Core Concepts Anesthesia Board Questions
The risk of paradoxical air embolism is increased in patients with a patent foramen ovale. The incidence of patent foramen ovale in the adult population is approximately:
10-25% The incidence of venous air embolism is highest during sitting crainotomies, with an incidence of 20 - 40%. The risk of paradoxical venous air embolization is increased in patients with patent foramen ovale, which has a reported incidence of 10 - 25% in the adult population.
The loss of ventricular filling as a result of acute atrial fibrillation is approximately:
15-25% Passive flow accounts for about 75 - 85% of ventricular filling. The remaining 15 - 25% occurs as a result of atrial contraction, which is lost during atrial fibrillation.
The number of dichotomous divisions of the tracheobronchial tree from the trachea to the alveolar sacs is approximately:
20-25 Dichotomous division, each branch dividing into two smaller branches, of the tracheobronchial tree is estimated to involve 20 - 25 divisions.
The elimination half-time of a drug: a. is inversely proportional to the clearance b. is inversely proportional to the volume of distribution c. is directly proportional to clearance d. is shortest in drugs that are rapidly redistributed
A The elimination half-timeof a drug is proportional to the volume of distribution and inversely proportional to the rate of clearance.
A nonselective α-antagonist used in the preoperative preparation of a patient with pheochromocytoma is: a. phenoxybenzamine b. doxazosin c. propranolol d. terazosin
A Phenoxybenzamine is a nonselective α-antagonist used in the preoperative preparation of the patient with pheochromocytoma. Doxazosin and terazosin are selective α1-antagonists. Propranolol is a nonselective β-antagonist. In the preparation of patients with pheochromocytoma, α-blockade and intravascular volume replacement must precede β-blockade, so as to prevent the possibility of unopposed α-stimulation.
The single greatest cause of mortality in the patient with sickle cell disease is a result of: a. acute chest syndrome b. sequestration crisis c. aplastic crisis d. vaso-occlusive crisis
A ACS represents the single greatest threat to the patient with SCD as the mortality is 1% to 20%. The diagnosis of ACS can be made when there are new lung infiltrates on a chest radiograph in the presence of any of the following: chest pain, cough, dyspnea, wheezing, or hypoxemia. Proposed mechanisms of ACS are thrombosis, embolism (clot and fat), and infection. The frequency of ACS after abdominal surgery is 10% to 20%.
Correct statements concerning the use of benzodiazepines in the elderly include: a. volume of distribution is increased b. reduced pharmacodynamic sensitivity is observed c. the elimination half-life of diazepam, but not midazolam, is increased d. all of the above
A Aging increases the volume of distribution for all benzodiazepines, effectively prolonging their elimination half-times. Enhanced pharmacodynamic sensitivity is also observed. The elimination half-times of both diazepam and midazolam are increased.
A person acting as an amicus curiae: a. is not a party to the litigation b. gives expert testimony c. for the defense gives expert testimony d. for the plaintiff cannot file a written brief
A Amicus curiae is a phrase that literally means 'friend of the court' -- someone who is not a party to the litigation, but who believes that the court's decision may affect its interest. An expert, not associated with either the defendant or plaintiff may, at the court's discretion, file a brief or give testimony to assist the court in decision making.
An occurrence malpractice insurance policy: a. offers coverage if the policy was in place at the time of the incident, regardless of when the claim is filed b. offers coverage if the policy is in place at the time the claim is filed c. is activated at the time of the need to pay a claim that exceeds the limits of coverage on the standard malpractice policy d. is the most common form of malpractice insurance in place today
A An occurrence policy offers coverage of an incident resulting in a claim, whenever that claim might be filed. The much more common claims-made policy covers claims that are filed only while the insurance is in force. Umbrella coverage is activated at the time of the need to pay a claim that exceeds the limits of coverage on the standard malpractice policy.
The formation of metanephrine is the result of: a. catechol-O-methyltransferase metabolism of epinephrine b. catechol-O-methyltransferase metabolism of norepinephrine c. monamine oxidase metabolism of epinephrine d. monamine oxidase metabolism of norepinephrine
A Catechol-O-methyltransferase (COMT) metabolizes epinephrine to metanephrine and norepinephrine to normetanephrine. Subsequently, monamine oxidase (MAO) further metabolizes metanephrine and normetanephrine to vanillymandelic acid (VMA).
