMID: 9154884). Prophylactic use of barbiturates after TBI is not recommended, although barbiturates may be used to control refractory increases in ICP. Hyperosmolar therapy is a key medical therapy for treating increased intracranial pressure, however there is no current indication for prophylactic use of hyperosmolar therapy.

(Bank #1) Which of the following factors or findings would warrant a non-contrast CTH 2h after minor closed head injury? -GCS < 15 -Vomiting, 2 or more episodes -Suspected open, depressed, and/or basal skull fx -Age 65+ -Any of the above

Any of the above. Discussion: Significant variations exist in the utilization of CT for detection of traumatic intracranial pathology among patients with minor head injuries. The Canadian CT Head Rule was derived from a prospective cohort of Canadian emergency department patients with a GCS of 13-15 after head injury. Five high-risk factors and two additional medium-risk factors were identified. The presence of any one of them indicates need for a head CT. The high-risk factors were 100% sensitive for predicting need for neurosurgical intervention, and would require only 32% of patients to undergo CT. The rule is not applicable if the patient did not experience a trauma, has a Glasgow Coma Scale score lower than 13, is younger than 16 years, is taking warfarin or has a bleeding disorder, or has an obvious open skull fracture. High Risk for Neurosurgical Intervention -1. GCS < 15 at 2h after injury -2. Suspected open or depressed skull fracture -3. Any sign of basal skull fracture * -4. Two or more episodes of vomiting -5. 65 years or older Medium Risk for Brain Injury Detection by Computed Tomographic Imaging -6. Amnesia before impact of 30 or more minutes -7. Dangerous mechanism ** * Signs of basal skull fracture include hemotympanum, racoon eyes, cerebrospinal fluid, otorrhea or rhinorrhea, Battle's sign. ** Dangerous mechanism is a pedestrian struck by a motor vehicle, an occupant ejected from a motor vehicle, or a fall from an elevation of 3 or more feet or 5 stairs. References: Stiell IG, Wells GA, Vandemheen K, et al. Variation in ED use of computed tomography for patients with minor head injury. Ann Emerg Med. 1997; 30:14-22.Stiell IG, Wells GA, Vandemheen K, et al. The Canadian CT Head Rule for patients with minor head injury. Lancet. 2001; 357:1391-6.

70F with hx of poorly controlled HTN and T2DM p/w 2-cm L thalamic hemorrhage. She has right hemiparesis but is currently awake and following commands on the L side. Blood pressure on presentation is 200/100 mmHg. Immediate management of this patient should include which of the following? -Administration of steroids -Blood pressure reduction -Emergent intubation -MRI brain -EEG

Blood pressure reduction. Patients with acute ICH need close medical attention in the initial 24-48 hours involving airway, breathing, circulatory support, after which BP control and reversal of coagulopathy is essential. The role of other diagnostic modalities in the acute settings is then considered based on clinical history. This patient is awake and alert, not requiring emergent intubation. There is no role for steroids as a therapeutic modality in spontaneous ICH.

Which of the following tests is most appropriate for differentiating b/w a traumatic LP and a pre-existing SAH? -CSF protein -CSF color -CSF cell count -CSF clarity -CSF glucose

CSF color. Xanthochromia refers to the yellow-orange discoloration of CSF, most often caused by lysis of RBCs. Discoloration begins after RBCs have been in spinal fluid for about 2h. While it sometimes can be seen visually, detection of xanthrochromia via spectrophotometry is the most reliable method of determining whether a SAH has occurred.

(Bank #1) Which of the following treatments is most appropriate for a patient with a hemolytic transfusion reaction? -Start diuretics -Emergent plasmapheresis -Administration of Ringer's lactate -Emergent steroid administration -Clinical assessment and hemodynamic support

Clinical assessment and hemodynamic support. Pts with transfusion reactions promptly need medical attn, which initially involve assessment of ABCs. First the txfn should be stopped while preserving venous access. Pts may respond to oxygen administered by nasal catheter or mask, but they may need to be intubated for mechanical ventilation. Without signs of volume overload or cardiogenic pulmonary edema, diuretics and plasmapheresis are not indicated. No evidence exists that corticosteroids or antihistamines are beneficial. Treat complications with specific supportive measures.

Inappropriate secretion of ADH can be distinguished from fluid volume overload most accurately by which of the following? -Clinical examination -UNa -UNa -SOsm -UOsm

Clinical examination. Fluid overload can best be distinguished from SIADH by clinical exam. Dx of SIADH requires an examination c/w euvolemia. Volume overload can be caused by several conditions such as heart failure, liver failure, nephrotic syndrome, or renal failure. Clinical features c/w volume overload include jugular venous distention, peripheral edema, pulmonary edema, and ascites. SOsm will be low in both SIADH & hypervolemia. UNa is typically >20 mEq/L and urine osmolality > 10 mOsm in SIADH. While urine sodium is < 20 mEq/L in heart failure, ascites, and nephrotic syndrome, hypernatremia due to renal failure may present with urine sodium well in excess of 20 mEq/L.

In a patient who underwent surgery one week ago, which of the following substances provides wound integrity and strength? -Scar Tissue -Collagen -Fibrin -Neutrophils -Macrophages

Collagen Discussion: Wound healing is a complex biological process that consists of hemostasis, inflammation, proliferation (4 days to three weeks, the time frame of this patient), and remodeling. The first hemostasis phase begins immediately after wounding, with vascular constriction and fibrin clot formation. Once bleeding is controlled, inflammatory cells migrate into the wound (chemotaxis) and promote the inflammatory phase, characterized by the sequential infiltration of neutrophils, macrophages, and lymphocytes. A critical function of neutrophils is the clearance of invading microbes and cellular debris. Macrophages are also responsible for inducing and clearing apoptotic cells, thus paving the way for the resolution of inflammation. In the proliferative phase, fibroblasts and endothelial cells are the most prominent cell types present and support capillary growth, collagen formation, and the formation of granulation tissue at the site of injury. Within the wound bed, fibroblasts produce collagen and glycosaminoglycans and proteoglycans, major components of the extracellular matrix (ECM). Scar tissue occurs during the remodeling phase and occurs over months to years. References: Guo S, Dipietro LA. Factors affecting wound healing. J Dent Res. 2010 Mar;89(3):219-29. doi: 10.1177/0022034509359125. Epub 2010 Feb 5. PMID: 20139336; PMCID: PMC2903966. Frantz C, Stewart KM, Weaver VM. The extracellular matrix at a glance. J Cell Sci. 2010 Dec 15;123(Pt 24):4195-200. doi: 10.1242/jcs.023820. PMID: 21123617; PMCID: PMC2995612.

67 yo pt is hospitalized for mgt of an acute ischemic stroke. In the ED, the patient receives IV tPA and then sustains an IPH. Which of the following is the most appropriate pharmacologic reversal agent for this pt? -Protamine -Cryoprecipitate -FFP -Vitamin K -4-factor prothrombin complex concentrate (PCC)

Cryoprecipitate. Discussion: The reversal agent of choice for tPA associated hemorrhages is cryoprecipitate which contains fibrinogen, which is depleted by tPA. If cryoprecipitate is unavailable, fresh frozen plasma (FFP) and tranexamic acid can be considered. There is no role for vitamin K or 4-factor PCC. References: Frontera JA, et al. Guideline for reversal of anti-thrombotics in intracranial hemorrhage: a statement for healthcare professionals from the neurocritical care society and society of critical care medicine. Neurocrit Care. 2016 Feb;24(1):6-46; Saghi S, Willey JZ, Cucchiara B, Goldstein JN, Gonzales NR, Khatri P, Kim LJ, Mayer SA, Sheth KN, Schwamm LH; American Heart Association Stroke Council; Council on Cardiovascular and Stroke Nursing; Council on Clinical Cardiology; and Council on Quality of Care and Outcomes Research. Treatment and Outcome of Hemorrhagic Transformation After Intravenous Alteplase in Acute Ischemic Stroke: A Scientific Statement for Healthcare Professionals From the American Heart Association/American Stroke Association. Stroke. 2017 Dec;48(12):e343-e361.

Neuronal death in the ischemic penumbra is the most likely to be mediated by which of the following proteins? -Nitric oxide -VEGF -SDF-1a -Cytochrome C -Carbon monoxide

Cytochrome C Discussion: Severe oxidative stress includes lipid peroxidation, protein dysfunction, DNA damage and finally necrosis in the ischemic core, whereas weaker damage in the penumbra elicits predominately apoptosis. Glutamate, K+, ROS, NO, acidosis, and edema spread the injury and induce penumbra formation. The relatively long-living ROS (H2O2 and O2-) diffuse between organelles and cells. They activate both pro-survival and pro-apoptotic signaling cascades. The oxidative injury of endoplasmic reticulum and mitochondrial membranes stimulates release of stored Ca2+ and mitochondrial pro-apoptotic proteins such as cytochrome c, Smac/DIABLO, AIF, endonuclease G into the cytosol (Guo et al., 2011). The cell response to acute injury is initially performed by proteins present in the cell. However, if the injury is strong and present proteins are unable to cope with the primary lesion, additional proteins are synthesized. Nitric oxide and carbon monoxide have been implicated in neuronal regeneration, not apoptosis, and are not proteins. SDF-1α and VEGF are proteins that mediate neuronal repair and regeneration. References: Moon S, Chang MS, Koh SH, Choi YK. Repair Mechanisms of the Neurovascular Unit after Ischemic Stroke with a Focus on VEGF. Int J Mol Sci. 2021 Aug 9;22(16):8543 Broughton BR, Reutens DC, Sobey CG. Apoptotic mechanisms after cerebral ischemia. Stroke. 2009 May;40(5):e331-9. Uzdensky AB. Regulation of apoptosis in the ischemic penumbra in the first day post-stroke. Neural Regen Res. 2020 Feb;15(2):253-254. doi: 10.4103/1673-5374.265546. PMID: 31552891; PMCID: PMC6905348.

