Anesthesia question of the day
The rhythm strip below is indicative of: A. First degree block B. Second degree block, type I C. Second degree block, type II D. Bifascicular block
Answer: B. Second degree block, type I (Wenckebach) Second degree block, type I, shows progressive lengthening of the PR interval with each cycle until a QRS complex is dropped. This type of block indicates AV nodal disease and associated bradycardia usually responds to the administration of atropine. Page 1704 Barash, Clinical Anesthesia
Disodium edetate or sodium metabisulfite is added to formulations of propofol to: A. Enhance drug solubility B. Adjust pH C. Inhibit bacterial growth D. Increase drug potency
Answer: C. Inhibit bacterial growth Current formulations of propofol contain 0.005% disodium edetate or 0.025% sodium metabisulfite to help retard the rate of microorganism growth. Page 186 Morgan & Mikhail's Clinical Anesthesiology
The highest incidence of muscle pain following the use of succinylcholine is seen in : A. Infants B. Octogenarians C. Outpatients D. Pregnant patients
Answer: C. Outpatients Myalgia following the use of succinylcholine is most commonly seen in females and outpatients. Pregnancy and extremes of ages seem to be protective. Page 532 Barash, clinical Anesthesia
During hip replacement surgery, cardiopulmonary changes associated with acrylic bone cement includes: A-hypotension secondary to cement monomer absorption B- Hypoxemia secondary to air embolization C-Hypoxemia secondary to fat embolization D-Hypocarbia E-Decreased pulmonary artery pressure F-Increased end-tidal carbon dioxide
A-Hypotension secondary to cement monomer absorption B-Hypoxemia secondary to air embolization C-Hypoxemia secondary to fat embolization During hip replacement surgery, hypotension with the use acrylic bone cement has been attributed to absorption of methyl methacrylate monomer, embolization of air and bone marrow and conversion of Methyl methacrylate to methacrylic acid. Hypoxemia is common. Embolic event cause an increase in dead space with a reduction in ETCO2 with an increase in PaCO2. Page 1454 Barash, Clinical Anesthesia.
In the pressure-volume loop below, cardiac work is best represented by: A. The area of the curve B. The slope of the line from points C to D C. The distance of the line form points C to D D. The slope of a line from points A to D
A. The area of the curve Cardiac work is the product of pressure and volume and is linearly related to myocardial oxygen consumption. Cardiac work is best represented by the area of the curve of a pressure-volume loop. Pg. 250 Barash, PG, Cullen, Clinical Anesthesia
39. Disodium edetate or sodium metabisulfite is added to formulations of propofol to: A) enhance drug solubility B) increase drug potency C) adjust pH D) inhibit bacterial growth
Answer: D) inhibit bacterial growth Current formulations of propofol contain 0.005% disodium edetate or 0.025% sodium metabisulfite to help retard the rate of microorganism growth
48. Anesthetic implications of multiple sclerosis include: A) exacerbation induced by spinal anesthesia B) exacerbation of symptoms secondary to hypothermia C) exacerbation induced by epidural anesthesia d) all of the above
Answer: A) exacerbation induced by spinal anesthesia Spinal anesthesia has been reported to cause exacerbation of the disease. Epidural and other regional techniques appear to have no adverse effect, especially in obstetrics. Demyelinated nerve fibers are extremely sensitive to hyperthermia, but conduction is usually improved by mild hypothermia.
Identify the following rhythm strip:
Answer: 1st Degree AV Block 1st Degree AV block is caused by a conduction delay through the AV node but all electrical signals reach the ventricles. This rarely causes any problems by itself and often trained athletes can be seen to have it. The normal P-R interval is between 0.12s to 0.20s in length, or 3-5 small squares on the ECG. Looking at the ECG you'll see that: • Rhythm - Regular • Rate - Normal • QRS Duration - Normal • P Wave - Ratio 1:1 • P Wave rate - Normal • P-R Interval - Prolonged (>5 small squares)
12. A 42-year-old man is undergoing a thoracoscopy. During the procedure an 8-minute period of apneic oxygenation is required. If the patient's PaCO2 is 40 mmHg, the expected PaCO2 at the end of the apneic period would be: (Enter numerical answer on the line below.) ______ mmHg
Answer: 67 to 74 mmHg The apneic oxygenation technique affords adequate oxygen delivery, but progressive respiratory acidosis limits the use of this technique to 10 - 20 minutes in most patients. Arterial PaCO2 rises 6 mmHg in the first minute followed by a rise of 3 - 4 mmHg during each subsequent minute. In this patient this will produce a 27 - 34 mmHg increase, resulting in a PaCO2 of 67 to 74 mmHg.
21. Pulmonary changes associated with Duchenne's muscular dystrophy include: A) a restrictive ventilatory defect B) increased residual volume C) an obstructive ventilatory defect D) decreased pulmonary artery pressures
Answer: A) a restrictive ventilatory defect The combination of marked kyphoscoliosis and degeneration of the respiratory muscles produces a severe restrictive ventilatory defect in patients with Duchenne's muscular dystrophy. Pulmonary hypertension is also commonly seen
8. Neuroleptic malignant syndrome: A) can be precipitated with the use of metoclopramide B) can be diagnosed with muscle biopsy C) carries a mortality of over 80% D) can be treated with physostigmine administration
Answer: A) can be precipitated with the use of metoclopramide Neuroleptic malignant syndrome is a rare complication of antipsychotic therapy. Meperidine and metoclopramide can also precipitate the disorder which appears to be secondary to dopamine blockade in the basal ganglia. The disease has many characteristics in common with MH including increased temperature, metabolic derangement and hyperthermia. The mortality is 20 - 30%. Treatment with dantrolene and dopamine agonist, bromocripitine, appears effective.
32. Examples of Type IV hypersensitivity reactions include: A) contact dermatitis B) angioedema C) hemolytic transfusion reactions D) anaphylaxis
Answer: A) contact dermatitis Type IV hypersensitivity reactions are delayed and cell-mediated. Examples of Type IV reactions include contact dermatitis, tuberculin-type hypersensitivity and chronic hypersensitivity pneumonitis.
19. The most significant preoperative cardiac risk factor is: A) evidence of congestive heart failure B) uncontrolled hypertension C) renal failure D) presence of pathological Q waves
Answer: A) evidence of congestive heart failure The two most important preoperative cardiac risk factors are evidence of CHF and unstable coronary syndrome
An increase in the plasma concentration and a prolongation of the elimination half-life of etomidate is seen with the concomitant administration of: A. Midazolam B. Roruconium C. Fentanyl D. Succinylcholine
Answer: C. Fentanyl Fentanyl has been shown to increase the plasma level of etomidate as well as prolong the elimination half-life of the drug. Page 185 Morgan & Mikhail's Clinical Anesthesiology.