The diameter index system (DISS) is a national standard that ensures that the correct: a. gas hose enters the machine from the wall connection b. gas tank fits onto the hanger yoke c. oxygen tank is attached to the auxiliary oxygen source d. vaporizer is filled with the same halogenated agent
A DISS ensures that the correct pipeline gas enters the correct part of the anesthesia machine. Blue is nitrous oxide, green is oxygen, yellow is room air, white is the hospital vacuum, and purple is the waste gas scavenging vacuum.
Droperidol: a. has antiarrhytmic activity b. causes shortening of the QT interval c. causes peripheral vasoconstriction d. is effective for blood pressure control in patients with pheochromocytoma
A Droperidol has mild alpha-blocking activity and causes vasodilation and has antiarrhythmic properties with prolongation of the QT interval. As a result of the prolongation of the QT interval, droperidol has been associated with torsades de pointes and should not be given to patients with QT intervals measuring more than 440 ms. Patients with pheochromocytoma should not receive droperidol because it can induce catecholamine release.
In the neuromuscular junction, acetylcholine receptor binding sites are found on the: a. α-subunits b. β-subunits c. δ-subunits d. ε -subunits
A Each acetylcholine (ACh) receptor in the neuromuscular junction consists of 5 protein subunits. Only the α-subunits are capable of binding ACh molecules. If both binding sites are occupied, the channel briefly opens. The α-subunits are also the site of action of neuromuscular blockers.
Electrolyte containing irrigation solutions are avoided during transurethral resection of the prostate because they: a. interfere with the use of the cautery b. can precipitate severe hyponatremia c. can cause hyperglycemia in diabetic patients d. are associated with elevated ammonia levels postoperatively
A Electrolyte containing solutions conduct electricity and interfere with cautery use during the resection of the prostate. Electrolyte solutions are commonly used in the postop period. Sorbitol solutions have been associated with hyperglycemia, especially in diabetic patients. Glycine solutions have been associated with elevated ammonia levels and transient postoperative visual syndrome. Sorbitol, glycine and distilled water have all been associated with TURP syndrome.
The potency of local anesthetics increases as the: a. lipid solubility increases b. pKa increases c. number of double bonds in the anesthetic molecule increases d. molecular weight decreases
A Local anesthetic potency correlates directly with lipid solubility. In general, lipid solubility increases with an increase in the total number of carbon atoms in the molecule and by adding a halogen to the aromatic ring.
A nonselective α-antagonist used in the preoperative preparation of a patient with pheochromocytoma is: a. phenoxybenzamine b. doxazosin c. propranolol d. terazosin
A Phenoxybenzamine is a nonselective α-antagonist used in the preoperative preparation of the patient with pheochromocytoma. Doxazosin and terazosin are selective α1-antagonists. Propranolol is a nonselective β-antagonist. In the preparation of patients with pheochromocytoma, α-blockade and intravascular volume replacement must precede β-blockade, so as to prevent the possibility of unopposed α-stimulation.
Mortality after liposuction procedures most commonly is the result of: a. pulmonary embolism b. bowel perforation c. fat embolization d. reactions to anesthetic agents
A The mortality rate from liposuction procedures is approximately 0.02%. The most common cause of mortality is pulmonary embolism accounting for 23.1% of the deaths.
The age group with the highest minimum alveolar concentration (MAC) of desflurane is: a. 2 - 3 months b. 1 - 2 years c. 25 - 30 years d. greater than 75 years
A The two-to-three-months-of-age group represents the highest MAC requirement. MAC subsequently decreases with advancing age.
Which drugs are dosed based on total body weight in the patient with a BMI of 39 kg/m2? (Select 2) a. Cisatracurium (Nimbex) b. Lidocaine (Xylocaine) c. Propofol (Diprivan) D. Remifentanil (Ultiva)
A & B The increased fat content of obese patients affects the volume of distrubution of drugs. Cisatracurium and lidocaine are dosed based on total body weight. Propofol and remifentanil are dosed based on lean body weight.
