Cardiovascular

Question 1

A transesophageal echocardiogram is performed. The red arrow in the image points to a region of tissue that displays severe hypokinesis. Which of the following coronary arteries is MOST likely involved?

Answer 1

The transesophageal echocardiography (TEE) image displayed in the question is a transgastric short-axis view of the left ventricle (LV) at the midpapillary level. The red arrow is pointing toward the anterior wall of the LV, which is most commonly perfused by the left anterior descending (LAD) artery.

Posteromedial papillary muscle rupture is more common than anterolateral papillary muscle rupture because of the single blood supply (right coronary artery or left circumflex artery) of the former and the dual blood supply (left anterior descending artery and left circumflex artery) to the latter.

Question 2

Which of the following statements comparing roller and centrifugal pumps used in cardiopulmonary bypass is TRUE?

Answer 2

Centrifugal pumps are preferred to roller pumps in cardiopulmonary bypass circuits due to less blood element destruction, lower line pressures, lower risk of air emboli, and elimination of tubing wear and spallation.
Centrifugal pump blood flow varies depending on pump preload and afterload.
Both roller and centrifugal pumps can deliver adequate systemic pressure during CPB periods via non-pulsatile flow.

Question 3

Which of the following arrows MOST accurately represents the effect of furosemide in the setting of systolic heart failure?

Answer 3

Diuretics improve symptoms of CHF by reducing cardiac filling pressures along the same ventricular function curve. They do not directly improve inotropy or stroke volume.

TrueLearn Insight : Loop diuretics also have mild pulmonary vasodilatory properties and are useful in the setting of right ventricular failure to reduce right ventricular preload and afterload.

Question 4

This abnormal CVP waveform is MOST indicative of which of the following cardiac conditions?

Answer 4

a – atrial contraction
c – tricuspid valve bulging into right atrium during right ventricle isovolemic contraction
x – tricuspid valve descends into right ventricle with ventricular ejection
v – venous return to the right atrium
y – atrial emptying into right ventricle through open tricuspid valve

Atrial fibrillation: loss of a wave
AV dissociation: cannon a wave
Tricuspid regurgitation: tall c and v waves, loss of x descent
Tricuspid stenosis: tall a and v waves, minimal y descent
RV ischemia: tall a and v waves, steep x and y descent, M or W configuration
Pericardial constriction: tall a and v waves, steep x and y descent, M or W configuration
Cardiac tamponade: dominant x descent, minimal y descent

Question 5

You are caring for a patient undergoing an awake carotid endarterectomy with superficial cervical plexus block. The surgeon is thirty minutes into the procedure when you notice an abrupt decrease in blood pressure and heart rate. The patient denies any pain. Which of the following should occur first?

Answer 5

The baroreceptor reflex (carotid sinus reflex) helps maintain arterial blood pressure through a negative feedback loop. Sudden onset of bradycardia during surgical manipulation near the baroreceptors or vagal nerve should prompt immediate cessation of surgical stimulation.
Infiltration at the carotid bifurcation with 1% lidocaine usually prevents further episodes however it may increase the incidence of intraoperative and postoperative hypertension thus routine administration of local at the carotid bifurcation is not recommended (D). Administration of ephedrine and/or glycopyrrolate may be needed if cessation of stimulation does not fix the hemodynamic changes however it should not be the first line treatment (A, B).

Question 6

According to the ACC/AHA 2014 Guidelines on Perioperative Cardiovascular Evaluation, which of the following patient descriptions has the strongest recommendation for perioperative beta-blocker therapy?

Answer 6

The strongest recommendations (Class 1) for perioperative use of beta blockers are for patients undergoing any type of surgery who are already taking preoperative beta blockers.

Question 7

For which of the following patients is preoperative beta-blocker therapy most likely indicated?

Answer 7

Patients with multiple clinical risk factors (3 or more) for coronary artery disease undergoing high risk surgery should be started on beta blockade.
Clinical risk factors for coronary disease include:
- A history of ischemic heart disease
- Congestive heart failure
- History of stroke
- Diabetes
- Chronic kidney disease.

Question 8

Which of the following coincides with the c-wave on central venous pressure waveform?

Answer 8

The QRS complex on the ECG and the c-wave on the central venous pressure tracing both coincide with ventricular contraction.
The QRS complex on the ECG correlates with the c-wave on the CVP waveform, mitral valve closure, and the beginning of aortic valve opening with an increase in ventricular pressure. The end of the T wave on the ECG correlates with the v-wave on the CVP waveform, aortic valve closure, and the beginning of mitral valve opening with a decrease in ventricular pressure.