43. Correct statements concerning the use of benzodiazepines in the elderly include: A) volume of distribution is increased B) the elimination half-life of diazepam, but not midazolam, is increased C) reduced pharmacodynamic sensitivity is observed d) all of the above
Answer: A) volume of distribution is increased Aging increases the volume of distribution for all benzodiazepines, effectively prolonging their elimination half-lives. Enhanced pharmacodynamic sensitivity is also observed. The elimination half-lives of both diazepam and midazolam are increased
Example of type IV hypersensitivity reactions include: A. Contact dermatitis B. Hemolytic transfusion reactions C. Anaphylaxis D. Angioedema
Answer: A. Contact dermatitis Type IV hypersensitivity reactions are delayed and cell-mediated. Examples of Type IV reactions include contact dermatitis, tuberculin-type hypersensitivity and chronic hypersensitivity pneumonitis Page 292 Barash, Clinical Anesthesia.
Local anesthetics with the potential to form methemoglobin include: (select 3): A. EMLA topical anesthetic cream B. Bupivacaine C. Benzocaine D. Ropivacaine E. Prilocaine F. Mepivacaine
Answer: A. EMLA topical anesthetic cream C. Benzocaine E. Prilocaine EMLA cream contains both lidocaine and prilocaine. The metabolites of prilocaine can convert hemoglobin to methemoglobin. Benzocaine can also cause methemoglobinemia. Page 140 Nagelhout, Nurse Anesthesia
Anesthetic implications of multiple sclerosis include: A. Exacerbation induced by spinal anesthesia B. Exacerbation induced by epidural anesthesia C. Exacerbation of symptoms secondary to hypothermia D. All of the above
Answer: A. Exacerbation induced by spinal anesthesia Spinal anesthesia has been reported to cause exacerbation of the disease. Epidural and other regional techniques appear to have no adverse effect, especially in obstetrics; however a lower concentration of local anesthetic should be used. Demyelinated nerve fibers are extremely sensitive to hyperthermia, but conduction is usually improved by mild hypothermia
Absolute contraindications to the use of epidural anesthesia in the parturient include (select 2): A. Inability of the patient to cooperate B. Herniated lumbar disc C. Multiple sclerosis D. Patient refusal E. History of previous cesarean section F. Aortic regurgitation
Answer: A. Inability of the patient to cooperate D. Patient refusal Absolute contraindication to epidural anesthesia/analgesia in the parturient include infection over the injection site, coagulopathy, thrombocytopenia, marked hypovolemia, true local anesthetics allergy, patient refusal and inability of the patient to cooperate. Preexisting neurological disease and back disorders are relative contraindications. Patients with Aortic regurgitation usually benefit from the reduction in afterload seen after neuraxial anesthesia. Page 849 Morgan & Mikhail's Clinical Anesthesiology
A nonselective Alpha antagonist used in the preoperative preparation of a patient with pheochromocytoma is: A. Phenoxybenzamine B. Doxazosin C. Propranolol D. Terazosin
Answer: A. Phenoxybenzamine (Dibenzyline) Phenoxybenzamine is a non-selective alpha antagonist used in the preoperative preparation of the patient with pheochromocytoma. Doxazosin and Terazosin are selective alpha1 antagonists. Propranolol is nonselective beta blockade. In the preparation of patients with pheochromocytoma, alpha blockade and intravascular volume replacement must precede beta-blockade, so as to prevent the possibility of unopposed alpha stimulation. Page 192 Nagelhout, JJ
Physiologic derangements seen in the patient with scleroderma include (select 3): A. Pulmonary hypertension B. Esophageal dysmotility C. Excessive oral secretions and salivation D. Myocardial fibrosis E. Hypotension F. Spastic quadraparesis
Answer: A. Pulmonary hypertension B. Esophageal dysmotility D. Myocardial fibrosis Scleroderma is an autoimmune disease with multi-organ involvement. It is characterized by excessive deposition of collagen and subsequent fibrosis of the skin and internal organs. Manifestations are most evident in the skin, but pulmonary, cardiac, vascular and renal involvement may also be present. Patients with scleroderma are frequently difficult intubations and are at high risk for aspiration. Systemic hypertension form renal disease is very common. Xerostomia and decreased lacrimation are a result of exocrine gland involvement. Page 636, Barash, PG, Clinical Anesthesia. Per Mayo clinic: Scleroderma is a group of rare, progressive diseases that involve the hardening and tightening of the skin and connective tissues. The fibers that provide the framework and support for your body. Localized scleroderma affects only the skin. Systemic scleroderma also harms internal organs, such as the heart, lungs, kidneys and digestive tracts
Correct statements concerning the use of benzodiazepines in the elderly include: A. Volume of distribution is increased B. Reduced pharmacodynamics sensitivity is observed C. The elimination half-life of diazepam, but not midazolam, is increased D. All of the above
Answer: A. Volume of distribution is increased Aging increases the volume of distribution for all benzodiazepines, effectively prolonging their elimination half-lives. Enhanced pharmacodynamics sensitivity is also observed. The elimination half-lives of both diazepam and midazolam are increased. Page 895, Barash, Clinical Anesthesia
The rhythm strip below is indicative of:
Answer: Atrial Fibrillation Many sites within the atria are generating their own electrical impulses, leading to irregular conduction of impulses to the ventricles that generate the heartbeat. This irregular rhythm can be felt when palpating a pulse It may cause no symptoms, but it is often associated with palpitations, fainting, chest pain, or congestive heart failure. Looking at the ECG you'll see that: • Rhythm - Irregularly irregular • Rate - usually 100-160 beats per minute but slower if on medication • QRS Duration - Usually normal • P Wave - Not distinguishable as the atria are firing off all over • P-R Interval - Not measurable • The atria fire electrical impulses in an irregular fashion causing irregular heart rhythm
Identify the following rhythm strip:
Answer: Atrial Flutter Looking at the ECG you'll see that: • Rhythm - Regular • Rate - Around 110 beats per minute • QRS Duration - Usually normal • P Wave - Replaced with multiple F (flutter) waves, usually at a ratio of 2:1 (2F - 1QRS) but sometimes 3:1 • P Wave rate - 300 beats per minute • P-R Interval - Not measurable • As with SVT the abnormal tissue generating the rapid heart rate is also in the atria, however, the atrioventricular node is not involved in this case.
40. During emergent transtracheal jet ventilation using a 14 gauge catheter, generation of sufficient gas flow requires a driving pressure of: A) 20 cmH2O B) 50 psi C) 50 cmH2O D) 25 psi
Answer: B) 50 psi After proper location of the catheter is confirmed by aspiration air, jet ventilation may be achieved with intermittent pulses of oxygen at 50 psi.
37. Bone marrow depression and peripheral neuropathy have been associated with prolonged exposure to anesthetic concentrations of: A) Isoflurane B) Nitrous oxide C) Desflurane D) Sevoflurane
Answer: B) Nitrous oxide By irreversibly oxidizing the cobalt atom in vitamin B12, nitrous oxide inhibits vitamin B12 dependent enzymes. These enzymes include methionine synthetase and thymidylate synthetase. As a result of these enzyme inhibitions, prolonged exposure to nitrous oxide has been associated with bone marrow depression, megaloblastic anemia, peripheral neuropathy and teratogenicity.