Deleterious effects of hypothermia include: (Select 2) a. impaired renal function b. right shift of the hemoglobin-oxygen saturation curve c. irreversible platelet dysfunction d. increased incidence of wound infection e. increased postoperative protein anabolism
A & D • increased PVR • left shift of the hemoglobin-oxygen saturation curve • reversible platelet dysfunction • postoperative protein catabolism • altered mental status • impaired renal function • decreased drug metabolism • poor wound healing • increased incidence of infection • cardiac arrhythmias
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
A & D Absolute contraindications to epidural anesthesia/analgesia in the parturient include infection over the injection site, coagulopathy, thrombocytopenia, marked hypovolemia, true local anesthetic 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.
Signs of cardiac tamponade include: (Select 2) a. distended neck veins b. increased QRS voltage seen on ECG c. decreased central venous pressure d. bradycardia e. systemic vasoconstriction f. an increase in systolic blood pressure during inspiration
A and E Cardiac tamponade is indicated by the presence of neck vein distention, hypotension, muffled heart sounds (Beck's triad) and a greater than 10 mm Hg decline in blood pressure during spontaneous inspiration (pulsus paradoxus). Tachycardia and systemic vasoconstriction are present to maintain blood pressure with the associated decreased stroke volume.
What is the afferent and efferent limb of the occularcardiac reflex?
Afferent: Ciliary Nerve (of Trigeminal) Efferent: Vagus nuerve
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
A, B, & D 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 from renal disease is very common. Xerostomia and decreased lacrimation are a result of exocrine gland involvement.
Congenital heart diseases associate with right-to-left shunting include: (Select 3) a. tricuspid atresia b. hypoplastic left heart syndrome c. aortopulmonary window d. patent ductus arteriosus e. tetralogy of Fallot f. subvalvular aortic stenosis g. ventricular septal defects h. atrial septal defects
A, B, & E Right-to-left shunting (cyanotic) heart disease is associated with: Tetrology of Fallot, pulmonary atresia, triscupid atresia, transposition of the great vessels, truncus arteriosus, single ventricle, double-outlet ventricle, total anomalous pulmonary venous return and hypoplastic left heart.With tricuspid atresia, blood can flow out of the right atrium only via a patent foramen ovale (PFO). A PDA or VSD is necessary for the blood to flow from the left ventricle to the pulmonary circulation.
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
A, C, D 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.
Enoxaparin: a. causes less platelet inhibition than heparin b. is easily reversed with protamine c. has a half-life that is 35% less than that of heparin effects d. are monitored using the INR
A. Low molecular weight heparins (LMWH), such as enoxaparin, have greater activity against factor Xa than thrombin. As a result, the INR is not a reliable monitoring tool. The LMWHs cause less platelet inhibition and are associated with a lesser incidence of heparin induced thrombocytopenia.
According to the Modified Glasgow Coma Scale, a moderate head injury is associated with a score of: a. 13 - 15 b. 9 - 12 c. 6 - 9 d. less than 6
B 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.
A 5-day-old male is scheduled for a pyloromyotomy. The patient has experienced two episodes of apnea since birth. Anesthetic management shown to reduce the incidence of postoperative apnea includes: a. the use of ketamine as the sole anesthetic agent b. the intravenous administration of caffeine c. use of desflurane as the sole anesthetic agent d. the avoidance of nitrous oxide
B Both caffeine and theophylline have been shown to reduce the incidence of postoperatitive apnea in infants at increased risk. Caffeine is favored because of its wider therapeutic margin. The recommended loading dose is 10 mg/kg caffeine base.
The elimination half-life of intravenously administered oxytocin in the parturient is approximately: a. 30 to 120 seconds b. 3 to 5 minutes c. 10 to 15 minutes d. 20 to 30 minutes
B Both endogenous and intravenously administered oxytocin have short elimination half-lives of about 3 to 5 minutes. As a result, oxytocin must be administered as a continuous infusion for the induction of labor.
Reactants that are regenerated during the absorption of carbon dioxide by soda lime include: a. carbonic acid b. sodium hydroxide c. calcium hydroxide d. calcium carbonate
B Both water and sodium hydroxide are initially required during the absorption of carbon dioxide by soda lime, but then are regenerated.
Safety features that prevent filling of the vaporizer with an incorrect agent include: a. the pin index safety system b. agent-specific keyed filling ports c. the diameter index safety system d. counter-threading of the bottle attachment
B Modern vaporizers offer agent-specific keyed filling ports to prevent filling with an incorrect agent. The pin-index safety system is found on e-cylinders to prevent incorrect tank placement.