67M who receives HD has acute onset large SDH. Surgical evacuation is complicated by difficulty controlling bleeding from the scalp and the contused brain surface. Hemoglobin is 8, plt 162K, prothrombin time (PT) is 13.2s (N 11-13.5). The patient is HDS. Which of the following is the most appropriate next step in mgt? -Administer DDAVP -Administer FFP -Administer TXA -Administer 4-factor PCC -Administer protamine

DDAVP. Discussion: Uremia/renal failure pts develop an acquired deficiency in plt function caused by decreased thromboxane A2 function, increased platelet-inhibitory prostaglandin, and excessive nitric oxide synthesis. In pt who is HDS w/difficult to control intraop bleeding, administration of cryoprecipitate or DDAVP would be the best initial step in mgt. Postop dialysis may be considered as well. DDAVP increases the plasma levels of factor VIII and vWF and shortens the partial thromboplastin time (PTT) and bleeding time. DDAVP has no effect on plt count or aggregation, but it enhances plt adhesion to the vessel wall. A short-lived effect of DDAVP is the release of large amt of tPA into the plasma. References: Escolar G, Díaz-Ricart M, Cases A. Uremic platelet dysfunction: past and present. Curr Hematol Rep. 2005 Sep;4(5):359-67.Medow JE, Dierks MR, Williams E, et al. The Emergent Reversal of Coagulopathies Encountered in Neurosurgery and Neurology: A Technical Note. Clin Med Res. 2015; 13(1): 20-31.Hedges SJ, Dehoney SB, Hooper JS, Amanzadeh J, Busti AJ. Evidence-based treatment recommendations for uremic bleeding. Nat Clin Pract Nephrol. 2007 Mar;3(3):138-53. doi: 10.1038/ncpneph0421. PMID: 17322926.Frontera JA, Lewin JJ 3rd, Rabinstein AA, Aisiku IP, Alexandrov AW, Cook AM, del Zoppo GJ, Kumar MA, Peerschke EI, Stiefel MF, Teitelbaum JS, Wartenberg KE, Zerfoss CL. Guideline for Reversal of Antithrombotics in Intracranial Hemorrhage: A Statement for Healthcare Professionals from the Neurocritical Care Society and Society of Critical Care Medicine. Neurocrit Care. 2016 Feb;24(1):6-46. doi: 10.1007/s12028-015-0222-x. PMID: 26714677.

The randomized controlled Decompressive Craniectomy in Patients with Severe TBI (DECRA) trial concluded that patients who received a craniectomy for severe TBI injury experienced which of the following? -Fewer complications -Higher mortality -Decreased ICP -Better functional outcomes -No benefit

Decreased ICP. The DECRA trial randomized patients to continued medical mgt (pentobarbital coma) or surgical decompression of the patient was refractory to most ICP measures. The study found that patients who had surgical decompression had fewer episodes of elevated ICP and fewer days in the ICU. They had similar mortality to the medical group but unfavorable outcomes. Criticisms of this trial including failure of randomization as well as too early to decompression in the surgical group.

According to the results of a prospective, randomized, controlled trials, which of the following best describes the effect of therapeutic hypothermia in pts with a severe TBI? -Attenuation of the release of excitatory neurotransmitters following severe TBI -Insufficient evidence for its utilization in the mgt of pts with severe TBI -Decreased incidence of myocardial ischemia -Improved GOS-E at 30 days -Decreased incidence of venous thromboembolic complications

Despite a large # of studies, there remains no high-quality evidence that hypothermia is beneficial in the treatment of patients with severe TBI. While hypothermia may be associated with a decreased release of excitatory neurotransmitters (which, along with reducing cerebral metabolic rate, may explain its MOA) there is insufficient evidence to show that therapeutic hypothermia improves mortality or long-term functional outcomes. The main risks associated with therapeutic hypothermia include increased risk of infectious complications, coagulation abnormalities, MI, and A-Fib.

23F is admitted to the ICU s/p unrestrained high-speed MVC. Pulse is 44/min and regular, respirations are 16/min, BP is 68/40 mmHg, and central venous pressure is 2 mmHg. Fluid resuscitation is initiated, but the patient remains hypotensive and bradycardic. Which of the following is the most likely cause of shock and the most appropriate treatment? -Cardiogenic Shock- sympathomimetic vasopressors + fluid replacement -Obstructive Shock- immediate causal treatment -None of the above -Distributive Shock- sympathomimetic vasopressors + fluid replacement -Hypovolemic Shock- fluid resuscitation (balance crystalloids)

Distributive Shock - sympathomimetic vasopressors + fluid replacement Discussion: This patient most likely is in a state of neurogenic shock, characterized by bradycardia, hypotension, and low central venous pressures. Neurogenic shock is a state of imbalance between sympathetic and parasympathetic regulation of cardiac action and vascular smooth muscle. The dominant signs are profound vasodilation with relative hypovolemia while blood volume remains unchanged, at least initially. Neurogenic shock is classified as a type of distributive shock. The primary treatment of neurogenic/distributive shock is fluid resuscitation (typically balanced crystalloids) and administration of sympathomimetic (norepinephrine, epinephrine) vasoactive medications.Hypovolemic shock is a condition of inadequate organ perfusion caused by loss of intravascular volume, usually acute. Early hypovolemic shock is typically characterized by tachycardia and hypotension and low central venous pressures.Cardiogenic shock is primarily a disorder of cardiac function in the form of a critical reduction of the heart's pumping capacity, caused by systolic or diastolic dysfunction leading to a reduced ejection fraction or impaired ventricular filling. Patients with cardiogenic shock may be either tachycardic or bradycardic, however, central venous pressures are usually high.Obstructive shock is a condition caused by the obstruction of the great vessels or the heart itself. Although the symptoms resemble those of cardiogenic shock, obstructive shock needs to be clearly distinguished from the latter because it is treated quite differently. The treatment of obstructive shock is causal - thrombolysis of pulmonary embolism, tension pneumothorax or cardiac tamponade by thoracic/pericardial drainage. Central venous pressures would be expected to be high in ob

(Bank #1) A LP in a pt with pseudotumor cerebri will show which of the following? -Elevated opening pressure -Pleocytosis -Elevated IgG index -Low glucose -High protein

Elevated opening pressure. Pseudotumor cerebri is a disorder of idiopathic intracranial hypertension (IIH). It often affects young, obese women who p/w H/A, papilledema, and elevated LP opening pressure. The chemical and cellular composition of the CSF is usually normal. 1st line Rx is typically administration of acetazolamide wwo furosemide. If vision is acutely threatened, temporary CSF drainage by LP or LD may allow a trial of these diuretics. Options for more permanent treatment are optic nerve sheath (ONS) fenestration and VPS. Although the latter is the gold standard, it's often fraught w complications over time in this pt population. The venous sinuses and jugular veins should be imaged as stenting can be considered for stenosis as an alternative to VPS.

For which of the following indications has the United States Food and Drug Administration approved the use of the serum biomarkers glial fibrillary acidic protein (GFAP) and ubiquitin carboxy-terminal hydrolase-L1 (UCH-L1)? -Predicting the outcome from aneurysmal subarachnoid hemorrhage -Monitoring efficacy of chemotherapy for malignant primary brain tumor -Evaluation of mild traumatic brain injury -Evaluation of elevated intracranial pressure -Monitoring efficacy of treatment for non-convulsive status epilepticus

Evaluation of mild traumatic brain injury Discussion: The United States Food and Drug Administration has approved the use of the serum biomarkers glial fibrillary acidic protein (GFAP) and ubiquitin carboxy-terminal hydrolase-L1 as clinically validated early time biomarkers for mild traumatic brain injury (mTBI) at early time points. The elevation of UCH‐L1 and GFAP in biofluids was associated with injury severity and clinical outcomes. The use of one diagnostic test with these tandem markers was authorized by the FDA to aid in the diagnosis and care of mTBI patients. Cellular damage, resulting from brain injury, leads to the release of cell‐type‐specific proteins into biofluids such as cerebral spinal fluid (CSF), serum, plasma, or blood. Several characteristics allow biofluid markers to be clinically significant, amongst which is the availability of the protein and the ability to readily determine and quantify it. Additionally, biomarkers should increase significantly in the acute phase post‐TBI as compared to control subjects, should be brain‐specific, and should be highly sensitive, reflecting the severity of the TBI. Several biomarkers have been identified as indicators of TBI pathophysiological events, including necrosis (SBDP150, SBDP145, and SNTF), apoptosis (SBDP120), neuronal cell body injury (UCH‐L1 and NSE), strogliosis/astroglia injury (GFAP), and inflammation (interleukin‐6 and autoantibodies) and neurodegeneration (Tau, pTau). References: Samson K. In the Clinic-Traumatic Brain Injury FDA Approves First Blood Test for Brain Bleeds After Mild TBI/Concussion. Neurology Today. 2018;18(6):1-37. Wang KKW, Kobeissy FH, Shakkour Z, Tyndall JA. Thorough overview of ubiquitin C-terminal hydrolase-L1 and glial fibrillary acidic protein as tandem biomarkers recently cleared by US Food and Drug Admi

36M has closed fx of femur and small, focal area of SAH after being involved in MVC. No other cranial injury is noted, and neurologic exam is normal. After repair of the femur fx, the patient does not arouse from anesthesia. CTH shows bilateral diffuse, small, hypodense lesions. Which of the following is most likely cause of the change in this patient's clinical status? -Watershed infarcts from hypotension -Posterior reversible encephalopathy syndrome (PRES) -Diffuse embolic infarcts -Diffuse axonal injury (DAI) -Fat emboli

Fat emboli. The presence of femur fx and diffuse hypodense lesions would be indicative of fat emboli. One would expect DAI to yield an immediate neurological deficit. There is no reported HoTN that would yield watershed infarcts, and the close proximity to the femur repair would make diffuse embolic infarcts and PRES less likely.

Which of the following conditions increases the cerebral metabolic rate (CMRO2)? -Barbiturate coma -Hyperoxygenation -Brain injury -Fever -General anesthesia

Fever. Rate of oxygen consumption by the brain is known as cerebral metabolic rate of oxygen (CMRO2). The rate of oxygen consumption is decreased by sedatives such as barbiturates and GA. Brain injury will aso tend to reduce brain metabolism, particularly in the acute phase. Hyperoxia on its own will not stimulate brain metabolism. Fever has been shown to increase CMRO2. This is a major reason why prevention of fever is considered important in patients who are prone to brain ischemia.