1. Effects of lidocaine include: A) increased intracranial pressure B) lytic degeneration, edema and necrosis of skeletal muscle C) increased refractory period of cardiac muscle D) decreased fibrinolysis
Answer: B) lytic degeneration, edema and necrosis of skeletal muscle Intravenous lidocaine decreases cerebral blood flow unless seizure activity develops. Lidocaine decreases the refractory period of cardiac muscle and decreases platelet aggregation while enhancing fibrinolysis. Local anesthetics have been shown to cause lytic degeneration and necrosis of muscle fibers when directly injected into the muscle (trigger point injections)
3. The dibucaine number: A) is normally less than 60% B) reflects inhibition of pseudocholinesterase by dibucaine C) is a quantitative assessment of pseudocholinesterase activity D) is inversely proportional to pseudocholinesterase function
Answer: B) reflects inhibition of pseudocholinesterase by dibucaine Dibucaine, a local anesthetic, inhibits normal pseudocholinesterase. Homozygous patients with abnormal pseudocholinesterase characteristically have a dibucaine number of about 20%, heterozygous patients have numbers of 40 - 60% and normal patients usually have a dibucaine number of 80%. The dibucaine number is proportional to pseudocholinesterase function, but is independent of the amount of the enzyme.
The highest rate of systemic absorption of local anesthetic is seen with: A- Epidural injection B- Intercostal injection C- Caudal injection D- Brachial plexus injection
Answer: B- Intercostal injection The rate of systemic absorption of local anesthetic is proportionate to the vascularity of the site of injection: intravenous> tracheal> intercostal>caudal>paracervical>epidural>brachial plexus>subcutaneous. Page 569 Barash, Clinical Anesthesia
Average blood loss during a vaginal delivery is: A. 100-200ml B. 400-500ml C. 700-800ml D. 1000-1500ml
Answer: B. 400-500ml At term, blood volume has increased by 1000-1500 ml in most women allowing them to easily tolerate the blood loss associated with delivery. Average blood loss during vaginal delivery is 400-500ml, compared with 800-1000 ml for cesarean section. Page 827 Morgan & Mikhail's Clinical Anesthesiology.
The maximum recommended occupational whole body exposure to radiation is: A. 1 rem/year B. 5 rem/year C. 10 rem/year D. 20 rem/year
Answer: B. 5 rem/year The intraoperative use of imaging equipment exposes anesthesia providers to ionizing radiation. The maximum recommended whole-body exposure to radiation is 5 rem/year. The United states unit of measurement for radiation dose is the rem (Roentgen Equivalent Man). Most other countries measure radiation dose using the metric system unit of Sieverts (Sv). 1000 mrem=1rem 1mSv=100 millrems 1000mSv= 1Sv Page 65 Barash, Clinical Anesthesia.
Basal metabolic oxygen consumption in a 20 kg patient is approximately: A. 50ml/min B. 95ml/min C. 150ml/min D. 250ml/min
Answer: B. 95ml/min Basal metabolic oxygen consumption can be estimated using the following formula: V02 = 10 Kg^3/4
Concerning preoperative informed consent: A. It should disclose only life-threatening complications B. Charges of assault and battery are possible of it is not obtained C. Oral consent is sufficient D. It is not necessary if the procedure is done in an office setting
Answer: B. Charges of assault and battery are possible of it is not obtained Any procedure performed without the patient's consent can constitute assault and battery. Oral consent may be sufficient, but written consent is advisable for medicolegal purposes. It is generally accepted that not all risks need to be detailed, but risks that are realistic and have resulted in complications in similar patients should be disclosed. PP 29-30 Nagelhout Nurse Anesthesia.
Current anesthesia apparatus checkout recommendations suggest which of the following prior to every case? A. Check oxygen cylinder supply B. Check the carbon dioxide absorber C. Performance of a machine low-pressure leak test D. Calibration of the oxygen monitor
Answer: B. Check the carbon dioxide absorber Verification of the adequacy of the carbon dioxide absorber s suggested prior to every case. If the same anesthesia machine is being used by the same provide, E-cylinder pressure checks, machine low-pressure leak testing and calibration of the oxygen sensor need not be repeated after an initial check. PP 84-85 Morgan & Mikhail's Clinical Anesthesiology.
Nerves blocked with a fascia iliaca block include the: A. Sciatic nerve B. Femoral nerve C. Pudendal nerve D. Anterior tibial nerve
Answer: B. Femoral nerve The fascia iliaca block utilizes a deposition of local anesthetic in the fascia iliaca compartment to block the femoral, lateral femoral cutaneous, obturator and genitofemoral nerves. PP 1003-1004 Morgan & Mikhails Clinical Anesthesiology
The addition of bicarbonate to a local anesthetic solution: A. Delays the onset of blockade B. Increases the concentration of the nonionic form of the local anesthetic C. Causes a fall in eth pH of the solution D. Should only be done when using bupivacaine
Answer: B. Increases the concentration of the nonionic form of the local anesthetic The onset of neural blockade depends on eth penetration of the nerve cell membrane by the nonionic form of the anesthetic. Increasing the pH of the anesthetic solution increases the concentration of the nonionic form and thereby hastens the onset of the block. Bicarbonate is usually not added to bupivacaine, since it can cause precipitation if the pH is raised above 6.8 Page 963 Morgan & Mikhail's Clinical Anesthesiology
Topically applied ophthalmic medications are absorbed: A. As quickly as intravenous administration B. More quickly than subcutaneous administration C. Only minutely, with insignificant clinical effect D. Directly into the central nervous system through the optic nerve foramen
Answer: B. More quickly than subcutaneous administration Topically applied ophthalmic medications are absorbed at a rate intermediate between intravenous and subcutaneous injection. Children and the elderly are at particular risk for the toxic effects of topically applied medications. Page 762 Morgan & Mikhail's Clinical Anesthesiology.
An increase in intraocular pressure has been associated with: (select 3) A. Nitrous oxide administration B. Succinylcholine administration C. Opioid administration D. Hyperventilation E. Laryngoscopy F. Hypoxemia G. Sevoflurane administration
Answer: B. Succinylcholine administration E. Laryngoscopy F. Hypoxemia An increase in IOP (intraocular pressure) has been associated with: succinylcholine administration, hypoxemia, and laryngoscopy Succinylcholine increased intraocular pressure by 5-10 mmHg for 5 to 5 minutes after administration. This increase is primarily the result of prolonged contracture of the extrocular muscles from the depolarizing effects of succinylcholine. Nitrous oxide, volatile anesthetics agents and opioids have been associated with a reduction in intraocular pressure. Hypoxemia, Hypercarbia, hypertension, hypervolemia, laryngoscopy and intubation have all been shown to increase IOP. Pp 760-761 Morgan $ Mikhail's Clinical Anesthesiology
31. Average blood loss during a vaginal delivery is: A) 100 - 200 mL B) 1000 - 1500 mL C) 400 - 500 mL D) 700 - 800 mL
Answer: C) 400 - 500 ml At term, blood volume has increased by 1000 - 1500 ml in most women allowing them to easily tolerate the blood loss associated with delivery. Average blood loss during vaginal delivery is 400 - 500 ml, compared with 800 - 1000 ml for cesarean section.
25. According to the Modified Glasgow Coma Scale, a moderate head injury is associated with a score of: A) 13 - 15 B) Less than 6 C) 9 - 12 D) 6 - 9
Answer: C) 9 - 12 According to the Modified Glasgow Coma scale, mild head injury is associated with a score of 13 - 15, moderate head injury is associated with a score of 9 - 12, and severe head injury is associated with a score of less than 8.