The largest fraction of carbon dioxide in the blood is in the form of: a. carbamino compounds b. bicarbonate c. dissolved gas d. carboxyhemoglobin
B Nearly 90% of carbon dioxide in the blood is in the form of bicarbonate.
Renal effects of nitrous oxide include: a. decreased renal blood flow secondary to decreased cardiac output b. decreased renal blood flow secondary to increased renal vascular resistance c. increased renal blood flow secondary to sympathetic stimulation d. increased glomerular filtration with increased reabsorption
B Renal effects of nitrous oxide include: decreased renal blood flow secondary to increased renal vascular resistance Nitrous oxide appears to decrease renal blood flow by increasing renal vascular resistance. This results in decreased glomerular filtration and decreased urine output.
Prior to pneumonectomy, split lung function testing is indicated in the patient with: a. an FEV1 of 2.2 L b. a PaCO2 of 49 mm Hg on room air c. a PaO2 of 54 mm Hg on room air d. a maximum VO2 of 21 mL/kg/min
B Split lung function testing is indicated in patients requiring pneumonectomy, but not meeting the recommended laboratory criteria. Current recommendations for patients requiring pneumonectomy are: • PaCO2 < 45 mm Hg • FEV1 > 2 L • Predicted postop FEV1 > 800 mL • Maximum VO2 > 15 mL/kg/min • FEV1/FVC > 50% of predicted
The formation of active metabolites has NOT been associated with the use of: a. vecuronium b. rocuronium c. pancuronium d. succinylcholine
B The 3-OH metabolites of both vecuronium and pancuronium possess about 50% of the neuromuscular blocking activity of parent compound. Succinylcholine is metabolized to choline, succinic acid and succinylmonocholine. Succinylmonocholine also has some neuromuscular blocking activity. A small amount of rocuronium is metabolized to the 17-OH compound, which lacks activity. Most rocuronium is excreted by the kidneys and liver as intact drug.
The portion of the nephron responsible for concentration of urine via the countercurrent mechanism is the: a. glomerulus b. loop of Henle c. proximal convoluted tubule d. distal convoluted tubule
B The loop of Henle is responsible for formation of hypertonic fluid in the (renal) medullary interstitium via the countercurrent multiplier system.
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
B 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.
Venous irritation associated with the injection of diazepam and lorazepam is secondary to: a. the high degree of water solubility of these agents b. the presence of propylene glycol as a solvent c. the presence of metabisulfite as a preservative d. the low pH of these agents
B Venous irritation associated with the injection of diazepam and lorazepam is secondary to: the high degree of water solubility of these agents the presence of propylene glycol as a solvent the presence of metabisulfite as a preservative the low pH of these agents
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
B 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.
Selective adrenergic stimulation of the β2-receptor results in: a. increased heart rate b. increased insulin secretion c. detrusor muscle contraction d. pupillary constriction
B β2-receptor stimulation results in: increased insulin secretion, bronchodilation, increased salivary gland secretion, decreased upper GI motility, gluconeogenesis, pupillary dilation and detrusor muscle relaxation. Increased heart rate is a result of β1-receptor stimulation. Pupillary constriction (miosis) is the result of parasympathetic stimulation.
Dantrolene: (Select 2) a. depends on an extracellular mechanism to achieve muscle relaxation b. inhibits calcium ion release from the sarcoplasmic reticulum c. can also be used in the treatment of thyroid storm d. therapy should not be repeated after an MH episode has terminated e. has a half-life of approximately 12 hours
B & C Dantrolene binds with the Ryr1 receptor and inhibits calcium ion release from the sarcoplasmic reticulum. Dantrolene's effects are intracellular and may result in muscle weakness and ventilatory insufficiency. The half-life of dantrolene is approximately 6 hours. Dantrolene has also been used to treat neuroleptic malignant syndrome and thyroid storm.
Indications for arterial canulation include: select 2 a. anticipated requirement for hyperventilation b. need for repeated blood sampling c. planned pharmacological or mechanical cardiovascular manipulation d. scheduled intraop nerve monitoring
B & C Rationale: Invasive blood pressure monitoring indications can include repeated sampling; cardiovascular manipulation; mitral valve stenosis; continuous, real-time blood pressure monitoring; failure of indirect arterial blood pressure measurement; and supplementary diagnostic information from the arterial waveform. Nerve monitoring and hypoventilation do not require arterial cannulation.