HIGH YIELD. 63M sustains a hemorrhagic p-fossa stroke and is taken to the OR for emergency surgical evacuation. the patient is placed in the lateral position for the procedure. Shortly after elevating the bone flap, the end-tidal CO2 and O2 saturation decrease, leading to a decrease in the patient's blood pressure. Which of the following is the most appropriate course of action? -Immediately close the wound and prepare for reintubation -Resect cerebellar hemisphere to relieve pressure -Immediate place an EVD at Frazier's point -Flood the field with saline -Increase PEEP

Flood the field with saline. A drop in ET-CO2 and O2 saturation during posterior fossa surgery likely represents a venous air embolus due to air entering non-compressed veins such as the dural sinuses and bony venous lakes during the craniotomy. The first step for the surgeon is to flood the field with saline and/or cover the field with saline soaked sponges to help seal the veins off from the air. Posterior fossa swelling requiring tissue resection or a ventricular drain would not likely cause significant changes in the oxygenation status of a mechanically intubated patient. Increasing PEEP might be considered initially but is not likely to be effective as the air embolus affects perfusion not ventilation. Disconnection of the ventilator or dislodgment of the ET tube might result in a drop in ET-CO2 and O2 sat, but would not likely cause hypotension, at least initially.

Which of the following is most likely to result from a jugular venous oxygen saturation of less than 50%? -Global cerebral hypoxia -Barbiturate coma -Hyperperfusion syndrome -Posterior fossa ischemia -ICA-MCA tandem occlusion and stroke

Global cerebral hypoxia. Discussion: Jugular venous oxygen saturation is typically measured using a central line catheter inserted retrograde in the internal jugular vein with the tip in the jugular bulb. Depending on the equipment used, intermittent or continuous sampling of the oxygen saturation of the blood exiting the brain via the jugular vein can be measured. Typical measurements range from 50% to 75%. During global cerebral hypoxia, decreased oxygen delivery will cause an increase in oxygen extraction in the capillary bed and a drop in the jugular venous oxygenation below 50%. While an ICA-MCA occlusion will certainly cause ischemia, complete absence of flow may not cause a measurable increase in oxygen extraction as there can be no increase in oxygen extraction if flow drops to zero. Posterior fossa ischemia will often not result in a change jugular venous oxygen saturation for two reasons. First, the catheter is usually placed on the dominant side which is the side typically draining the supratentorial space. Second, the posterior circulation only accounts for 15-20% of total brain metabolism so its contribution to overall oxygen extraction is fairly small. Cerebral hyper perfusion syndrome and barbiturate coma would be expected to result in excess oxygen delivery and therefore an increase in jugular venous oxygen saturation above 75%. References: Ullman JS: Cerebral blood flow and metabolism in Intensive Care in Neurosurgery. Andrews BT, ed. New York, Thieme, pp29-46, 2003.Schell, Randall M., and Daniel J. Cole. 2000. "Cerebral Monitoring: Jugular Venous Oximetry." Anesthesia & Analgesia 90 (3): 559.

Which of the following are the most common findings of CSW syndrome? -Hypernatremia, elevated urine Na, elevated UOsm, hypovolemia -Hyponatremia, elevated urine Na, decreased UOsm, hypovolemia -Hypernatremia, elevated urine Na, elevated UOsm, hypervolemia -Hyponatremia, elevated urine Na, elevated UOsm, hypovolemia -Hyponatremia, decreased urine Na, elevated UOsm, hypovolemia

HypoNa, Elevated UNa, Elevated UOsm, hypovolemia. Evaluation for CSW begins with a BMP to identify the hyponatremia. Urine studies are commonly checked for urine sodium and osmolality. Urine sodium is typically elevated above 40 meq/L. Urine osmolality is elevated above 100 mosmol/kg. The patient must also have signs or symptoms of hypovolemia such as hypotension, decreased central venous pressure, lack of skin turgor, or elevated hematocrit. SIADH will have a similar laboratory picture as cerebral salt wasting with hyponatremia and increased urine sodium. However, with SIADH, the patient is euvolemic to hypervolemic from the retained free water as compared to the hypovolemic picture of cerebral salt wasting.

55M on clopidogrel is transferred to the ED with an intracerebral hematoma that requires immediate evacuation. Which of the following is the best strategy for management of this patient's coagulopathy? -IV administration of idarucizumab and proceed with surgery -IV administration 0.4ug/kg of desmopressin followed by platelet transfusion -IV administration of 10mg of Vitamin K and proceed with surgery -Proceed with surgery, anticipating major hemorrhage and multiple transfusions given no reversal agent -IV administration of protamine sulfate and proceed with surgery

IV administration 0.4ug/kg of desmopressin followed by platelet transfusion Discussion: Although, currently, there is no specific reversal agent for clopidogrel, it is recommended that patients receive a single dose of 0.4μg/kg of desmopressin intravenously followed by platelet transfusion. Desmopressin acts by increasing plasma von Willebrand factor, factor VIII and intracellular platelet calcium/sodium ion concentrations, as well as, increasing formation of procoagulant platelets and platelet adhesion to collagen. Idarucizumab is the reversal agent for the direct thrombin inhibitor dabigatran. Protamine sulfate is the reversal agent for heparin. Vitamin K would help when the patient is anticoagulated with coumadin. References: Reference (1)Guideline for Reversal of Antithrombotics in Intracranial Hemorrhage: Executive Summary. A Statement for Healthcare Professionals From the Neurocritical Care Society and the Society of Critical Care Medicine. Crit Care Med. 2016 Dec;44(12):2251-2257. Pubmed Web link https://pubmed.ncbi.nlm.nih.gov/27858808/ Reference (2) Desmopressin for treatment of platelet dysfunction and reversal of antiplatelet agents: a systematic review and meta-analysis of randomized controlled trials. J Thromb Haemost. 2017 Feb;15(2):263-272 Pubmed Web link https://pubmed.ncbi.nlm.nih.gov/27893176/

55M on dabigatran is transferred to the emergency department with an intracerebral hematoma that requires immediate evacuation. Which of the following is the best strategy for management of this patient's coagulopathy? -IV administration of 5mg vitamin K and proceed to the operating room -Administer four-factor prothrombin complex concentrate (4F-PCC) and IV vitamin K and proceed to the operating room -IV administration of 5g idarucizumab once on the way to the operating room -Proceed to the operating room anticipating major hemorrhage as there is no reversal agent -Emergent hemodialysis on the way to the operating room

IV administration of 5g idarucizumab once on the way to the operating room Discussion: Idarucizumab (praxbind) is a humanized antibody fragment against the thrombin-binding site of dabigatran. Idarucizumab rapidly, durably, and safely reverses the anticoagulant effect of dabigatran and is the preferred agent for reversal. 4F-PCC is an option for direct oral anticoagulant reversal and can be utilized in situations when idarucizumab is not available. Direct oral anticoagulants directly inhibit specific proteins within the coagulation cascade. Vitamin K is used for warfarin reversal, but its effect is not immediate. Hemodialysis can be used to clear dabigatran in patients with renal failure, and can be utilized after idarucizumb administration to clear dabigatran-idarucizumab complexes in patients with renal failure. References: 1. Medow JE, Dierks MR, Williams E, Zacko JC. The emergent reversal of coagulopathies encountered in neurosurgery and neurology: a technical note. Clin Med Res. 2015;13(1):20-31. doi:10.3121/cmr.2014.1237 2. Frontera JA, Lewin JJ 3rd, Rabinstein AA, Aisiku IP, Alexandrov AW, Cook AM, del Zoppo GJ, Kumar MA, Peerschke EI, Stiefel MF, Teitelbaum JS, Wartenberg KE, Zerfoss CL. Guideline for Reversal of Antithrombotics in Intracranial Hemorrhage: A Statement for Healthcare Professionals from the Neurocritical Care Society and Society of Critical Care Medicine. Neurocrit Care. 2016 Feb;24(1):6-46. doi: 10.1007/s12028-015-0222-x. PMID: 26714677. 3. Pollack CV Jr, Reilly PA, van Ryn J, Eikelboom JW, Glund S, Bernstein RA, Dubiel R, Huisman MV, Hylek EM, Kam CW, Kamphuisen PW, Kreuzer J, Levy JH, Royle G, Sellke FW, Stangier J, Steiner T, Verhamme P, Wang B, Young L, Weitz JI. Idarucizumab for Dabigatran Reversal - Full Cohort Analysis. N Engl J Med. 2017 Aug 3;377(5):431-441. doi: 10.1056/NEJMoa170727

55M on warfarin for atrial fibrillation is transferred to the ED with an intracerebral hematoma that requires immediate evacuation. Twelve hours prior, his international normalized ratio (INR) was 4.0. Which of the following is the best strategy for management of this patient's coagulopathy? -Administer four-unit fresh frozen plasma (4U-FFP) and proceed to the operating room -IV administration of 5mg vitamin K and 4F-PCC and proceed to the operating room -Proceed to the operating room as half-life of warfarin is eight hours and anticoagulation is already reversed -Administer 5mg oral vitamin K via gastronomy tube and proceed to the operating room -Administer four-factor prothrombin complex concentrate (4F-PCC) only and proceed to the operating room

IV administration of 5mg vitamin K and 4F-PCC and proceed to the operating room Discussion: The optimal reversal strategy is to administer 4 factor PCC immediately given its rapid effect, especially when immediate surgery is required, and concurrent adminstration of vitamin K to replenish the clotting factors inhibited by warfarin. PCC is unactivated prothrombin complex concentrate, and 4F PCC is PCC containing coagulation factors II, VII, IX, X, protein S and protein C. Fresh frozen plasma (FFP) administration is an alternative but the hemostatic effect is delayed. FFP can take hours to reverse the anticoagulation effect of warfarin due to the volume required. Vitamin K administration by itself would not provide immediate hemostasis. References: Medow JE, Dierks MR, Williams E, Zacko JC. The emergent reversal of coagulopathies encountered in neurosurgery and neurology: a technical note. Clin Med Res. 2015;13(1):20-31. doi:10.3121/cmr.2014.1237 Frontera JA, Lewin JJ 3rd, Rabinstein AA, Aisiku IP, Alexandrov AW, Cook AM, del Zoppo GJ, Kumar MA, Peerschke EI, Stiefel MF, Teitelbaum JS, Wartenberg KE, Zerfoss CL. Guideline for Reversal of Antithrombotics in Intracranial Hemorrhage: A Statement for Healthcare Professionals from the Neurocritical Care Society and Society of Critical Care Medicine. Neurocrit Care. 2016 Feb;24(1):6-46