Question 9

A 63-year-old male is found to have concentric hypertrophy of the left ventricle on echocardiography. Which of the following BEST describes the benefit of ventricular hypertrophy?

Answer 9

Wall tension (T) = (P * r) / (2 h)
Where P is the pressure within the ventricle, r is the radius of the ventricle, and h is the thickness of the ventricular wall. The hypertrophied ventricle is not as compliant due to increased diastolic pressures in the ventricle.  This leads to a decrease in preload, and the hypertrophied ventricle is now more dependent on atrial contraction to maintain LVEDV. The three main determinants of myocardial oxygen demand are: wall tension, heart rate, and contractility.

Question 10

A patient presents to the Emergency Department in cardiac arrest with Advanced Cardiac Life Support (ACLS) measures being started. An endotracheal tube is placed but continuous waveform capnography is unavailable. Continuous chest compressions are begun. Which of the following is the most appropriate method for rapidly, and reliably, confirming correct endotracheal placement in this cardiac arrest patient?

Answer 10

Primary confirmation of endotracheal tube placement is based on clinical assessment. Secondary confirmation of endotracheal tube placement is achieved with ETCO2 detection (qualitative, quantitative, or continuous) or an esophageal detector device.

TrueLearn Insight : Chest compressions and defibrillation are the most important aspects of ACLS. Advanced airway devices can typically be deferred. Hyperventilation after endotracheal tube placement has been shown to worsen outcomes. Aim for one breath every 5-6 seconds (10-12 per minute). Each breath should be delivered over 1 second and achieve visible chest rise.

Question 11

A 62-year-old male with prostate cancer is scheduled for radical prostatectomy. Preoperative cardiac catheterization shows severe single vessel disease amenable to percutaneous intervention. A decision is made to proceed with PCI and stenting, and schedule the radical prostatectomy for 4-6 weeks later. According to the ACC/AHA guidelines, which of the following combinations of type of stent and perioperative antiplatelet therapy would be the MOST appropriate?

Answer 11

According to the 2016 ACC/AHA guidelines, patients undergoing PCI for stable ischemic heart disease should receive dual antiplatelet therapy for at least one month after BMS and at least six months after DES.

Question 12

Which of the following is TRUE regarding myocardial ischemia?

Answer 12

Acute ST-elevation represents transmural myocardial injury whereas ST depression represents subendocardial ischemia. Recognition is important as treatment strategies between the two are different.

Question 13

What is the MOST important determinant regulating the myocardial oxygen supply-demand relationship?

Answer 13

Changes that increase oxygen supply:

• Increased hemoglobin concentration
• Lower afterload and/or preload
• Decreased contractility
• Decreased heart rate

Changes that decrease demand:

• Decreased heart rate
• Decreased afterload and/or preload
• Decreased contractility

Question 14

What change will MOST likely occur to point X on the Frank-Starling curve after dosing phenylephrine?

Answer 14

Phenylephrine is an alpha-1 agonist that causes both arterial and venous constriction, resulting in increased afterload and preload, respectively. The increased preload (end-diastolic volume) can result in increased stroke volume (cardiac output) if the patient is volume dependent (steep portion of the Frank Starling curve). Patients who are on the flat portion of the curve (volume independent or CHF) may see a decrease in cardiac output with increased end-diastolic volume. In general, end-diastolic volume increases with phenylephrine.

Question 15

Which of the following agents is most likely responsible for the effect described by arrow D?

Answer 15

The Frank-Starling relationship indicates that the force the ventricle is able to generate (e.g., CO, SV) is dependent upon loading conditions (e.g., EDV, end-diastolic pressure). Milrinone is a PDE3i which leads to improved inotropy AND vasodilation (I+V). It causes a leftward and upward shift of the Frank-Starling curve.

Question 16

A 73-year-old male presents with dyspnea and pulmonary edema. He is admitted to the intensive care unit for stabilization. He has a decrescendo diastolic murmur as well as an increased pulse pressure. He also demonstrates bisferiens pulse waves. Which of the following drugs promotes favorable hemodynamics for this patient’s valvular pathology?

Answer 16

Aortic regurgitation occurs when blood returns to the left ventricle from the aorta because of an incompetent aortic valve. The regurgitation of blood will lower diastolic blood pressure and cause dilation of the left ventricle. To compensate for the regurgitant flow, the left ventricle hypertrophies and increases its stroke volume. Medical therapy for aortic regurgitation is mainly targeted at decreasing afterload with drugs like nitroprusside. Additionally, the ideal heart rate for a patient with aortic regurgitation is high normal to decrease the amount of time regurgitation can occur.