Pulmonary effects of β2-adrenergic stimulation include: (Select 2) a. inhibition of hypoxic pulmonary vasoconstriction b. decreased bronchial secretions c. pulmonary vasoconstriction d. bronchodilation e. redirection of blood flow to lower V/Q alveolar units f. activation of type II pneumocytes
B & D The tracheobronchial tree receives sympathetic innervation form the T1 - T4 nerve roots. β2 stimulation causes bronchodilation and decreased secretions. The sympathetic nervous system has minimal effects on pulmonary vascular tone. However, α1 stimulation causes some degree of pulmonary vasoconstriction.
Respiratory parameters that are increased during pregnancy include: (Select 2) a. airway resistance b. tidal volume c. oxygen consumption d. plasma bicarbonate levels e. functional residual capacity f. PaCO2
B &C Respiratory/ventilatory effects of pregnancy include increased oxygen consumption, decreased airway resistance, decreased FRC, increased tidal volume and rate, increased PaO2, decreased PaCO2 and decreased serum bicarbonate.
Prior to induction, which drugs should be administered to a 24-week parturient who presents to the operating room for a laparoscopic cholecystectomy? (Select 2) a. Calcium Carbonate b. Famotidine (Pepcid) c. Omeprazole (Prilosec) d. Sodium citrate
B and D A parturient after 12 weeks' gestation has an increased risk of gastric regurgitation and pulmonary aspiration during induction of anesthesia. The risk of aspiration can be decreased by administering sodium citrate, a histamine (H2)-receptor antagonist, and a gastrokinetic drug.
Parasympathetic preganglionic fibers are found in: (Select 3) a. cranial nerve IV b. cranial nerve VII c. cranial nerve IX d. cranial nerve XI e. thoracic nerve 9 f. thoracic nerve 11 g. sacral nerve 1 h. sacral nerve 2
B, C, & H Parasympathetic preganglionic fibers are found in cranial nerves III, VII, IX and X as well as sacral nerves 2, 3 and 4.
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
B, D, E 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.
Sinus arrhythmia: a. is mediated through sympathetic innervation of the AV node b. causes an increase in heart rate with inspiration c. is indicative of SA node ischemia d. is the primary cause of premature atrial contractions
B. Sinus arrhythmia is a cyclic variation in heart rate that corresponds to ventilation, increasing with inspiration and decreasing with expiration. Sinus arrhythmia is a normal cardiac rhythm and is due to cyclic changes in vagal tone.
Clinical signs of tension pneumothorax include: a. contralateral absence of breath sounds b. ipsilateral hyporesonance to percussion c. neck vein distention d. all of the above
C A tension pneumothorax develops from air entering the pleural space through a one-way valve in the lung or chest wall. Clinical signs include ipsilateral absence of breath sounds, hyperresonance to percussion, contralateral tracheal shift and distended neck veins.
Physiologic effects of electroconvulsive therapy (ECT) include an: a. initial sympathetic response with sustained tachycardia b. initial sympathetic discharge followed by a sustained parasympathetic response c. initial parasympathetic discharge followed by a sustained sympathetic response d. initial parasympathetic response with sustained bradycardia
C An initial parasympathetic discharge followed by a sustained sympathetic response is immediately seen after the nduction of a seizure. Marked bradycardia with increased secretions can occur, which is then followed by hypertension and tachycardia. Patients scheduled for ECT are routinely given anticholinergic medication preoperatively.c
The effects of barbiturates on ischemic areas of the brain include: a. vasoconstriction b. vasodilation c. redirection of blood flow to the ischemic areas d. redirection of blood flow away from ischemic areas
C Barbiturates cause cerebral vasoconstriction in normal areas. These agents tend to redistribute blood flow to ischemic areas in what is sometimes referred to as a reverse steal phenomenon or Robin Hood effect. Ischemic areas remain maximally dilated and unaffected by the barbiturate.
Drugs that inhibit coagulation through direct inhibition of thrombin include: a. heparin b. warfarin c. bivalirudin d. aprotonin
C Bivalirudin, hirudin, lepirudin and argatroban are anticoagulants that directly inhibit thrombin. These agents are most commonly used for cardiopulmonary bypass when heparin is contraindicated. No specific reversal agent is available and termination of effect occurs as a result of renal elimination of the drug.