26M p/w severe H.A and new-onset sz. MRI Brain with SSS thrombosis and small R parietal hemorrhagic venous infarction causing minimal mass effect. Patient is lethargic but easily arousable, follows complex commands on the right. Which of the following is the most appropriate initial mgt strategy? -Ventriculostomy -Transvenous endovascular thrombectomy -Craniotomy and evacuation of the hematoma -IV anticoagulation -Mannitol and serial imaging

IV anticoagulation. Pt has had hemorrhagic venous infarction d/t thrombosis of SSS. Sz are common presenting symptom of ICH. Current AHA/ASA guidelines suggest IV anticoagulation as initial mgt strategy of venous sinus thrombosis, even in presence of ICH. Mannitol is probably not indicated in this pt as there is little mass effect and dehydration may precipitate further thrombosis. This patient is not suffering from significant ME, so clot evacuation is not indicated and would delay administration of anticoagulation. The pt. is arousable and doesn't ahve HCP, therefore CSF drainage and invasive ICP monitoring via a ventriculostomy are not indicated. Transvenous endovascular thrombectomy can be considered in patients who are refractory to medical mgt or perhaps to patients who present in extremis, but is not typically 1st line therapy.

A 55M on apixaban is transferred to the ED with an intracerebral hematoma that requires immediate evacuation. Which of the following is the best strategy for management of this patient's coagulopathy? -Emergent hemodialysis on the way to the operating room -IV administration of 5 mg vitamin K and proceed to the operating room -Proceed to the operating room anticipating major hemorrhage as there is no reversal agent -IV administration of 5 g idarucizumab once on the way to the operating room -IV bolus administration of 800 mg andexanet alfa followed by infusion of 8 mg/min for 120 minutes

IV bolus administration of 800 mg andexanet alfa followed by infusion of 8mg/min for 120 minutes Discussion: Apixaban is a direct factor Xa inhibitor. Apixaban is recommended for the prevention of stroke and systemic embolism in those with non-valvular atrial fibrillation and at least one of the following risk factors: prior stroke or transient ischemic attack, age 75 years or older, diabetes mellitus, or symptomatic heart failure. Andexanet alfa is recombinant modified human factor Xa protein that binds directly to free-floating factor Xa inhibitors with high affinity, sequestering them, and thus rapidly reducing the free plasma concentration of these agents, neutralizing their anticoagulant effect. Andexanet alfa is a Food and Drug Administration (FDA) approved antidote for apixaban in people with uncontrolled and life-threatening bleeding events. Emergent dialysis and idarucizimab administration are reversal strategies for dabigatran. Vitamin K is part of the reversal strategy for warfarin along with fresh frozen plasma, or 4 factor prothrombin complex concentrate in cases in which warfarin needs to be reversed quickly. References: Medow JE, Dierks MR, Williams E, Zacko JC. The emergent reversal of coagulopathies encountered in neurosurgery and neurology: a technical note. Clin Med Res. 2015;13(1):20-31. doi:10.3121/cmr.2014.1237 Frontera JA, Lewin JJ 3rd, Rabinstein AA, Aisiku IP, Alexandrov AW, Cook AM, del Zoppo GJ, Kumar MA, Peerschke EI, Stiefel MF, Teitelbaum JS, Wartenberg KE, Zerfoss CL. Guideline for Reversal of Antithrombotics in Intracranial Hemorrhage: A Statement for Healthcare Professionals from the Neurocritical Care Society and Society of Critical Care Medicine. Neurocrit Care. 2016 Feb;24(1):6-46 Greenberg SM, Ziai WC, Cordonnier C, Dowlatshahi D, Francis B, Goldstein JN, Hemphill JC 3rd, Johnson

Vitamin C is most likely to enhance wound healing in patients in the ICU by promoting which of the following? -Deactivation of self-renewal wound healing genes -Increased fibroblast motility -Decreased expression of growth factor cytokines -Increased transcription of pro-inflammatory genes -Decreased fibroblast proliferation

Increased fibroblast motility Discussion: Vitamic C affects wound healing in multiple ways, including activation of self-renewal genes, decreasing transcription of pro-inflammatory genes, increasing expression of growth factor cytokines and increasing fibroblast proliferation and motility. References: Mohammed BM, Fisher BJ, Kraskauskas D, Ward S, Wayne JS, Brophy DF, Fowler AA 3rd, Yager DR, Natarajan R. Vitamin C promotes wound healing through novel pleiotropic mechanisms. Int Wound J. 2016 Aug;13(4):572-84 Duarte TL, Cooke MS, Jones GD. Gene expression profiling reveals new protective roles for vitamin C in human skin cells. Free Radic Biol Med. 2009 Jan 1;46(1):78-87.

(Bank #2) A 40-year-old woman is being treated with pressure-support mechanical ventilation following a severe subarachnoid hemorrhage. Close monitoring of which of the following is most likely to assure adequate minute ventilation? -Inspiratory pressure and positive end-expiratory pressure -Respiratory rate and positive end-expiratory pressure -Tidal Volume -Tidal volume and respiratory rate -Inspiratory pressure and respiratory rate

Inspiratory pressure and respiratory rate The minute ventilation is the amount of air a person breaths in a minute. The minute ventilation is calculated by the multiplication of the tidal volume and the respiratory rate. On pressure-support mode of ventilation, minute ventilation is adjusted by changes in inspiratory pressure and based on the respiratory rate that the patient is triggering. The tidal volume is not manually adjustable on pressure-controlled modes of ventilation. A person requires a minimum of 6 to 8 litres of minute volume for the proper oxygenation of the tissues and the removal of carbon dioxide from the lungs. The minute volume increases at times of stress and exercise. This increase compensates for the increase in the demand of oxygen and the increased production of carbon dioxide, usually by increase in respiratory rate.

Which of the following intravenous opioids has the slowest peak onset of effect? -Sufentanil -Morphine -Remifentanil -Methadone -Alfentanil

Morphine Discussion: Alfentanil and remifentanil are very fast equilibrating opioids with equilibration half-lives between plasma and effect site of around 1 minute. They are followed by fentanyl and sufentanil, with equilibration half-lives of about 6 minutes. Methadone equilibrates with a half-life of about 8 min. Finally, morphine, equilibrates with a half-life of 2-3 h. PK/PD modeling has advanced the understanding of the time course of the clinical effects of opioids after various dosing regimens. References: Kharasch ED. Intraoperative methadone: rediscovery, reappraisal, and reinvigoration? Anesth Analg. 2011 Jan;112(1):13-6.2. Lötsch J. Pharmacokinetic-pharmacodynamic modeling of opioids. J Pain Symptom Manage. 2005:29:S90-103. Ing Lorenzini K, Daali Y, Dayer P, Desmeules J. Pharmacokinetic-pharmacodynamic modelling of opioids in healthy human volunteers. a minireview. Basic Clin Pharmacol Toxicol. 2012 Mar;110(3):219-26. doi: 10.1111/j.1742-7843.2011.00814.x. Epub 2011 Nov 9. PMID: 21995512.

Which of the following describes the mechanism of action of remifentanil? -Kappa opioid receptor antagonist -Mu opioid receptor antagonist -Mu opioid receptor agonist -GABA-A receptor agonist -Kappa opioid receptor agonist

Mu opioid receptor agonist Remifentanil's is as an agonist of the mu opioid receptor. It is a short acting agent used for sedation and general anesthesia. Butorphanol and Nalbuphine are kappa opioid receptor agonists used for analgesia. Naltrexone is an antagonist for mu opioid receptors but less effective for kappa opioid receptors and used to reverse effects of opioid medications. Benzodiazepines are GABA-A agonists.

A patient who has severe asthma requires administration of an anti-HTN drug. Which of the following drug classes is contraindicated in this patient? -Non-selective beta-blockers -Calcium channel blockers -Angiotensin receptor blockers (ARBs) -ACE inhibitors -Diuretics

Non-selective beta-blockers should not be prescribed for the mgt of comorbidities in patients with asthma while cardio-selective B-blockers, preferably in low doses, may be used when strongly indicated and other therapeutic options are not available. There are no contraindications to use of diuretics, ACE inhibitors, or ARBs in patients with asthma.

20M in septic shock has SBP of 80mmHg. Infusion of which of the following is recommended to increase his BP and improve cardiac output? -Vasopressin -Epinephrine -Amiodarone -Norepinephrine -Dopamine

Norepinephrine is the 1st line vasopressor in shock and is associated with a lower mortality rate as well as fewer adverse effects. Dopamine has similar actions but is associated with significantly more tachydysrhythmias and should be reserved for patients with bradycardia. Epinephrine and vasopressin are appropriate 2nd line vasopressors and may enable use of lower doses of norepinephrine while improving hemodynamics. Inotropes may be added in patients with cardiac dysfunction.

Timed vital capacity measurements are most definitive in the detection of which of the following? -Need for a tracheostomy -Strength of diaphragm -Obstructive Lung Disease -Readiness to wean from a ventilator -Restrictive lung disease

Obstructive Lung Disease Discussion: Timed vital capacity is a test of the vital capacity of the lungs expressed with respect to the volume of air that can be quickly and forcibly breathed out in a certain amount of time. It is a sensitive test for obstructive lung disease. It does not help diagnose restrictive lung disease as that makes it difficult to inhale, not exhale. Timed vital capacity cannot be measured in an intubated patient. References: Sobol BJ, Emirgil C. The First Second Timed vital capacity and the course of obstructive lung diseases. Chest. 1977 Jul;72(1):81-3. doi: 10.1378/chest.72.1.81. PMID: 872660. Miller A. Screening tests for pulmonary function abnormality. Environ Health Perspect. 1975 Jun;11:243-6. doi: 10.1289/ehp.7511243. PMID: 1175563; PMCID: PMC1475188.