36. Basal metabolic oxygen consumption in a 20 kg patient is approximately: A) 50 ml/min B) 250 ml/min C) 95 ml/min D) 150 ml/min
Answer: C) 95 ml/min Basal metabolic oxygen consumption can be estimated using the following formula: VO2 = 10Kg3/4
24. Current anesthesia apparatus checkout recommendations suggest which of the following prior to every case? A) Check oxygen cylinder supply B) Calibration of the oxygen monitor C) Check the carbon dioxide absorber D) Performance of a machine low-pressure leak test
Answer: C) Check the carbon dioxide absorber Verification of the adequacy of the carbon dioxide absorber is suggested prior to every case. If the same anesthesia machine is being used by the same provider, E-cylinder pressure checks, machine low-pressure leak testing and calibration of the oxygen sensor need not be repeated after an initial check.
2. Correct statements concerning the use of antidepressants in pain management include: A) analgesic effects require a higher dose than that needed for antidepression B) newer SSRIs are more effective analgesics than the older tricyclic antidepressants C) analgesic effects appear to be secondary to the blockade of serotonin and norepinephrine reuptake D) antidepressants are not effective in neuropathic pain
Answer: C) analgesic effects appear to be secondary to the blockade of serotonin and norepinephrine reuptake Antidepressants demonstrate an analgesic effect at doses lower that those needed for antidepressant effect. Both actions appear secondary to the block of the reuptake of serotonin and norepinephrine. Older tricyclic antidepressants seem more effective analgesics than the newer SSRIs. Antidepressants are most useful in patients with neuropathic pain.
11. The largest fraction of carbon dioxide in the blood is in the form of: A) carbamino compounds B) carboxyhemoglobin C) bicarbonate D) dissolved gas
Answer: C) bicarbonate Nearly 90% of carbon dioxide in the blood is in the form of bicarbonate.
44. Concerning preoperative informed consent: A) it should disclose only life-threatening complications B) it is not necessary if the procedure is done in an office setting C) charges of assault and battery are possible if it is not obtained D) oral consent is insufficient
Answer: C) charges of assault and battery are possible if it is not obtained Any procedure performed without the patient's consent can constitute assault and battery. Oral consent may be sufficient, but written consent is advisable for medicolegal purposes. It is generally accepted that not all risks need to be detailed, but risks that are realistic and have resulted in complications in similar patients should be disclosed.
30. Nerves blocked with a fascia iliaca block include the: A) sciatic nerve B) anterior tibial nerve C) femoral nerve D) pudendal nerves
Answer: C) femoral nerve The fascia iliaca block utilizes a deposition of local anesthetic in the fascia iliaca compartment to block the femoral, lateral femoral cutaneous, obturator and genitofemoral nerves.
26. The addition of bicarbonate to a local anesthetic solution: A) delays the onset of blockade B) should only be done when using bupivacaine C) increases the concentration of the nonionic form of the local anesthetic D) causes a fall in the pH of the solution
Answer: C) increases the concentration of the nonionic form of the local anesthetic The onset of neural blockade depends on the penetration of the nerve cell membrane by the nonionic form of the anesthetic. Increasing the pH of the anesthetic solution increases the concentration of the nonionic form and thereby hastens the onset of the block. Bicarbonate is usually not added to bupivacaine, since it can cause precipitation if the pH is raised above 6.8.
The National Institute of Occupational Safety (NIOSH) recommends limiting the operating room concentration of nitrous oxide to: A. 0.5 ppm B. 5 ppm C. 25 ppm D. 50 ppm
Answer: C. 25 ppm NIOSH recommends limiting the room concentration of nitrous oxide to 25 ppm and halogenated agents to 2ppm (0.5 ppm if nitrous oxide is also being used). Page 652-654, Longnecker, Newman . Anesthesiology.
A 24 year old female is scheduled for resection of a cerebral aneurysm. She has no other significant past medical history. Acceptable levels of hypotension would include a mean arterial pressure of: A. 20-30 mmHg B. 35-45 mmHg C. 50-60mmHg D. 90-100mmHg
Answer: C. 50-60mmHg Healthy young individual tolerate mean arterial pressures as low as 50-60mmHg without complications. Chronically hypertensive patients have altered auto regulation of cerebral blood flow and may tolerate a mean arterial pressure of no more that 20-30% below baseline. Page 262 Morgan & Mikhail's Clinical Anesthesiology.
During pregnancy, the minimum alveolar concentration (MAC): A. Decreases until the 20th week B. Increases until the 20th week C. Decreases throughout the pregnancy D. Increases throughout the pregnancy
Answer: C. Decreases throughout the pregnancy D. Increases throughout the pregnancy The MAC progressively decreases during pregnancy, at term by as much as 40%. MAC returns to normal by the third day after delivery. Page 826 Morgan & Mikhail's Clinical Anesthesiolog.
Sensory innervation of the trachea and larynx below the vocal cord is supplied by the: A. Internal laryngeal nerve B. External laryngeal nerve C. Recurrent laryngeal nerve D. Glossopharyngeal nerve
Answer: C. Recurrent laryngeal nerve The vagus nerve provides sensation to the airway below the epiglottis. The superior laryngeal branch of the vagus divides into an external (motor) and internal (sensory) laryngeal nerve that provide sensory supply to the larynx between the epiglottis and the vocal cords. Another branch of the vagus, the recurrent laryngeal nerve, innervates the larynx below the vocal cords and the trachea. Page 310 Morgan & Mikhail Clinical Anesthesiology
While performing a nerve stimulator interscalene block, the patient's diaphragm begins to twitch. In order to successfully perform the block, the needle should be redirected in the following manner A. Advanced because the needle tip is too shallow B. Redirected anteriorly because the needle tip is too posterior C. Redirected posteriorly because the needle tip is too anterior D. Withdrawn because the needle tip is too deep.
Answer: C. Redirected posteriorly because the needle tip is too anterior
Characteristics of omphalocele include (select 2): A. Location lateral to the umbilicus B. Lacks a hernia sac C. Results from the failure of midgut migration into the abdomen D. Nitrous oxide should be used during the repair to ensure a rapid emergence E. Association with Beckwith-Wiedemann Syndrome (Trisomy 21) F. Results from abnormal development of the right omphalomesenteric artery.
Answer: C. Results from the failure of midgut migration into the abdomen E. Association with Beckwith-Wiedemann Syndrome (Trisomy 21) Gastroschisis and omphalocele are characterized by defects in the abdominal wall that allow herniation of the viscera. Omphaloceles occur at the base of the umbilicus, have a hernia sac and are commonly associated with other anomalies. In contrast, gastroschisis is usually lateral to the umbilicus, lacks a hernia sac and is usually an isolated finding. Nitrous oxide is best avoided during repair as it may result in bowel distention making closure more difficult. Page 901 Morgan & Mikhail's Clinical Anesthesiology.