Of the following, the block associated with the highest blood level of local anesthetic per volume injected is the: a. epidural block b. spinal block c. intercostal block d. caudal block
C Blood concentration of local anesthetic is dependent on the total volume and concentration injected. However, with the exception of airway blocks, the intercostal block results in the highest blood levels of local anesthetic per volume injected.
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
C Current formulations of propofol contain 0.005% disodium edetate or 0.025% sodium metabisulfite to help retard the rate of microorganism growth.
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. rocuronium c. fentanyl d. succinylcholine
C Fentanyl has been shown to increase the plasma level of etomidate as well as prolong the elimination half-life of the drug.
The essential component of cardioplegia solutions is: a. mannitol b. magnesium c. potassium d. corticosteroid
C High concentrations of potassium (20 - 30 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.
The primary causative factor in the development of persistent pulmonary hypertension (PPH) in the neonate is: a. cystic fibrosis b. pregnancy-induced hypertension c. hypoxemia d. right-to-left shunting through a patent ductus arteriosus
C Hypoxia or acidosis during the early neonatal period may predispose the infant to return to fetal circulation. This serious condition, previously known as persistent fetal circulation (PFC), is currently known as persistent pulmonary hypertension (PPH). Hypoxemia and/or acidosis promotes an increase in pulmonary vascular resistance which ultimately causes right to left shunting through the ductus arteriosus, foramen ovale, or both. Shunting causes continued hypoxemia, leading to a continued increase in pulmonary vascular resistance, and a vicious cycle ensues. Primary causes of hypoxemia in the neonate include pneumonia and meconium aspiration.
In patients with a history of hypertrophic cardiomyopathy, intraoperative management should include: a. a nitroglycerine infusion b. inotropic support c. afterload reduction d. maintenance of adequate preload
C In patients with outflow obstruction, myocardial depression and maintenance of preload and afterload are desirable.
In the fetus, the percentage of cardiac output directed to the placenta is approximately: a. 10% b. 25% c. 50% d. 100%
C In the fetus, the lungs receive little blood flow. The placenta receives nearly one-half of the fetal cardiac output and is responsible for respiratory gas exchange.
The highest incidence of muscle pain following the use of succinylcholine is seen in: a. infants b. octogenarians c. outpatients d. pregnant patients
C Myalgia following the use of succinylcholine is most commonly seen in females and outpatients. Pregnancy and extremes of age seem to be protective.
The National Institute for 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
C 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).
Causes of normal-anion-gap acidosis include: a. renal failure b. starvation c. diarrhea d. lactic acidosis
C Normal-anion-gap acidosis is also called hyperchloremic acidosis and results from the selective loss of bicarbonate anion or the introduction of large amounts of chloride anion. Common causes include: diarrhea, hypoaldosteronism, renal tubular acidosis and increased intake of chloride containing acids sometimes found in hyperalimentation.
The body mass index (BMI) associated with morbid obesity is: a. > 30 b. > 35 c. > 40 d. > 45
C Overweight and obesity are classified using the BMI. Overweight is defined as a BMI > 24, obesity as a BMI > 30, morbid obesity as a BMI > 40, super obesity as a BMI > 50 and super-super obesity as a BMI > 60. BMI is calculated with the following formula: BMI = Weight (kg) / Height (meters)2
A 82-year-old female is scheduled for a total hip replacement under spinal anesthesia. She has been receiving enoxaparin for deep vein thrombosis prophylaxis. Current recommendations regarding the dosing of enoxaparin state that the drug be: a. continued without interruption as scheduled b. held for 4 - 6 hours prior to the spinal anesthetic c. held for 10 - 12 hours prior to the spinal anesthetic e. held for not less than 24 hours prior to the spinal anesthetic
C Patients receiving fractionated low-molecular weight heparin are to be considered at increased risk of spinal hematoma. Patients receiving these drugs should have the drug held for 10 - 12 hours preoperatively according to the Consensus Statement from the American Society for Regional Anesthesia and Pain Medicine.
Cholinesterase inhibitors that freely cross the blood-brain barrier include: a. neostigmine b. pyridostigmine c. physostigmine d. edrophonium
C Physostigmine is a teritary amine and has a carbamate group, but no quaternary ammonium. Therefore, it is lipid soluble and is the only clinically available cholinesterase inhibitor that freely passes the blood-brain barrier.