64F evaluated for painful, swollen, warm R calf 6 wks s/p lumbar laminectomy. Doppler US shows extensive DVT. Which of the following is the most appropriate next step in mgt? -Placement IVCf -Initiation of oral anticoagulation therapy -Initiation of IV anticoagulant therapy -No treatment is needed -Initiation of antiplatelet medication

Oral anticoagulation. For primary treatment of patients with DVT and/or PE, whether provoked by a transient risk factor or by a chronic risk factor or unprovoked, the ASH guideline panel suggests using a shorter course of anticoagulation for primary treatment (3-6 months) over a longer course of anticoagulation for primary treatment (6-12 months). Oral anticoagulation is the preferred method. These recommendations apply to patients who are eligible to receive anticoagulation. For patients with a contraindication to anticoagulation, insertion of a retrievable IVC filter may be indicated, with retrieval as soon as the patient is able to receive anticoagulation.

46F is recovering 5d s/p clipping of ruptured ACommA aneurysm that presented with World Federation of Neurosurgical Societies (WFNS) grade 1 SAH. She is neurologically intact. Routine management of this patient in the ICU includes which of the following? -Prophylactic cerebral angioplasty -Oral nimodipine -Hemodilution to hematocrit of 33 -Maintaining SBP < 140 -Daily TCDs

Oral nimodipine has been shown in RCT to reduce the risk of delayed ischemic events after aSAH. It is common practice to keep the SBP < 160 mmHg prior to securing a ruptured aneurysm. Once the aneurysm is secured, permissive HTN rather than anti-HTN therapy is common practice. Patients without vasospasm should be kept euvolemic. Prophylactic angioplasty is not recommended for patients with aSAH, regardless of the grade.

30M with hx of alcohol abuse is admitted to the neurointensive care unit with AMS following mild head trauma. Serum sodium level is 109 mEq/L; 3% sodium chloride is initiated. Over the next 36h, Na level normalizes, but mental status deteriorates, and the patient becomes dysarthric and quadriparetic. This patient's deterioration is most likely due to which of the following? -Alcohol withdrawal -Osmotic demyelination -Arterial vasospasm -Thiamine deficiency -Epileptic seizure

Osmotic demyelination. The patient is experiencing neurologic deterioration d/t rapid over-correction of acute symptomatic hypoNa, leading to osmotic demyelination syndrome characterized by delayed neurologic deterioration after 2-6 days of sodium correction. Symptoms consist of dysarthria, dysphagia, paraparesis/quadriparesis, seizures, lethargy, coma. In this scenario, sodium correction must be promptly, but cautiously, corrected up to 4-6 mEq/L (maximum 8mEq/L) in a 24 hour period. Arterial spasm and epileptic seizures would not be expected in mild TBI, given the context of sodium correction. Alcohol withdrawal would be associated with tremors, diaphoresis and hemodynamic instability. Thiamine deficiency is possible but does not follow the temporal course of the over-correction of hyponatremia and associated neurologic deterioration.

43F has a generalized seizure and develops severe HTN (SBP > 180 mmHg) immediately after undergoing resection of a R frontal lobe oligodendroglioma. She is conscious, but is unable to visually identify objects. All other neurological functions, including pupillary reflexes and language functions, are normal. An MR image of the brain is shown. Which of the following is the most likely diagnosis? -Progressive multifocal leukencephalopathy (PML) -Posterior cerebral artery (PCA) infarct -Central retinal artery occlusion (CRAO) -Artery of percheron infarct -Posterior reversible encephalopathy syndrome (PRES)

PRES Discussion: This patient most likely has posterior reversible encephalopathy syndrome (PRES). PRES results in impaired cerebral autoregulation. Systemic hypertension is an important contributor to the blood-brain barrier breakdown seen in PRES. Other factors likely include endothelial dysfunction, cytokines, vascular endothelial growth factor (VEGF), an imbalance of female reproductivbe hormones, enhanced oxidative stress, certain single nucleotide polymorphisms, micro-RNAs, and autonomic dysregulation. PRES results in white matter rarefaction, endothelial swelling, fibrinoid vascular necrosis, scattered microinfarcts, gliosis, and hemosiderin deposition. Imaging findings in PRES include MRI T2/fluid-attenuated inversion recovery (FLAIR) hyperintensities usually located posteriorly in the parietooccipital and frontal lobes. These lesions are due to reversible vasogenic edema. While most lesions are reversible within days to weeks, up to one-third of patients develop heterogenous lesions with ares of restricted diffusion that are not reversible.Up to one-fourth of patients may develop lobar brain hemorrhages or convexity subarachnoid hemorrhage. Patients who are hypertensive, have renal failure, are immunocompromised, or who are receiving chemotherapy are at particular risk. In addition to elevated blood pressure, patients with PRES often present with confusion or encephalopathy and up to two-thirds develop generalized tonic-clonic seizures. Visual symptoms can include blurriness, scotomas, and blackout of vision suggesting cortical blindness. Vision typically recovers except in the relatively rare cases of patients developing occipital infarcts or hemorrhages. Patients with a central retinal artery occlusion (CRAO) will often have an afferent pupillary defect (APD) on examination. A posterior cerebral artery (PCA

(Bank #1) Which of the following parameters should be confirmed before a formal apnea test can be performed? -PaO2 is normal or elevated -Absence of deep tendon reflexes -No uptake on nuclear medicine perfusion test -Non-responsive EEG -Patient has no autonomic responses (flushing, sweating)

PaO2 is normal or elevated. The apnea test is generally the last test performed to determine brain death. After confirming the patient is in an irreversible coma and that there are no brainstem reflexes, the patient is pre-oxygenated, taken off the ventilator, and observed for evidence of spontaneous breathing. If the patient remains apneic when the PaCO2 reaches ≥ 60 mm Hg (or 20 mm Hg over baseline) the patient is declared brain dead. Prior to initiating the test it must be confirmed that the PaO2 is normal and is typical to preoxygenate to a PaO2 > 200. After taking the patient off the ventilator, oxygen is continuously supplied through a catheter threaded down the ET tube to ensure the patient is not hypoxic during the test. Ancillary tests such as a nuclear medicine perfusion test or EEG may be performed when apnea testing is indeterminate but are not required for the determination of brain death or as a qualification for the apnea test. Autonomic functions and DTRs are not considered brainstem mediated responses and the presence of these responses does not exclude the diagnosis of brain death.

Which of the following is most likely to be decreased in a patient who has pulmonary edema? -PaO2 -Central venous pressure (CVP) -Vascular permeability -Pulmonary capillary wedge pressure -Hydrostatic pressure

PaO2. Discussion: Normal pulmonary physiology favors a small net influx of fluid from the alveolar capillaries into the lung interstitial space. The amount of fluid leaking from capillaries is dependent on the balance b/w hydrostatic and osmotic pressure. Pulmonary edema can occur d/t a cardiogenic etiology characterized by an increased hydrostatic pressure or noncardiogenic etiologies characterized by increased vascular permeability. In cardiogenic pulmonary edema, pulmonary capillary wedge pressure (PCWP), which is an estimate of left atrial filling pressure is increased. Cardiogenic pulmonary edema is also characterized by increased central venous pressure (CVP). References: 1. N Engl J Med. 2005 Dec 29;353(26):2788-96. 2. Crit Care Clin. 2015 Oct;31(4):803-21

Multiple endocrine neoplasia (type I) syndrome is characterized by tumors of the pituitary gland and the -Pancreas -Kidneys -Spinal column -Brainstem -Heart

Pancreas. MEN type I is a hereditary condition that leads to tumors of endocrine glands. The most common tumors are of the pituitary gland, pancreas, and parathyroid. The other lesions are not typically seen in this condition.

55M treated with abciximab is transferred to the emergency department with an intracerebral hematoma that requires immediate evacuation. Which of the following is the best strategy for management of this patient's coagulopathy? -IV administration of 5 mg vitamin K and proceed to the operating room -Perform platelet transfusion of 2000-2600 mL and proceed to the operating room -IV bolus administration of 800 mg andexanet alfa followed by infusion of 8mg/min for 120 minutes -IV administration of 250 mg aminophylline and proceed to the operating room -IV administration of 20mg methylprednisolone and proceed to the operating room

Perform platelet transfusion of 2000-2600 mL and proceed to the operating room Discussion: Abciximab binds to the glycoprotein (GP) IIb/IIIa receptor of human platelets and inhibits platelet aggregation. Thus, platelet administration would be the most effective strategy for treating the resulting coagulopathy. Steroids and aminophylline have no role in coaguloapthy reversal. Vitamin K would not be useful for coagulopathy resulting from platelet dysfunction. References: Medow JE, Dierks MR, Williams E, Zacko JC. The emergent reversal of coagulopathies encountered in neurosurgery and neurology: a technical note. Clin Med Res. 2015;13(1):20-31. doi:10.3121/cmr.2014.1237 Frontera JA, Lewin JJ 3rd, Rabinstein AA, Aisiku IP, Alexandrov AW, Cook AM, del Zoppo GJ, Kumar MA, Peerschke EI, Stiefel MF, Teitelbaum JS, Wartenberg KE, Zerfoss CL. Guideline for Reversal of Antithrombotics in Intracranial Hemorrhage: A Statement for Healthcare Professionals from the Neurocritical Care Society and Society of Critical Care Medicine. Neurocrit Care. 2016 Feb;24(1):6-46

25M brought to ED for L parasternal stab wound. Blood pressure is 70/50 mmHg, neck veins are distended, and heart sounds are muffled. Which of the following is the most likely diagnosis? -Pericardial tamponade -Disruption of sympathetic fibers -Vasovagal syncope -Pneumothorax -Acute blood loss anemia

Pericardial tamponade. The patient has shock related to this stab wound. Beck's triad of HoTN, elevated systemic venous pressure (neck vein distension), and muffled heart sounds is present & indicated of pericardial tamponade (a form of obstructive shock). Pneumothorax is possible, but decreased breath sounds would be a dominant feature. Hemorrhagic shock would not have distended neck veins, and shock related to SCI would not have these features.