Lamina flow in the airway occurs in the: select 2 A. Trachea B. Main stem bronchi C. Terminal bronchiole D. 3rg Generation bronchus E. Respiratory bronchiole
Answer: C. Terminal bronchiole E. Respiratory bronchiole Flow in the larger airways is mostly turbulent. Laminar flow normally occurs only distal to small bronchioles (<1mm). The Reynolds number is used to predict the type of airway flow; a low Reynolds number (< 1000) is associated with laminar flow, whereas a high value (> 1500) is associated with turbulent flow. Pages 498-499 Morgan & Mikhail's Clinical Anesthesiology
22. A 46-year-old male is scheduled for an emergent laparotomy for small bowel obstruction. His history is complicated by the acute onset of hepatitis B four days earlier and he presents with significant scleral jaundice. The perioperative mortality in this patient is approximately: A) 2% B) 25% C) 5% D) 10%
Answer: D) 10% Patients with acute hepatitis should have elective surgery postponed until the acute hepatitis has resolved. Studies indicate increased perioperative morbidity (12%) and mortality (10% with laparotomy) during acute hepatitis.
10. The number of dichotomous divisions of the tracheobronchial tree from the trachea to the alveolar sacs is approximately: A) 9 B) 31 C) 15 D) 23
Answer: D) 23 Dichotomous division, each branch dividing into two smaller branches, of the tracheobronchial tree is estimated to involve 20 - 25 divisions.
45. The National Institute for Occupational Safety (NIOSH) recommends limiting the operating room concentration of nitrous oxide to: A) 0.5 ppm B) 50 ppm C) 5 ppm D) 25 ppm
Answer: D) 25 ppm NIOSH recommends limiting the room concentration of nitrous oxide to 25 ppm and halogenated agents to 2 ppm (0.5 ppm if nitrous oxide is also being used).
42. A 24-year-old female is scheduled for resection of a cerebral aneurysm. She has no other significant past medical history. Acceptable levels of hypotension would include a mean arterial pressure of: A) 20 - 30 mmHg B) 90 - 100 mmHg C) 35 - 45 mmHg D) 50 - 60 mmHg
Answer: D) 50 - 60 mmHg Healthy young individuals tolerate mean arterial pressures as low as 50 - 60 mmHg without complications. Chronically hypertensive patients have altered autoregulation of cerebral blood flow and may tolerate a mean arterial pressure of no more than 20 - 30% below baseline.
20. The incidence of chronic active hepatitis following infection with the hepatitis C virus is approximately: A) 10% B) 75% C) 25% D) 50%
Answer: D) 50% The incidence of chronic active hepatitis following hepatitis C infection is at least 50%; 3 - 10% following hepatitis B infection
4. The body mass index (BMI) associated with extreme obesity is: A) > 30 B) > 45 C) > 35 D) > 40
Answer: D) > 40 Overweight and obesity are classified using the BMI. Overweight is defined as a BMI > 24, obesity as a BMI > 30 and extreme obesity as a BMI > 40. BMI is calculated with the following formula: BMI = Weight (kg) / Height (meters)2
38. An increase in the plasma concentration and a prolongation of the elimination half-life of etomidate is seen with the concomitant administration of: A) Midazolam B) Succinylcholine C) Rocuronium D) Fentanyl
Answer: D) Fentanyl Fentanyl has been shown to increase the plasma level of etomidate as well as prolong the elimination half-life of the drug
46. The highest incidence of muscle pain following the use of succinylcholine is seen in: A) Infants B) Pregnant patients C) Octogenarians D) Outpatients
Answer: D) Outpatients Myalgia following the use of succinylcholine is most commonly seen in females and outpatients. Pregnancy and extremes of age seem to be protective.
15. Positive end expiratory pressure (PEEP): A) decreases dead space B) decreases extravascular lung water C) increases venous return to the heart D) decreases intrapulmonary shunting
Answer: D) decreases intrapulmonary shunting The major effect of PEEP is to increase FRC and tidal ventilation above the closing capacity. This results in a decrease in intrapulmonary shunting. Neither PEEP or CPAP decrease extravascular lung water. By increasing intrathoracic pressure, PEEP decreases venous return to the heart.
13. Stimulation of the parasympathetic nervous system results in: A) far vision accommodation B) contraction of the urinary sphincter C) increased inotropy D) increased insulin secretion
Answer: D) increased insulin secretion Insulin secretion is increased by stimulation of the parasympathetic nervous system through the vagus nerves
18. In the absence of hypoxia or severe anemia, the best determinant of the adequacy of cardiac output is: A) cardiac output B) arterial oxygen content C) cardiac index D) mixed venous oxygen tension
Answer: D) mixed venous oxygen tension Both cardiac output and cardiac index have a wide range and may not reflect the adequacy of cardiac output against metabolic requirements. During periods of increased oxygen consumption, mixed venous oxygen tension is the best indicator of the adequacy of cardiac output.
9. The most common complication of thoracic paravertebral nerve block is: A) hypotension B) intravascular injection Top of Form C) subarachnoid injection D) pneumothorax
Answer: D) pneumothorax Pneumothorax is the most common complication of paravertebral block and a chest radiograph is needed upon completion of the block. Other complications include subarachnoid injection, epidural injection, intravascular injection, and hypotension.
16. The essential component of cardioplegia solutions is: A) mannitol B) corticosteroid C) magnesium D) potassium
Answer: D) potassium High concentrations of potassium (10 - 40 mEq/L) are used in cardioplegia solutions. These solutions result in an increase in extracellular potassium and reduce transmembrane potential. This progressively interferes with the normal sodium currents of depolarization and eventually the sodium channels are completely inactivated.
41. Sensory innervation of the trachea and larynx below the vocal cords is supplied by the: A) internal laryngeal nerve B) glossopharyngeal nerve C) external laryngeal nerve D) recurrent laryngeal nerve
Answer: D) recurrent laryngeal nerve The vagus nerve provides sensation to the airway below the epiglottis. The superior laryngeal branch of the vagus divides into an external (motor) and internal (sensory) laryngeal nerve that provide sensory supply to the larynx between the epiglottis and the vocal cords. Another branch of the vagus, the recurrent laryngeal nerve, innervates the larynx below the vocal cords and trachea.
The loss of ventricular filling as a result of acute atrial fibrillation is approximately: A- 30-45% B- 22-45% C- 100% D- 15-25%
Answer: D- 15-25% Passive flow accounts for about 75-80% of ventricular filling. The remaining 15-25% occurs as a result of atrial contraction, which is lost during atrial fibrillation. Page 249. Barash, Clinical Anesthesia
During emergent transtracheal jet ventilation using a 14 gauge catheter, generation of sufficient gas flow requires a driving pressure of: A. 20cmH2O B. 50cmH2O C. 25psi D. 50psi
Answer: D. 50psi After proper location of the catheter is confirmed by aspiration air, jet ventilation may be achieved with intermittent pulses of oxygen at 50 psi Page 1237 Morgan & Mikhail's Clinical Anesthesiology
Bone marrow depression and peripheral neuropathy have been associated with prolonged exposure to anesthetic concentrations of: A. Isoflurane B. Desflurane C. Sevoflurane D. Nitrous Oxide
Answer: D. Nitrous Oxide By irreversibly oxidizing the cobalt atom in vitamin B12, nitrous oxide inhibits vitamin B12 dependent enzymes. These enzymes include methionine synthetase and thymidylate synthetase. As a result of these enzyme inhibitions, prolonged exposure to nitrous oxide has been associated with bone marrow depression, megaloblastic anemia, peripheral neuropathy and teratogenicity. Page 471. Clinical Anesthesia Barash.