Question 17

Which of the following drugs is metabolized by red blood cell esterases?

Answer 17

Esmolol is a short-acting, selective β1-blocker that is rapidly metabolized by red blood cell (RBC) esterases with a short half-life of 9 minutes.

Question 18

Which of the following statements is true regarding vasopressin compared to epinephrine?

Answer 18

Vasopressin stimulates water retention and peripheral vasoconstriction while improving MAP and cerebral and coronary perfusion. Vasopressin dramatically increases SVR and afterload which potentially reduces CO.

Question 19

Which of the following patients MOST likely requires infective endocarditis prophylaxis prior to surgery?

Answer 19

The high-risk factors are:
1) Prosthetic heart valves
2) Prior history of infective endocarditis
3) Unrepaired cyanotic congenital heart disease
4) Completely repaired congenital heart defect (the first six months after procedure)
5) Repaired congenital heart disease with residual defect
6) Valvular disease in a transplanted heart
The high-risk procedures are:
1) Dental work – highest risk for infective endocarditis in procedures that involve gingival tissue manipulation or perforation of the oral mucosa. For example, tooth extractions, or drainage of a dental abscess. However, routine dental cleaning is not a high-risk procedure that requires prophylaxis.
2) Respiratory tract procedures that warrant prophylaxis are those involving incision/biopsy of the respiratory tract mucosa. This includes tonsillectomy, adenoidectomy, and bronchoscopy with biopsy.
3) Skin or musculoskeletal tissue procedures

Question 20

Which of the following is a known side effect of amiodarone?

Answer 20

Important side effects of amiodarone include bradycardia, hypotension, atrioventricular node block, prolonged QT interval, pulmonary toxicity (with a pulmonary fibrosis appearance), hypothyroidism, life-threatening hyperthyroid storm, blue-grey skin deposits, and elevated liver function markers.

Question 21

The following electrocardiogram is in your patient’s preoperative chart. Which of the following medical conditions does the patient MOST LIKELY have?

Answer 21

Multifocal atrial tachycardia (MAT) is defined by a heart rate greater than 100 and three or more distinct morphologies of the P wave on an electrocardiogram or rhythm strip. It is commonly seen in patients with pulmonary and cardiac pathologies, especially those resulting in atrial distention and pulmonary HTN. COPD exacerbation is the most common cause.

Question 22

A 40-year-old male with history of alcoholism suffered a fall with loss-of-consciousness after a severe binge drinking episode. His injuries include a right open tibial plateau fracture and right distal radius fracture. He has no other injuries and has been in the ICU for the past 24 hours. He has been volume resuscitated with 5 liters of normal saline and 4 units of packed red blood cells. His hemoglobin is now 9.0 mg/dL and lactate has decreased back to normal range. He is coming to the operating room for fracture repairs.

Induction with propofol, fentanyl, and rocuronium is performed and the patient is intubated. He becomes hypotensive with a blood pressure of 80/50 mm Hg. He is given a liter bolus of normal saline and multiple boluses of phenylephrine. Lactate has now increased to 4 mg/dL and the patient remains hypotensive. A TEE is inserted and shows global LV hypokinesis and dilation with no regional abnormalities or valvular dysfunction. Right ventricular function appears normal. Administration of epinephrine at 0.02 mcg/kg/min would cause WHICH of the following shifts to occur on the graph below?

Answer 22

A shift in the Frank-Starling curve up or down depicts changes in contractility, with upward shifts showing positive inotropy and downward shifts suggesting negative inotropy.

Question 23

When used alone, which of the following leads is the MOST SENSITIVE for detecting myocardial ischemia?

Answer 23

Intraoperative monitoring of Leads II and V4 is the preferred lead combination as it allows for rhythm monitoring and is sensitive for myocardial ischemia. Alone, V5 has the highest sensitivity for myocardial ischemia, however, this is not recommended for intraoperative monitoring.

Question 24

A 74-year-old male is noted to have a large R wave in lead V1 on an ECG. Which of the following conditions would NOT be associated with this finding?

Answer 24

The following diagnoses should be considered in patients with a large R wave in lead V1:

1) Right ventricular hypertrophy
2) Posterior wall MI
3) Wolff-Parkinson-White syndrome
4) Muscular dystrophy
5) Right atrial enlargement
6) Right ventricular strain with ST-T wave abnormalities

Question 25

Which of the following drugs resembles brain natriuretic peptide and causes vasodilation, diuresis, and natriuresis?