Which of the following best characterizes Cheyne-Stokes respirations? -Sustained hyperventilation -Irregular, gasping respiration -Apnea -Periodic breathing with phases of hyperpnea alternating with apnea -Respiratory pause at full inspiration

Periodic breathing with phases of hyperpnea alternating with apnea. Cheyne-Stokes respiration is characterized by phases of hyperpnea alternating with apnea. Respiratory depth during the hyperpneic phase increases from breath to breath in a crescendo until a peak is reached followed by a decrescendo. A period of apnea follows which usually lasts 10-20 seconds. Cheyne-Stokes respiration is seen in metabolic encephalopathies and with lesions that impair forebrain and diencephalon function. Apnea occurs when lesions affect the ventral respiratory group in the ventrolateral medulla bilaterally. Irregular gasping breathing characterizes cluster or ataxic breathing, which is seen with lesions of the pontomedullary junction. A respiratory pause at full inspiration characterizes apneusis, which is seen with bilateral pontine lesions. Sustained hyperventilation is seen with metabolic encephalopathies and rarely in cases of high brainstem tumors.

The pressor effect of phenylephrine can be blocked by which of the following medications? -Diltiazem -Digoxin -Metoprolol -Phentolamine -Amiodarone

Phentolamine Discussion: IV Phenylephrine hydrochloride is a sympathomimetic amine that functions primarily as an alpha-1 adrenergic agonist. It is used for elevating mean arterial pressure by venous and arterial vasoconstriction and increasing cardiac preload without direct effect on the heart. Due to phenylephrine having only alpha-receptor stimulation, it can produce baroreceptor-mediated reflex bradycardia. Out of the options given, Phentolamine is the only medication that is a direct adrenergic alpha-receptor antagonist, which would counteract the effects of phenylephrine. References: Reference (1)Richards E, Lopez MJ, Maani CV. Phenylephrine. [Updated 2022 May 5]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan- Pubmed Web link https://www.ncbi.nlm.nih.gov/books/NBK534801/ Reference (2) Phentolamine. National Center for Biotechnology Information. PubChem Compound Database. Pubmed Web link https://pubchem.ncbi.nlm.nih.gov/compound/Phentolamine

Which of the following treatments is most likely to decrease the incidence of chronic subdural hematoma recurrence? -Induced hyponatremia -Irrigation of the subdural space -Hyperoxygen therapy -Placement of subdural drain -Bedrest with head of bed flat

Placement of subdural drain. In a randomized trial by Sartarius et al (2009), the placement of a SDD at the time of surgery decreased the incidence of symptomatic recurrence. All of the other methods have been utilized to try to decrease the incidence of recurrence after surgery. None has been shown to be effective in rigorous study. Newer techniques such as MMA embolization are currently being studied.

In the process of wound healing, which of the following cells arrives at the wound first? -Fibroblasts -Neutrophils -Macrophages -Platelets -Lymphocytes

Platelets Discussion: The wound healing process has three phases: the inflammatory phase, the proliferative phase, and the remodeling phase. The inflammatory phase is characterized by hemostasis, chemotaxis, and increased vascular permeability, limiting further damage, closing the wound, removing cellular debris and bacteria, and fostering cellular migration. The duration of the inflammatory stage usually lasts several days. Platelets migrate first, followed by neutrophils, then macrophages, then lymphocytes. Then, during the proliferative phase (beginning on approximately day 3), the most important cell is the fibroblast. The proliferative phase is characterized by the formation of granulation tissue, reepithelialization, and neovascularization. This phase can last several weeks. The maturation and remodeling phase is where the wound achieves maximum strength as it matures. References: Wallace HA, Basehore BM, Zito PM. Wound Healing Phases. [Updated 2022 Jun 21]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK470443/ Bowden LG, Byrne HM, Maini PK, Moulton DE. A morphoelastic model for dermal wound closure. Biomech Model Mechanobiol. 2016 Jun;15(3):663-81. Ninan N, Thomas S, Grohens Y. Wound healing in urology. Adv Drug Deliv Rev. 2015 Mar;82-83:93-105

Acute respiratory distress syndrome (ARDS) is the result of -Atelectasis -Pulmonary fibrosis -Diffuse alveolar hemorrhage -Pneumonia -Congestive heart disease

Pneumonia. Discussion: ARDS can result from direct or indirect lung injury. Pneumonia (bacterial, viral, fungal, or opportunistic) is the most common DIRECT lung-injury leading to ARDS. Aspiration of gastric contents, pulmonary contusions, inhalation injury, and near drowning can also lead to ARDS. Sepsis is the most common cause of INDIRECT lung-injury leading to ARDS. ARDS can also be caused by trauma or hemorrhagic shock, pancreatitis, burn injury, and blood product transfusion. After direct or indirect lung injury, lung alveolar macrophages are activated, leading to the release of potent proinflammatory mediators and chemokines promoting the accumulation of neutrophils and monocytes. This exudative phase of ARDS leads to alveolar and microvascular damage and loss of barrier function followed by alveolar flooding. Tumor necrosis factor (TNF) mediated expression of tissue factor promotes platelet aggregation and microthrombus formation, as well as intra-alveolar coagulation and hyaline membrane formation. The exudative phase is followed by a proliferative phase. After epithelial integrity has been reestablished, the reabsorption of alveolar edema in the provisional matrix restores alveolar architecture and function. A final fibrotic phase has been linked to prolonged mechanical ventilation and increased mortality. References: 1. N Engl J Med. 2017 Aug 10;377(6):562-572. 2. Crit Care. 2018 Oct 26;22(1):280.

48h s/p clipping of a HH3 ruptured aneurysm with intraoperative lumbar spinal drainage and lamina terminalis fenestration, a 56F becomes somnolent with pinpoint pupils and flexure posturing. Immediately after the procedure, she was oriented to person and place. CT scan shows small ventricles and crowding of the brain stem. Which of the following is the most appropriate initial step in management? -Position patient in Trendelenburg position -Insert a right frontal ventricular drain -Give mannitol 1g/kg IV over 30 minutes -Return to OR for decompressive craniotomy -Initiate HHH therapy

Position patient in Trendelenburg position. This pt is suffereing from central herniation syndrome d/t over-drainage of spinal fluid from the lumbar drain. The first step is to put the patient in reverse Trendelenburg position. A ventricular drain in this setting is used to treat non-communicating HCP which is unlikely considering that the ventricles are small and the lamina terminalis has been fenestrated. HHH therapy is used for the mgt of vasospasm. Brain swelling requiring mannitol or return to OR is in the differential but the patient is a bit early for severe vasospasm and a bit late for post-operative edema.

Postoperative hypocalcemia is most likely to have which of the following cardiovascular effects? -Torsades de pointed (polymorphic ventricular tachycardia) -Heart failure -Prolonged QT interval on EKG -Acute cardiac ischemia -HoTN

Prolonged QT interval on EKG. HoTN may complicate acute hypocalcemia, particularly when rapidly induced by transfusion of citrated blood or with use of low calcium dialysate in the patients undergoing renal replacement therapy. Heart failure has been reported in severe cases but is not the most common occurrence. Hypocalcemia characteristically causes prolongation of the QT interval on EKG. Hypocalcemia prolongs phase 2 of the action potential with the impact modulated by the rate of change of serum calcium concentration and function of the myocyte calcium channels. Torsades de pointes can be triggered by hypocalcemia but is much less common than with hypokalemia or hypomagnesemia.

Which of the following agents is most likely to partially reverse the effects of enoxaparin? -Tranexamic acid -Protamine -Platelets -FFP -4-factor PCC

Protamine. Heparinoids and their low molecular weight derivatives affect the clotting cascade by directly and indirectly affecting thrombin and factor X. Enoxaparin represents a commonly used low molecular weight heparin agent which is partially reversible. Protamine allows for reversal of 60-80% of the effects of enoxaparin.In order to reverse enoxaparin, it is important to note when the last dose of the medication was administered. If given within the prior 8 hours, 1mg of protamine must be administered per 1mg of enoxaparin over 10 minutes, with a maximum dose of 50mg of protamine. If the enoxaparin was given >8 hours prior, one can give ½ of the calculated protamine dose.

Which of the following pairs are the key factors that determine the total energy expenditure of spontaneous ventilation? -Alveolar surface area and diffusion -Ventilation and perfusion -Flow and PEEP -Pulmonary compliance and resistance -Alveolar-arterial gradient

Pulmonary compliance and resistance Discussion: Energy expenditure during breathing is directly related to work of breathing (WOB). Work is the product of pressure and volume. In respiratory physiology, WOB is typically associated with inspiraotry effort, as long as expiration remains a passive process. WOB can be determined by calculating the area under the curve of a pressure-volume plot. In this case, pressure is the sum of the transpulmonary pressure gradient and the chest wall pressure gradient. Alveolar surface area and diffusion are critical for gas exchange but not directly relevant to the work of breathing. The work to move air into and out of the lungs plus the work to expand the chest wall is the total work of breathing. Pulmonar compliance is directly related to WOB as it is the willingness of the lungs to distend described as the change in volume divided by change in pressure. Airway pressure during inflation is influenced by volume, thoracic compliance, and resistance to flow. Pressure gradients allow for flow to be generated, but this is not directly related to calculating WOB. Positive end expiratory pressure (PEEP) can be intrinsic or extrinsic. PEEP is an expiratory measurement and does not directly affect WOB. Ventilation and perfusion describe blood flow and airflow to the lungs but are not directly involved in WOB. The A-a graident measures the differencxe between oxygen concentration in the alveoli and arterial system. It is not directly related to WOB but is important in determining the diferential diagnosis for hypoxemia. References: 1. Magalhães, P., Padilha, G., Moraes, L. et al. Effects of pressure-support ventilation with different levels of positive end-expiratory in a mild model of acute respiratory distress syndrome. ICMx 3 (Suppl 1), A573 (2015). https://doi.org/10.1186/2197-425X-3-S1-

(Bank #4) Which of the following pairs are the key factors that determine the total energy expenditure of spontaneous ventilation? -Ventilation and perfusion -Flow and PEEP -Pulmonary compliance and resistance -Alveolar surface area and diffusion -Alveolar-arterial gradient