A 75 years old woman complains of loss of vision in one eye. She reports that she foirst noticed blurred vision in the right eye. This progressed to her bumping into objects on the right side. When she is asked to read, she can only read one half of sentences on a page. She has normal strength, coordination, reflexes and tone. Her cranial nerve exam shows that she cannot see a moving finger on the right filed in either eye. An occlusion of which major vessel is associated with these findings? A. Basilar artery B. Internal carotid artery C. Middle cerebral artery D. Posterior cerebral artery
Answer: D. Posterior cerebral artery The description of this patient suggests that she has a right visual filed deficit, in both eyes, as opposed to monocular blindness (the classic "anaurosis fugax" typically due to emboli from an internal carotid artery source). Although patients may describe not being able to see out of one eye, a cursory physical exa will reveal that the eye can see, but there may be significant field cut in both eyes. The neurological team for this sign is homonymous hemianopsia, and it is most commonly due to occipital lobe injury from a posterior cerebral artery infarction. Although field cuts can also occur with temporal or parietal lesions, there tends to be other associated findings not seen in this patient (such as neglect). References: stroke and related disorders
A 55 year old 70 kg man with history of asthma and seasonal allergies has a sudden rise in peak inspiratory pressure intraoperatively. The patient is otherwise hemodynamically stable and you suspect bronchospasm. The following management options exist to treat bronchospasm EXCEPT: A. Epinephrine B. Isoflurane C. Ketamine D. Propranolol
Answer: D. Propranolol Propranolol is a non-selective beta blocker that would be contraindicated in bronchospasm as it may elicit bronchoconstriction via beta-2-blockade. Ketamine, inhalational agents, epinephrine, and even propofol all have bronchodilatory effects and may be used to treat intraoperative bronchospasm. Perioperative considerations for the patient with asthma and bronchospasm. J Anaesth 2009, 103
Sickle hemoglobin: (select 2) A. Has a lower P50 than hemoglobin A B. Releases oxygen less readily than hemoglobin A C. Is present in about 30% of African Americans D. Readily polymerizes and precipitates in the red cell E. Results from a single amino acid substitution on the Alpha chain F. Has decreased solubility as compared to hemoglobin A
Answer: D. Readily polymerizes and precipitates in the red cell F. Has decreased solubility as compared to hemoglobin A Sickle hemoglobin (HbS) has a lower affinity for oxygen and an elevated P50 (31mm Hg) as compared to hemoglobin A (27 mmHg). HbS also has decreased solubility and readily polymerises and precipitates in the red cell producing the sickled appearance of the cell. HbS results from the substitution of valine for glutamic acid on the Beta-chain, Pg 1177 Morgan & Mikhail's Clinical Anesthesiology.
A 46-year old male is scheduled for an emergent laparotomy for small bowel obstruction. His history is complicated by the acute onset of hepatitis B four days earlier and he presents with significant scleral jaundice. The perioperative mortality in this patient is approximately: A. 2% B. 5% C. 10% D. 25%
Answer: C. 10% Patient with acute hepatitis should have elective surgery postponed until the acute hepatitis has resolved. Studies indicate increased perioperative morbidity (12%) and mortality (10% with laparotomy) during acute hepatitis. Pp. 1315-1316 Barash, Clinical Anesthesia.
During surgical repair of a detached retina, 1mL of sulfur hexafluoride is injected into the posterior chamber. If the patient is receiving 4% desflurane and a 2.1 ration of N2O and O2, the pressure-volume relationship of the bubble will approximately: A. Decrease in to about 0.67 B. Remain the same C. Double D. Triple
Answer: D. Triple A sulfur hexafluoride gas bubble is sometimes used to support the retina after detachment. Diffusion of nitrous oxide into the bubble will cause expansion as nitrous oxide equilibrates with the gas bubble. A sixty-seven percent nitrous oxide concentration will cause the bubble to triple in its pressure-volume relationship in about 30 minutes and may double the intraocular pressure (IOP). IN addition, when nitrous oxide is discontinued, the bubble will return to normal size, causing a fall in IOP and possible extension of the retinal tear. For these reasons, it is recommended that nitrous oxide be discontinued at least 15 minutes prior to the injection of a posterior chamber bubble. Page 762Morgan & Mikhail's Clinical Anesthesiology
What is auto regulation?
Answer: Most tissue beds regulate their own blood flow (autoregulation). Arterioles generally dilate in response to reduced perfusion pressure or increased tissue demand. Conversely, arterioles constrict in response to increased pressure or reduced tissue demand. These phenomena are likely due to both an intrinsic response of vascular smooth muscle to stretch and the accumulation of vasodilatory metabolic by-products. The latter may include K+, H+, CO2, adenosine, and lactate.
The rhythm strip below is indicative of:
Answer: Sinus Bradycardia A heart rate less than 60 beats per minute (BPM). This in a healthy athletic person may be 'normal', but other causes may be due to increased vagal tone from drug abuse, hypoglycemia and brain injury with increase intracranial pressure (ICP) as examples Looking at the ECG you'll see that: • Rhythm - Regular • Rate - less than 60 beats per minute • QRS Duration - Normal • P Wave - Visible before each QRS complex • P-R Interval - Normal • Usually benign and often caused by patients on beta blockers
The rhythm strip below is indicative of:
Answer: Sinus Tachycardia An excessive heart rate above 100 beats per minute (BPM) which originates from the SA node. Causes include stress, fright, illness and exercise. Not usually a surprise if it is triggered in response to regulatory changes e.g. shock. But if their is no apparent trigger then medications may be required to suppress the rhythm Looking at the ECG you'll see that: • Rhythm - Regular • Rate - More than 100 beats per minute • QRS Duration - Normal • P Wave - Visible before each QRS complex • P-R Interval - Normal • The impulse generating the heart beats are normal, but they are occurring at a faster pace than normal. Seen during exercise
The rhythm strip below is indicative of :
Answer: Supraventricular Tachycardia (SVT) Abnormal A narrow complex tachycardia or atrial tachycardia which originates in the 'atria' but is not under direct control from the SA node. SVT can occur in all age groups Looking at the ECG you'll see that: • Rhythm - Regular • Rate - 140-220 beats per minute • QRS Duration - Usually normal • P Wave - Often buried in preceding T wave • P-R Interval - Depends on site of supraventricular pacemaker • Impulses stimulating the heart are not being generated by the sinus node, but instead are coming from a collection of tissue around and involving the atrioventricular (AV) node
Name the different types of hypersensitivity reactions
Answer: There are 4 types of hypersensitivity reactions: Type 1 reactions are immediate-type reactions, including anaphylaxis. Signs & symptoms are the result of the release of histamine and other autocoids from mast cells & basophils. Type 2 reactions are cytotoxic reactions and cell mediated. ABO-incompatibility reactions are of this type. Type 3 reactions are the result of soluble antigens and antibodies combining to form insoluble complexes. Neutrophils are activated and tissue damage results. Serum sickness and Arthus reactions are examples of Type 3 reactions. Type 4 reactions are also known as delayed hypersensitivity reactions. These are the result of antigens reacting with sensitized lymphocytes. Contact dermatitis is an example of a Type 4 reaction.