Pulmonary complications from advanced hepatic disease with cirrhosis include: a. an obstructive ventilatory defect b. respiratory acidosis c. increased intrapulmonary shunting d. increased functional residual capacity
C Pulmonary manifestations associated with cirrhosis include: increased intrapulmonary shunting, decreased FRC, pleural effusions, restrictive ventilatory defect and respiratory alkalosis.
Succinylcholine, 1.2 mg/kg is administered on induction. Throughout the short duration case, small doses of succinylcholine were given in anticipation of a quick closure. Upon emergence, the patient is unable to raise her head or arms, and appears generally weak. What is the most likely cause? a. not enough anticholinesterase was administered b. the nondepolarizing agent need to be reversed c. the patient has a phase 2 block d. the patient received too much opioid
C Rationale: A desensitizing succinylcholine (SCh) neuromuscular blockade or phase II block can occur after large doses of SCh administration over a prolonged period of time. Muscle cell membrane gradually repolarizes, but transmission of the neuromuscular membrane remains blocked. Clinical symptoms are apparent weakness on emergence.
The line isolation monitor: a. provides a source of ungrounded electrical power b. reduces the risk microshock c. monitors the integrity of the isolated power system d. monitors the integrity of equipment grounding wires
C The line isolation monitor continuously monitors the integrity of the isolated power system. The line isolation transformer provides ground isolation. Microshock hazards occur with the delivery of 100 microamps or less of current directly to the endocardium. These small amounts of current are well below the sensing range of the ground isolation monitor. The LIM is unable to detect a faulty grounding connection in the equipment attached to the circuit.
Mechanisms of renal compensation during acidosis include: a. decreased reabsorption of filtered bicarbonate b. decreased excretion of hydrogen ions c. increased production of ammonia d. increased elimination of carbon dioxide
C The renal response to acidemia is: • increased reabsorption of bicarbonate anion • increased excretion of hydrogen ion in the form of titratable acids • increased production of ammonia Although increased carbon dioxide elimination is a compensatory mechanism in acidemia, it is accomplished by increased alveolar ventilation.
Sensory innervation of the trachea and larynx below the vocal cords is supplied by the: a. internal laryngeal nerve b. external laryngeal nerve c. recurrent laryngeal nerve d. glossopharyngeal nerve
C 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.
In patients receiving vecuronium, the greatest augmentation of neuromuscular blockade is seen with the use of: a. isoflurane b. sevoflurane c. desflurane d. nitrous oxide
C Volatile agents decrease the nondepolarizer dosage requirements. The degree of the augmentation of blockade depends on the inhalational agent, with desflurane > sevoflurane > isoflurane > nitrous oxide.
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
C & D 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.
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
C & E 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.
Hormones released by the neurohypophysis include: (Select 2) a. thryotropin b. growth hormone c. arginine vasopressin d. adrenocorticotropic hormone e. follicle stimulating hormone f. oxytocin g. prolactin h. luteinizing hormone
C & F The neurohypophysis is another term for the posterior pituitary gland. The hormones of the neurohypophysis, oxytocin and arginine vasopressin (vasopressin, ADH), are synthesized in the hypothalamus and stored in the posterior pituitary. Stimulus for the release of arginine vasopressin arises from osmoreceptors in the hypothalamus that sense an increase in plasma osmolality.
Neuromuscular blocking agents that undergo metabolism through the Hofmann elimination include: (Select 2) a. rocuronium b. vecuronium c. atracurium d. doxacurium e. cisatracurium f. succinylcholine
C &E Atracurium and cisatracurium are bisquaternary ammonium benzylisoquinoline compounds of intermediate duration of action. They are degraded via two metabolic pathways. One of these pathways is the Hofmann reaction, a nonenzymatic degradation with a rate that increases as temperature and/or pH increases. The second pathway is nonspecific ester hydrolysis.
The dibucaine number: a.is normally less than 60% b.is a quantitative assessment of pseudocholinesterase activity c.is inversely proportional to pseudocholinesterase function d.reflects inhibition of pseudocholinesterase by dibucaine
D 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 70 - 80%. The dibucaine number is proportional to pseudocholinesterase function, but is independent of the amount of the enzyme.