Pulmonary compliance and resistance. Energy expenditure during breathing is directly related to work of breathing (WOB). Work is the product of pressure and volume. In respiratory physiology, WOB is typically associated with inspiraotry effort, as long as expiration remains a passive process. WOB can be determined by calculating the area under the curve of a pressure-volume plot. In this case, pressure is the sum of the transpulmonary pressure gradient and the chest wall pressure gradient. Alveolar surface area and diffusion are critical for gas exchange but not directly relevant to the work of breathing. The work to move air into and out of the lungs plus the work to expand the chest wall is the total work of breathing. Pulmonar compliance is directly related to WOB as it is the willingness of the lungs to distend described as the change in volume divided by change in pressure. Airway pressure during inflation is influenced by volume, thoracic compliance, and resistance to flow. Pressure gradients allow for flow to be generated, but this is not directly related to calculating WOB. Positive end expiratory pressure (PEEP) can be intrinsic or extrinsic. PEEP is an expiratory measurement and does not directly affect WOB. Ventilation and perfusion describe blood flow and airflow to the lungs but are not directly involved in WOB. The A-a graident measures the differencxe between oxygen concentration in the alveoli and arterial system. It is not directly related to WOB but is important in determining the diferential diagnosis for hypoxemia. References: 1. Magalhães, P., Padilha, G., Moraes, L. et al. Effects of pressure-support ventilation with different levels of positive end-expiratory in a mild model of acute respiratory distress syndrome. ICMx 3 (Suppl 1), A573 (2015). https://doi.org/10.1186/2197-425X-3-S1-A573 2. Grinnan, D.C., Truwit, J.D. Clinical review: Respiratory mechanics in spontaneous and assisted ventilation. Crit Care 9, 472 (2005). https://doi.org/10.1186/cc3516

45F is admitted with a small R anterior temporal lobe contusion after an assault. Which of the following benefits do prophylactic anticonvulsants provide to this patient? -The use of prophylactic antiepileptics provide no benefit in this patient population -Reduce the risk of early post-traumatic seizures -Reduce the risk of post-traumatic epilepsy -Reduce the risk of late post-traumatic seizures -Reduce risk of status epilepticus in the first 24 hours following injury

Reduce the risk of early post-traumatic seizures Discussion: The prognosis following an acute symptomatic seizure, in the setting of stroke, traumatic brain injury (TBI) or Central Nervous System (CNS) infection, differs from that of a first unprovoked seizure. Patients with acute symptomatic seizures are 9 times more likely to die within 30 days, when compared to those with a first unprovoked seizure. Post-traumatic seizures are divided in 2 subgroups: early post-traumatic seizure (EPTS), when seizures occur within the first 7 days after brain injury, and late post-traumatic seizure (LPTS), when seizures occur after the first 7 days of injury. The use of antiepileptics drugs (AED) has been shown to reduce EPTS, but no benefits have been demonstrated for its use in LPTS. References: Reference (1)Kirmani BF, Robinson DM, Fonkem E, Graf K, Huang JH. Role of Anticonvulsants in the Management of Posttraumatic Epilepsy. Front Neurol. 2016 Mar 22;7:32. doi: 10.3389/fneur.2016.00032. PMID: 27047441; PMCID: PMC4801868. Pubmed Web link https://pubmed.ncbi.nlm.nih.gov/27047441/ Reference (2) Torbic H, Forni AA, Anger KE, Degrado JR, Greenwood BC. Use of antiepileptics for seizure prophylaxis after traumatic brain injury. Am J Health Syst Pharm. 2013 May 1;70(9):759-66. doi: 10.2146/ajhp120203. PMID: 23592358. Pubmed Web link https://pubmed.ncbi.nlm.nih.gov/23592358/ Reference (3) Hesdorffer DC, Benn EK, Cascino GD, Hauser WA. Is a first acute symptomatic seizure epilepsy? Mortality and risk for recurrent seizure. Epilepsia. 2009 May;50(5):1102-8. doi: 10.1111/j.1528-1167.2008.01945.x. Epub 2009 Jan 26. PMID: 19374657. Pubmed Web link https://pubmed.ncbi.nlm.nih.gov/19374657/

56M sustains severe TBI in a MVC. His ICP remains increased despite administration of hyperosmolar agents, CSF drainage, sedation, and paralysis. A pentobarbital coma is induced. Which of the following is a potential mechanism of neuroprotection from this intervention? -Increased blood flow -Activation of the GABA-B receptor -Reducing metabolic demand -Seizure prevention -Decreased CSF production

Reducing metabolic demand. When GABA binds to the GABA-A receptor on a neuron it causes opening of chloride channel that results in hyperpolarization and reduced synaptic firing. Barbiturates such as pentobarbital also bind to the GABA-A receptor, but at a different site than the GABA molecule itself. The effect of the barbiturate is to keep the chloride channel open longer, potentiating the inhibitory effect of the GABA molecule, a process referred to as allosteric modulation. In high doses, barbiturates result in a reduction in synaptic firing. As synaptic firing accounts for 50% of brain metabolism, barbiturates can significantly reduce metabolic demand. While barbiturates are used for seizure prophylaxis and treatment, seizure prevention is not a mechanism of neuroprotection. Barbiturates do not affect CSF production. Barbiturates do not bind to the GABA-B receptor. One criticism regarding the use of barbiturates for neuroprotection is their tendency to cause hypotension and reduced cerebral perfusion.

(Bank #2) Which of the following is the earliest sign of malignant hyperthermia? -Rising end-tidal CO2 -Hyperthermia -Metabolic acidosis -Muscle rigidity -Hyperkalemia

Rising end-tidal CO2. Discussion: Malignant hyperthermia (MH) is an autosomal dominate disorder associated with the ryodine receptor gene that can result in severe, potentially life-threatening complications with certain anesthetics. In individuals with a predisposition for MH, exposure to halogenated anesthetics (i.e. sevoflurane, halothane, enflurane, etc.) or succinylcholine (depolarizing paralytic) results in an uncontrolled release of calcium from skeletal muscle resulting in sustained muscle contraction. This results in a depletion of ATP and subsequent increase in O2 consumption and CO2 production. The earliest sign of MH is a rapid, unexplained rise in end-tidal CO2 associated with persistent tachycardia. Additional symptoms of MH include tachypnea, hypotension, rigidity, and fever. Laboratory evaluation may reveal anion gap metabolic acidosis, hyperkalemia, and hypercarbia. If left untreated, MH can result in cardiac dysrhythmias and cardiac arrest. The treatment for suspected MH is removal of the offending anesthetic agent, hyperventilation with 100% O2, and administration of dantrolene. Dantrolene is a muscle relaxant that acts by inhibiting the release of calcium from the sarcoplasmic reticulum of skeletal muscle. References: Watt S, McAllister RK. Malignant Hyperthermia. [Updated 2021 Jul 25]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK430828/ Adnet PJ, Gronert GA. Malignant hyperthermia: advances in diagnosis and management. Current Opinion, Anesthesiology. 1999; 12:353-358https://pubmed.ncbi.nlm.nih.gov/17013338/

42M w/ a head injury has clear nasal drainage. Which of the following is the most useful method to determine the nature of this fluid? -CT of the brain and sinuses -Observation over time -Send fluid for beta-2 transferrin -Lumbar puncture -Endoscopic evaluation

Send fluid for beta-2 transferrin. The patient's condition is c/f CSF leakage. The best method to differentiate CSF from normal discharge is beta-2 transferrin, which would be seen in CSF and not typical nasal fluid. Endoscopic evaluation, imaging, and observation would be suggestive but not diagnostic. Lumbar puncture would be useful to r/o meningitis.

Dysfunction of which part of the following hypothalamic-pituitary axes is most likely three to six months after aneurysmal subarachnoid hemorrhage? -Prolactin -Adrenal -Thyroid -Somatotroph -Gonadotroph

Somatotroph Discussion: Low pituitary gland volume has been shown to occur after SAH and may result from cell death or diminished cell size. This may contribute to SAH-mediated dysfunction of hormone-secreting cells in the anteiro pituitary gland. Hypopituitarism may occur in the acute and subacute phase after SAH in up to 49% of patients with 26% of patients experiencing chronic issues. Pituitary function, specifically growth-hormone deficiency, contributes to poor quality of life. Growth-hormone is likely to be the most commonly affexted axis in SAH patients. Due to the anatomical site with blood supply via the long hypophysial portal system, the somatotrophs are most vulnerable. Of note, somatotrophs are the predominant cell type of the anterior pituitary gland and account for about 45% of pituitary cells. References: 1. Can A, Gross BA, Smith TR, et al. Pituitary dysfunction after aneurysmal subarachnoid hemorrhage: a systematic review and meta-analysis. Neurosurgery. 2016;79:253-64. 2. Rass V, Schoenherr E, Ianosi BA, Lindner A, Kofler M, Schiefecker AJ, Lenhart L, Gaasch M, Pertl MT, Freyschlag CF, Pfausler B, Delazer M, Beer R, Thomé C, Grams AE, Scherfler C, Helbok R. Subarachnoid Hemorrhage is Followed by Pituitary Gland Volume Loss: A Volumetric MRI Observational Study. Neurocrit Care. 2020 Apr;32(2):492-501. doi: 10.1007/s12028-019-00764-x. PMID: 31222466; PMCID: PMC7082384

Which of the following molecular signals induces the development of the floor plate of the spinal cord and specifies the identity of motor neurons? -Notch -Retinoic Acid -Sonic Hedgehog -Fibroblast Growth Factor -Hippo

Sonic Hedgehog Discussion: The external ectoderm generates the epidermis, whereas the neural crest cells form the peripheral ganglion, the pigments of the skin, and the dorsal root ganglia. Finally, the neural tube gives rise to the Central Nervous System, composed of the brain and the spinal cord. Motor neurons are generated from a specific domain of ventral neural progenitors of the spinal cord. Progenitor domains are defined by graded Sonic Hedgehog (SHH) signaling regulating the combinatorial expression of transcription factors. SHH is expressed by the notochord and floor plate. Hippo signaling is an evolutionarily conserved pathway that controls organ size by regulating cell proliferation, apoptosis, and stem cell self-renewal. The Notch pathway mediates juxtacrine cellular signaling wherein both the signal sending and receiving cells are affected through ligand-receptor crosstalk, by which an array of cell fate decisions in neuronal, cardiac, immune, and endocrine development are regulated. References: Price SR, Briscoe J. The generation and diversification of spinal motor neurons: signals and responses. Mech Dev. 2004 Sep;121(9):1103-15. doi: 10.1016/j.mod.2004.04.019. PMID: 15296975. Blum JA, Klemm S, Shadrach JL, Guttenplan KA, Nakayama L, Kathiria A, Hoang analysis of the adult mouse spinal cord reveals molecular diversity of autonomic and skeletal motor neurons. Nat Neurosci. 2021 Apr;24(4):572-583. doi: 10.1038/s41593-020-00795-0. Epub 2021 Feb 15. PMID: 33589834; PMCID: PMC8016743.