14. The formation clinically significant amounts of carbon monoxide has been associated with: a) the use of a non-rebreathing circuit b) the use of fresh carbon dioxide absorber c) the use of desflurane d) expiratory valve incompetence
Answer: c) the use of desflurane The formation of CO depends on the use of a volatile agent containing a difluoromethoxy moiety (desflurane, isoflurane, enflurane). This moiety can react with desiccated base (baralime or sodalime) to form CO. Fresh absorber has sufficient water to prevent the reaction. Clinically, CO intoxication occurs after a weekend when the flow of dry oxygen in the machine has desiccated the absorber and desflurane is being used.
49. Local anesthetics with the potential to form methemoglobin include: (Select 3) a) EMLA topical anesthetic cream b) Bupivacaine c) Benzocaine d) Ropivacaine e) Prilocaine f) Mepivacaine
Answer: o a) EMLA topical anesthetic cream o e) Prilocaine o c) Benzocaine EMLA cream contains both lidocaine and prilocaine. The metabolites of prilocaine can convert hemoglobin to methemoglobin. Benzocaine can also cause methemoglobinemia. Case studies have also associated methemoglobinemia with tetracaine and lidocaine use.
17. Forms of mechanical ventilation that produce tidal volumes at or below anatomic dead space include: (Select 2) a) high-frequency oscillation b) inverse I:E ratio ventilation c) airway pressure release ventilation d) differential lung ventilation e) high-frequency positive-pressure ventilation f) pressure support ventilation
Answer: o a) high-frequency oscillation o e) high-frequency positive-pressure ventilation High-frequency oscillation (HFO) creates a to-and-fro gas movement in the airway at rates of 180 - 3000 times/min. High frequency positive-pressure ventilation is delivered at a rate of 60 - 120 breaths/min. Tidal volume is at or below anatomic dead space. High-frequency ventilation techniques may be useful in cases of bronchopleural and tracheoesophageal fistulas.
50. During hip replacement surgery, cardiopulmonary changes associated with the application of acrylic bone cement include: (Select 3) a) hypotension secondary to cement monomer absorption b) hypoxemia secondary to air embolization c) hypoxemia secondary to fat embolization d) hypocarbia e) decreased pulmonary artery pressure f) increased end-tidal carbon dioxide
Answer: o a) hypotension secondary to cement monomer absorption o b) hypoxemia secondary to air embolization o c) hypoxemia secondary to fat embolization During hip replacement surgery, hypotension associated with the use of acrylic bone cement has been attributed to absorption of methyl methacrylate monomer, embolization of air and bone marrow, lysis of red cells and marrow and conversion of methyl methacrylate to methacrylic acid. Hypoxemia is common. Embolic events cause an increase in dead space with a reduction in ETCO2 with an increase in PaCO2. (Nagelhout pg. 977, Barash pg. 1389)
47. The cardiovascular effects of pancuronium are caused by: (Select 3) a) vagal blockade b) stimulation of cardiac muscarinic receptors c) ganglionic stimulation d) decreased catacholamine reuptake e) direct myocardial stimulation f) blockade of cardiac slow calcium channels g) central thalamic stimulation
Answer: o a) vagal blockade o c) ganglionic stimulation o d) decreased catecholamine reuptake The cardiovascular effects of pancuronium are caused by the combination of vagal blockade and sympathetic stimulation. The latter is due to a combination of ganglionic stimulation, catecholamine release and decreased catecholamine reuptake.
6. Renal blood flow: (Select 2) a) is largely determined by renal oxygen consumption b) accounts for 20 - 25% of the cardiac output c) is distributed mostly to juxtamedullary nephrons d) can be directed away from cortical nephrons by sympathetic stimulation e) is not autoregulated
Answer: o b) accounts for 20 - 25% of the cardiac output o d) can be directed away from cortical nephrons by sympathetic stimulation The kidneys are the only organ for which oxygen consumption is determined by blood flow; the reverse is true in other organs. The kidneys receive 20 - 25% of the cardiac output with only 10 - 15% going to the juxtamedullary nephrons and 80% going to cortical nephrons. However, blood flow can be redirected to juxtamedullary nephrons by increased levels of catecholamines and angiotensin II. Autoregulation of RBF occurs between mean arterial pressures of 80 - 180 mmHg.
5. Release of aldosterone by the adrenal cortex is stimulated by: (select 3) a) angiotensin I b) angiotensin II c) hypokalemia d) pituitary ACTH e) congestive heart failure f) hypervolemia
Answer: o b) angiotensin II o d) pituitary ACTH o e) congestive heart failure Aldosterone release is stimulated by the renin-angiotensin system, but specifically by angiotensin II. Other causes of aldosterone release include hyperkalemia, ACTH release, hypovolemia, hypotension, CHF and the stress response
23. An increase in intraocular pressure has been associated with: (select 3) a) nitrous oxide administration b) succinylcholine administration c) opioid administration d) hyperventilation e) laryngoscopy f) hypoxemia g) sevoflurane administration
Answer: o b) succinylcholine administration o f) hypoxemia o e) laryngoscopy Succinylcholine increases intraocular pressure by 5 - 10 mmHg for 5 - 10 minutes after administration. This increase is primarily the result of prolonged contracture of the extraocular muscles from the depolarizing effects of succinylcholine. Nitrous oxide, volatile anesthetic agents and opioids have been associated with a reduction in intraocular pressure. Hypoxemia, hypercarbia, hypertension, hypervolemia, laryngoscopy and intubation have all been shown to increase IOP.
27. Factors increasing the affinity of hemoglobin for oxygen include: (Select 2) a) increased carbon dioxide levels b) increased 2,3-DPG levels c) increased pH d) the presence of fetal hemoglobin e) increased body temperature f) the presence of hemoglobin-S
Answer: o c) increased pH o d) presence of fetal hemoglobin Factors that increase the affinity of hemoglobin for oxygen would cause a leftward shift of the hemoglobin dissociation curve and a decrease in the P50. These factors include alkalosis, decreased CO2 levels, and decreased 2,3-DPG levels. Hemoglobin-S, found in patients with sickle cell disease, has a decreased affinity for oxygen. Fetal hemoglobin, however, has an increased affinity for oxygen to help in oxygen transfer from the mother to the fetus
28. Laminar flow in the airway occurs in the: (Select 2) a) trachea b) main stem bronchi c) terminal bronchiole d) 3rd generation bronchus e) respiratory bronchiole
Answer: o c) terminal bronchiole o e) respiratory bronchiole Flow in the larger airways is mostly turbulent. Laminar flow normally occurs only distal to small bronchioles (< 1mm). The Reynolds number is used to predict the type of airway flow; a low Reynolds number (< 1000) is associated with laminar flow, whereas a high value (> 1500) is associated with turbulent flow
29. Sickle hemoglobin: (Select 2) a) has a lower P50 than hemoglobin A b) releases oxygen less readily than hemoglobin A c) is present in about 30% of African Americans d) readily polymerizes and precipitates in the red cell e) results from a single amino acid substitution on the α-chain f) has decreased solubility as compared to hemoglobin A
Answer: o d) readily polymerizes and precipitates in the red cell o f) has decreased solubility as compared to hemoglobin A Sickle hemoglobin (HbS) has a lower affinity for oxygen and an elevated P50 (31 mmHg) as compared to hemoglobin A (27 mmHg). HbS also has decreased solubility and readily polymerizes and precipitates in the red cell producing the sickled appearance of the cell. HbS results from the substitution of valine for glutamic acid on the β-chain.