Answer 25

Nesiritide is a recombinant form of human brain natriuretic peptide that is normally produced by ventricular myocardium to counter hyperdynamics and/or hypervolemia. Nesiritide’s only current recommended indication is in the treatment of acutely decompensated congestive heart failure.

Question 26

Which of the following would MOST likely be visualized on the electrocardiogram in a patient with a dual-chamber pacemaker who is completely pacemaker dependent?

Answer 26

Placement of leads in the right atrium and ventricular septum of the right ventricle is common in patients with dual-chamber pacemakers. This leads to a spike followed by a P wave and a left bundle branch pattern

Question 27

According to the 2014 American College of Cardiology and American Heart Association (ACC/AHA) perioperative cardiovascular guidelines, which of the following is considered an active cardiac condition for which elective surgery should be delayed?

Answer 27

Active Cardiac Conditions: Unstable coronary syndromes - Unstable angina (class III or IV) - Active myocardial infarction (occurring within the last 7 days) - Recent myocardial infarction (occurring within the past 8 to 30 days) Decompensated congestive heart failure - New York Heart Association (NYHA) class IV - New onset or worsening dyspnea Significant arrhythmias - High-grade atrioventricular block - Symptomatic ventricular arrhythmias - Uncontrolled supraventricular tachycardia including atrial fibrillation - Symptomatic bradycardia - New ventricular tachycardia Severe valvular disease - Severe aortic stenosis - Symptomatic mitral stenosis

Question 28

Which of the following β-blockers is cleared via the kidneys unchanged and causes minimal bronchoconstriction in patients with reactive airway disease?

Answer 28

Atenolol is a selective β1-blocker that is cleared by the kidneys unchanged and at therapeutic doses has minimal β2 bronchoconstriction in patients with reactive airway disease. TrueLearn Insight : The cardioselective (β1) blockers may be remembered utilizing the mnemonic “BEAM” (Bisoprolol, Esmolol, Atenolol, and Metoprolol).

Question 29

Which of the following methods is the quickest and most reliable to diagnose proper placement of the central line thin-walled needle or catheter prior to vessel dilation?

Answer 29

Pressure monitoring is required prior to vascular dilation when placing a central venous catheter. There are a variety of approaches. The American Society of Anesthesiologists practice advisory has stepwise guidelines.

Question 30

Aging causes which of the following physiologic changes?

Answer 30

Nervous System - Decreased gray/white matter - Decreased neurotransmitters (acetylcholine, dopamine) - Decreased epidural space - Decreased CSF volume - Increased permeability of dura mater Cardiovascular System - Decreased ventricular compliance - Decreased beta-receptor responsiveness - Increased sympathetic nervous system activity - Increased stiffness of large arteries Respiratory System - Decreased vital capacity - Increased residual volume - Increased closing capacity - Increased anatomic dead space - Increased lung compliance - Increased pulmonary vascular resistance Hepatic System - Decreased hepatic blood flow

Question 31

Which of the following medications causes the greatest reduction in preload?

Answer 31

Nitroglycerin is a potent direct-acting venous vasodilator that results in preload reduction and coronary vasodilation. Nicardipine is an arteriolar vasodilator that primarily lowers afterload while nitroprusside decreases both preload and afterload. Carvedilol is a nonselective beta blocker with some alpha blocker activity. TrueLearn Insight : Nicardipine, nitroglycerin, and sodium nitroprusside inhibit hypoxic pulmonary vasoconstriction.

Question 32

Which of the following changes is depicted by a transition to the dotted line?

Answer 32

Positive lusitropy. This is illustrated on the myocardial pressure-volume loop as a reduction in the slope and a rightward shift of the diastolic filling phase

Question 33

A 64-year-old male presents to the Emergency Department complaining of chest pain, sweating, and dizziness. He has a heart rate of 40 and his electrocardiogram shows complete heart block. This is MOST likely caused by blockage of what coronary artery?

Answer 33

About 85% of the population is right-dominant with the RCA giving rise to the PDA. The AV node is supplied by a branch of the RCA in right-dominant patients and complete heart block is most commonly caused by a myocardial infarction involving the RCA.