Which of the following is the most likely explanation for demyelination in multiple sclerosis? -Developed of gray matter plaques -Increased vitamin D -Hyperactivity of the innate immune system -Increased sun exposure -T cell sensitization to a component of myelin

T cell sensitization to a component of the myelin is thought to trigger demyelination. Prominent components include myelin oligodendrocyte glycoprotein (MOG) and myelin basic protein (MBP). T cells have been demonstrated to initiate the MS plaques. MS plaques occur in the white matter. While both B and T cells are involved in the pathophysiology of MS, the innate immune system is not suspect to play a prominent role in the occurrence of demyelination. Vitamin D deficiency and decreased sun exposure are thought to contribute to MS and may help to explain why MS is more prominent in populations living at higher altitutes.

Which of the following is the initial fluid of choice for resuscitation of patients in septic shock? -LR -Concentrated 25% albumin -Pentastarch -Hydroxyethyl starch -Hypertonic saline

The ideal fluid of choice in the resuscitation of patients in septic shock is a isotonic solution, based on several clinical trials. There is increasing evidence that normal saline is associated with increased mortality and kidney injury; balanced isotonic crystalloids may be a safer alternative. Hyperosmolar solutions have been associated with worse outcomes. Administration of Albumin 5% can be considered, although controversial, with lesser clinical evidence. There is no evidence for the efficacy for concentrated Albumin 25%. Hydroxyethyl starches appear to increase mortality and kidney injury in the critically ill and are no longer indicated in these patients.

The Transfusion Requirments in Critical Care (TRICC) trial demonstrated that liberal transfusion (Hgb < 10) vs restrictive transfusion (Hgb 7) protocols are associated with which of the following outcomes in critically ill patients? -Higher rates of multi-organ failure in the restrictive-strategy transfusion group -Higher rates of multi-organ failure in the liberal-strategy transfusion group -The mortality rates during hospitalization were higher in the liberal transfusion group -Cardiac events (pulmonary edema, myocardial infarction) were more frequent in the restrictive-strategy transfusion group in patients in the ICU -The rate of death within 30 days of admission were similar between the liberal and restrictive-strategy transfusion groups

The rate of death within 30 days of admission were similar between the liberal and restrictive-strategy transfusion groups. Discussion: The primary outcome — the rate of death from all causes in the 30 days after admission to the intensive care unit — was 18.7 percent in the restrictive-strategy group and 23.3 percent in the liberal-strategy group (95 percent confidence interval for the difference between the groups, -0.84 percent to 10.2 percent; P=0.11) The mortality rates during hospitalization were lower in the restrictive-strategy group (22.2 percent vs. 28.1 percent, P=0.05). Other mortality rates including the mortality rate during the entire stay in the intensive care unit (13.9 percent vs. 16.2 percent, P=0.29) and the 60-day mortality rate (22.7 percent vs. 26.5 percent, P=0.23) were also lower in the restrictive-strategy group but not significantly so.The number of patients with multiorgan failure (more than three organs), which was analyzed as a dichotomous variable (present or absent) for each of seven organ systems,18 was not significantly different between the restrictive-strategy and liberal-strategy groups (5.3 percent vs. 4.3 percent, P=0.36).Cardiac events, primarily pulmonary edema and myocardial infarction, were more frequent in the liberal-strategy group than in the restrictive-strategy group during the stay in the intensive care unit (P<0.01).The mortality rates during hospitalization were lower in the restrictive-strategy group (22.2 percent vs. 28.1 percent, P=0.05). References: Hébert PC, Wells G, Blajchman MA, Marshall J, Martin C, Pagliarello G, Tweeddale M, Schweitzer I, Yetisir E. A multicenter, randomized, controlled clinical trial of transfusion requirements in critical care. Transfusion Requirements in Critical Care Investigators, Canadian Critical Care Trials Group. N Engl J

According to the Brain Trauma Foundation Guidelines for the Management of Severe Traumatic Brain Injury, level I evidence exists for which of the following statements? -Feeding patients to attain basal caloric replacement by the fifth day is recommended to decrease mortality -Prolonged prophylactic hyperventilation is not recommended -Treating ICP above 22 mmHg is recommended to decrease mortality -Continuous drainage of CSF through an external ventricular drain may be considered to lower intracranial pressure (ICP) -Use of steroids is not recommended for improving outcome or reducing ICP

Use of steroids is not recommended for improving outcome or reducing ICP Discussion: Continuous drainage of CSF through an external ventricular drain is a level 3 recommendation in the updated brain trauma foundation guidelines, whereas feeding patients to attain basal caloric replacement by the fifth day is level 2a, and prolonged prophylactic hyperventilation and treating ICP above 22 mmHg are level 2b. The only level I evidence is to avoid the use of steroids in the treatment of traumatic brain injury in the Brain Trauma Foundation Guidelines for the Management of Severe Traumatic Brain Injury. References: Carney N, Totten AM, O'Reilly C, Ullman JS, Hawryluk GW, Bell MJ, Bratton SL, Chesnut R, Harris OA, Kissoon N, Rubiano AM, Shutter L, Tasker RC, Vavilala MS, Wilberger J, Wright DW, Ghajar J. Guidelines for the Management of Severe Traumatic Brain Injury, Fourth Edition. Neurosurgery. 2017;80(1):6-15 The Brain Trauma Foundation. The American Association of Neurological Surgeons. The Joint Section on Neurotrauma and Critical Care. Role of steroids. J Neurotrauma. 2000 Jun-Jul;17(6-7):531-5.

(Bank #1) Severe hypomagnesemia is most likely to produce which of the following? -Hyperkalemia -Hypotension -Ventricular arrhythmias -Hypoactive reflexes -Hypercalcemia

Ventricular arrhythmias. Discussion: Mg prevents increases in action potential duration and prolongation of membrane repolarization. These changes commonly occur after myocardial ischemia and can lead to ventricular arrhythmias. A-Fib can also be provoked by hypoMg. Magnesium causes presynaptic inhibition leading to a depressant effect on the CNS. HypoMg results in renal potassium loss and also suppresses PTH hormone release and activity. HypoMg therefore often occurs in conjunction w/hypokalemia & hypocalcemia. HypoMg can be associated w/HTN rather than HoTN. References: 1. Agus MS, Agus ZS. Cardiovascular actions of magnesium. Crit Care Clin. 2001 Jan;17(1):175-86. 2. Handb Clin Neurol. 2017;141:705-713.

Which of the following is an antioxidant required for collagen synthesis and wound healing? -Glutathione -Vitamin E -N-acetylcysteine -Vitamin C -Coenzyme Q10

Vitamin C Discussion: Healing of tissues such as bone, tendon, and ligament requires collagen synthesis. Vitamin C (ascorbic acid) has an important role in connective tissue healing as it is a cofactor for prolyl hydroxylase and lysyl hydroxylase. These enzymes catalzye the hydroxylation of proline and lysine amino acid residues within procollagen, subsequently promoting proper folding and stability of the stable collagen triple helix formation. Vitamin C is also an antioxidant that is able to neutralize reactive oxygen species. References: 1. DePhillipo NN, Aman ZS, Kennedy MI, Begley JP, Moatshe G, LaPrade RF. Efficacy of Vitamin C Supplementation on Collagen Synthesis and Oxidative Stress After Musculoskeletal Injuries: A Systematic Review. Orthop J Sports Med. 2018 Oct 25;6(10):2325967118804544. doi: 10.1177/2325967118804544. PMID: 30386805; PMCID: PMC6204628 2. Gref, R., Deloménie, C., Maksimenko, A. et al. Vitamin C-squalene bioconjugate promotes epidermal thickening and collagen production in human skin. Sci Rep 10, 16883 (2020). https://doi.org/10.1038/s41598-020-72704-1.

40F sustained an AComm aneurysm rupture 48h ago. She now has Na 130. Assessment of which of the following parameters is most appropriate before correction with an infusion of 100 mL/hr of sodium chloride 0.9%? -Urine Na -Fractional excretion of uric acid -Serum Osm -Volume status -Urine Osm

Volume status. The initial evaluation of hypoNa is to distinguish true hypoosmolar hypoNa from translocational hypoNa (mannitol, hyperglycemia, uremia, ethanol) or pseudohyponatremia (eg hyperproteinemia, dyslipidemia) via SOsm. A normal or elevated SOsm suggests either translocational hyponatremia or pseudohypoNa. Both CSW and SIADH are d/t abnormal water or sodium excretion, and therefore do not have inappropriately high urine osmolality. However, both SIADH and CSW have elevated urine sodium, and therefore, cannot be distinguished based on this finding alone. SIADH and CSW are differentiated by volume status. SIADH is associated with a euvolemic or slightly hypervolemic state, whereas CSW results in a hypovolemic state. Fractional excretion of uric acid (FeUA) may have some clinical utility. Initially, FeUA is elevated (> 10) in both CSW and SIADH. With normalization of sodium, FeUA corrects in SIADH, however remains elevated in CSW. Until significant hypovolemia develops, patients with CSW tend to have higher urine volumes and high 24 hour urinary excretion of sodium. Alternatively in SIADH, urine volume is normal to low, and therefore sodium excretion is also normal to low. As distinguishing mild hypovolemia from euvolemia is challenging, this feature may have greater practical use at the bedside.