Absolute contraindications to electroconvulsive therapy (ECT) include: a. congestive heart failure b. pregnancy c. myocardial infarction 5 months prior to therapy d. increased intracranial pressure
D Absolute contraindications to ECT include recent MI (usually < 3 months), recent stroke (< 1 month), intracranial mass, or increased ICP from any cause. Relative contraindications include angina, CHF, significant pulmonary disease, bone fractures, osteoporosis, pregnancy, glaucoma and retinal detachment.
Failure of the scavenging system due to obstruction could cause: a. a hypoxic gas mixture b. a low pressure alarm c. carbon dioxide absorbent failure d. increased positive pressure within the circuit
D Obstruction of scavenging pathways can cause excessive positive pressure in the breathing circuit, and barotrauma can occur.
Opioids currently NOT approved for epidural or intrathecal use include: a. fentanyl b. sufentanil c. morphine d. remifentanil
D Remifentanil is prepared in a solution of glycine, a known inhibitory neurotransmitter. Currently, remifentanil is not approved for epidural or intrathecal use.
In the flow-volume loops below, restrictive lung disease is best represented by: A B C D
D Restrictive disease is best represented by flow-volume loop D, which demonstrates reductions in TV, TLC and FRC.
Pancreatic somatostatin producing cells in the Islets of Langerhans are: a. alpha cells b. beta cells c. gamma cells d. delta cells
D The Islets of Langerhans are comprised of four cell types: alpha cells producing glucagon, beta cells producing insulin, delta cells producing somatostatin and PP cells producing pancreatic polypeptide.
Correct statements regarding cerebral metabolism include: a. the brain can only utilize glucose as an energy source b. forty percent of brain glucose consumption is anaerobically metabolized c. hyperglycemia can reduce the damage from focal hypoxic injury d. the adult brain consumes approximately 50 ml/min of oxygen
D The adult brain consumes about 20% of the total body oxygen (50 ml/min). Neuronal cells normally utilize glucose as their energy source, but can also utilize ketone bodies and lactate. Hyperglycemia has been shown to worsen global and focal hypoxic brain injury.
The highest level of protein binding is seen with: a. procaine b. lidocaine c. mepivacaine d. bupivacaine
D The physicochemical property that determines the duration of action of a local anesthetic is lipid solubility, which is directly correlated with plasma protein binding. Bupivacaine and levobupivacaine have the highest degree of protein binding (97%).
Anesthetic management of the patient with the pressure-volume loop shown below (yellow) should include: a. maintenance of a heart rate of < 50 b. spinal or epidural anesthesia if possible c. vasodilator therapy d. treatment of hypotension with phenylephrine
D This pressure-volume loop is indicative of aortic stenosis. Patients with severe aortic stenosis have a fixed stroke volume, and cardiac output is rate dependent. Both tachycardia and bradycardia are poorly tolerated. Vasodilation from regional anesthesia or volatile agents may precipitate severe hypotension. Treatment of hypotension should be prompt and accomplished with small doses of an alpha-stimulant such as phenylephrine.
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 cmH2O c. 25 psi d. 50 psi
D After proper location of the catheter is confirmed by aspiration air, jet ventilation may be achieved with intermittent pulses of oxygen at 50 psi.
Re-order the list of inhaled agents below from highest vapor pressure to lowest (Highest vapor pressure agent at top of list): Sevo Des Nitrous Oxide Iso
Nitrous Oxide Des Iso Sevo At 20o C, the highest vapor pressure of the inhaled agents is possessed by nitrous oxide (38,700 mm Hg), followed by desflurane (669 mm Hg), isoflurane (238 mm Hg) and sevoflurane (157 mm Hg).
During rapid-sequence induction, cricoid pressure is applied to reduce the incidence of regurgitation. After loss of consciousness, the recommended amount of downward force applied to the cricoid cartilage is:
Using cricoid yolk studies, the optimum force necessary to effectively occlude the esophagus without obstruction of the trachea is between 30 and 44 Newtons (3.0 - 4.4 kg). It is recommended that 2 kg of force be applied prior to loss of consciousness and that pressure be increased to 4 kg of force after loss of consciousness.
A fresh E-cylinder of oxygen: a. contains more liters of gas than an E-cylinder of nitrous oxide b. contains about 90% liquid oxygen and 10% oxygen as a gas c. contains about 660 liters of oxygen when at sea level d. has a lower pressure than the pipeline oxygen supply
a A fresh E-cylinder of oxygen contains about 660 liters of oxygen and is pressurized to 1900 psi.
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
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.