7. A 36-year-old female is scheduled for an elective cholecystectomy. Her past medical history is significant for depression treated with phenelzine (Nardil). Her anesthetic plan should include: (Select 2) a) discontinuation of phenelzine for at least 2 weeks prior to surgery b) the avoidance of indirect acting vasopressors c) the avoidance of propofol d) the avoidance of meperidine e) the avoidance of nitrous oxide the avoidance of volatile anesthetic agents
Answer: o d) the avoidance of meperidine o b) the avoidance of indirect acting vasopressors Phenelzine is a monamine oxidase (MAO) inhibitor. The practice of discontinuing MAO inhibitors prior to surgery is no longer recommended. The use of meperidine in patients receiving MAO inhibitors has been associated with hypertensive crisis and should be avoided. Additionally, indirect acting vasopressors have also been associated with hypertensive crisis and direct acting vasopressors should be used to treat hypotension.
Pulmonary changes associated with Duchenne's muscular dystrophy include: A. A restrictive ventilator defect B. An obstructive ventilator defect C. Decreased pulmonary artery pressure D. Increased residual volume
Answer: A restrictive ventilator defect Pulmonary changes associated with Duchenne's muscular dystrophy include: a restrictive ventilator defect. The combination of marked kyphoscoliosis and degeneration of the respiratory muscles produces a severe restrictive ventilator defect in patients with Duchenne's muscular dystrophy. Pulmonary hypertension is also commonly seen. (Page 753 Morgan & Mikhail's Clinical Anesthesiology, 2013). Muscular Dystrophy Core Notes by Core Concepts Anesthesia Review, LLC 1. Duchenne muscular dystrophy (DMD) is the most common type of muscular dystrophy. 2. It is an X-linked disorder seen in males, appearing in childhood with progressive muscle wasting. Death usually occurs during adolescence. 3. Cardiac muscle is also affected and death usually results from cardiac and/or ventilator failure. 4. ECG changes appear as decreased R-wave amplitude and the appearance of Q waves. 5. Changes in the architecture of the thorax result in progressive and severe restrictive lung disease. 6. Severe hyperkalemia and rhabdomyolysis have resulted from the administration of succinylcholine. The use of succinylcholine is contraindicated in these patients. 7. Although once felt to be associated with MH, recent data suggest that this may not be true and deaths were likely the result of hyperkalemia. DMD is the most common childhood muscular dystrophy. It is an X-linked recessive disorder appearing in between the ages of 3 - 5, with progressive weakness. It is sometimes referred to as pseudohypertrophic muscular dystrophy and is usually fatal by late adolescence as a result of ventilatory and/or cardiac failure. In addition, these young males suffer from contractures, marked scoliosis, restrictive lung disease, and cardiomyopathies; 50% of sufferers have a dilated cardiomyopathy by the age of 15. The disease is a result of a lack of dystrophin, a protein that helps to hold muscle cells to the extra-cellular matrix. This leads to a weakening of the sarcolemma, which becomes increasingly permeable, with increased intracellular calcium levels. Other less-common forms of muscular dystrophy also occur including: Emery-Dreifuss muscular dystrophy, limb-girdle muscular dystrophy, Becker's muscular dystrophy, oculopharyngeal muscular dystrophy, fascioscapulohumeral muscular dystrophy and congenital muscular dystrophy. The most significant anesthetic complications in patients with DMD are the result of the actions of volatile anesthetics or neuromuscular blocking agents on the cardiac and skeletal muscle. Cases of cardiac arrest have been reported and are associated with severe hyperkalemia and rhabdomyolysis. In patients with muscular dystrophy, succinylcholine appears to damage the weakened sarcolemma causing release of intracellular contents and is absolutely contraindicated. Patients frequently have prolonged recovery from nondepolarizing relaxants. Anticholinesterase agents have also been implicated in muscle breakdown. Additional Reading: Barash, PG, Cullen, BF, Stoelting, RK, Cahalan, MK, Stock, MC, and Ortega, R. Clinical Anesthesia. Philadelphia: Lippincott Williams & Wilkins, 2013:613
In the thromboelastograms above, thrombocytopenia is best represented by: A B C D
Answer: C Thrombocytopenia cases an overall reduction in clot strength shown as a narrowing in the thromboelastogram. Page 1519 Barash, Clinical Anesthesia
Dextran 40 has been shown to improve microcirculation by: A- Reducing blood density B- Increasing blood density C- Decreasing blood viscosity D- Increasing blood viscosity
Answer: C- Decreasing blood viscosity Dextran 40 has been shown to improve microcirculation presumably by decreasing blood viscosity thereby improving laminar flow in the microcirculatory beds. Both dextran 4o and Dextran 70 possese antiplatelet effects and may interfere with blood typing. Page 1165 Morgan & Mikhail's Clinical Anesthesiology
The highest level of protein binding is seen with: A- Procaine B- Lidocaine C- Mepivacaine D- Bupivacaine
Answer: D Bupivacaine The physicochemical property that determines the duration of action of local anesthetic is lipid solubility, which is directly correlated with plasma protein binding. Bupivacaine and Levobupivacaine have the highest degree of protein binding (97%). Page 269 Morgan & Mikhail's Clinical Anesthesiology
Maternal mortality associated with amniotic fluid embolization is: A- 10-15% B- 20-25% C- 40-45% D- Greater than 50%
Answer: D- Greater than 50% Amniotic fluid embolism is a very rare occurrence of about 1:20,000. However, it carries a very high mortality; some studies quoting as much as 86%. Mortality within the first hour after onset is about 50%. Page 867 Morgan & Mikhail's Clinical Anesthesiology
In patients receiving Vecuronium, the greatest augmentation of neuromuscular blockade is seen the use of? A. Isoflurane B. Sevoflurane C. Desfurane D. Nitrous Oxide
C. Desflurane Volatile agents decrease the non depolarizer dosage requirement. The degree of augmentation of blockade depend on the inhalation agent Desflurane >Sevoflurane> Isoflurane>Nitrous Oxide Page 213 Morgan & Mikhail's Clinical Anesthesiology
The addition of bicarbonate to a local anesthetic solution: A. Delays the onset of blockade B. Increases the concentration of the nonionic form of the local anesthetic C. Causes a fall in eth pH of the solution D. Should only be done when using bupivacaine
B. Increases the concentration of the nonionic form of the local anesthetic The onset of neural blockade depends on eth penetration of the nerve cell membrane by the nonionic form of the anesthetic. Increasing the pH of the anesthetic solution increases the concentration of the nonionic form and thereby hastens the onset of the block. Bicarbonate is usually not added to bupivacaine, since it can cause precipitation if the pH is raised above 6.8 Page 963 Morgan & Mikhail's Clinical Anesthesiology