Question 34

You are seeing a 66-year-old man in the preoperative anesthesia clinic who is scheduled for coronary artery bypass grafting. His past medical history is significant for coronary artery disease with unstable angina, chronic kidney disease, hypertension, diabetes, and a 40-pack-year history of smoking. He tells you that he had a “mini-stroke” 5 years ago where he lost all feeling on his left side but the symptoms resolved within 24 hours. Besides being overweight, there are no abnormalities on physical exam. His has a 4 MET functional capacity. ``` His physical exam and relevant vitals are: Height: 172.0 cm Weight: 73.7 kg BSA: 1.80 m2 Blood pressure: 125/67 mmHg Initial pulse: 66 bpm ``` His ECG shows evidence of a previous Q wave infarction, age indeterminate. He underwent an echocardiogram that showed the following: Ejection fraction: 55% Wall motion: mild inferior wall hypokinesis, moderate apical hypokinesis LV dilation: mild global dilation Mean Ao-LV gradient: 45 mm Hg Aortic valve area: 0.7 cm2 ``` His coronary angiography results are as follows: RV: 32/7, EDP 10 PA: 32/17, mean = 20 PCW: a = 8, v = 12, mean = 10 Systemic BP: 120/78, mean = 95 Segment Stenosis Mid RCA 30% Mid LAD 70% Dist LAD 30% Left Main 60% Left CX normal ``` What is the next appropriate test to order before this patient undergoes surgery?

Answer 34

Carotid artery duplex scanning is reasonable in patients with a high risk profile. Features indicative of a high risk profile are age greater than 65, left main coronary artery disease, peripheral vascular disease, hypertension, diabetes, smoking, and neurovascular pathology as evidenced by previous TIA and/or stroke.

Question 35

Which of the following drugs decreases blood pressure PRIMARILY by afterload reduction and has MINIMAL effect on preload?

Answer 35

Nicardipine reduces afterload and blood pressure via arteriolar vasodilation. Because of the effect of nicardipine on primarily the arteriolar side, the practitioner’s ability to titrate blood pressure steadily is improved compared to use of an arteriovenous dilator, such as nitroprusside.

Question 36

Which of following clinical scenarios warrants the use of antibiotic prophylaxis for infective endocarditis?

Answer 36

Antibiotic prophylaxis with dental procedures is reasonable only for patients with cardiac conditions associated with the highest risk of adverse outcomes from endocarditis, including: 1) Prosthetic cardiac valve or prosthetic material used in valve repair (A) 2) Previous endocarditis 3) Congenital heart disease (CHD) ONLY in the following categories: - Unrepaired cyanotic congenital heart disease, including those with palliative shunts and conduits - Completely repaired congenital heart disease with prosthetic material or device during the first six months after the procedure* - Repaired congenital heart disease with residual defects at the site or adjacent to the site of a prosthetic patch or prosthetic device (which inhibit endothelialization) 4) Cardiac transplantation recipients with cardiac valvular disease

Question 37

A 59-year-old male is scheduled for carotid endarterectomy under general anesthesia. Carotid Doppler examination reveals a unilateral high-grade stenosis. He is asymptomatic, active, and regularly plays tennis without problems. Which of the following is the next BEST step in preoperative evaluation?

Answer 37

Preoperative algorithms help anesthesia providers make clinical decisions in the preoperative period regarding the need for further testing. The new guidelines, published in 2014, make use of surgical calculators to determine the patient's risk of MACE. The guidelines also make recommendations on when to obtain other tests such as electrocardiograms, echocardiograms and cardiopulmonary tests. If MACE < 1% and there is no acute coronary syndrome, then no further testing is needed and the patient may proceed to surgery.

Question 38

A 55-year-old male in the intensive care unit suffers a cardiac arrest. He was initially found to be in ventricular fibrillation and preparation begins for defibrillation. Which of the following will BEST optimize defibrillation?

Answer 38

Defibrillation success decreases with arrhythmia time. Factors that improve defibrillation include quick electrode gel, biphasic defibrillation, and larger electrodes.

Question 39

Which of the following will improve myocardial oxygen supply and decrease myocardial oxygen demand?

Answer 39

Myocardial oxygen supply is determined by the arterial oxygen content of blood and coronary perfusion time and pressure. Myocardial oxygen demand is determined by myocardial work which is primarily dependent on heart rate and wall tension. Heart rate is a unique variable in that it plays a role in determining both myocardial oxygen supply and demand. TrueLearn Insight : The left ventricle is perfused only during diastole. The right ventricle is perfused throughout the cardiac cycle but receives its greatest perfusion during peak/late systole and early diastole.

Question 40

A patient presents to preoperative clinic after undergoing drug-eluting stent placement 100 days ago. He is maintained on dual antiplatelet therapy and awaits cataract surgery, which cannot be performed while the patient takes an antiplatelet agent. His ophthalmologist prefers to operate as soon as possible. The 2016 American College of Cardiology/American Heart Association guidelines are reviewed. When should his surgery be scheduled?

Answer 40

ACC/AHA 2016 guidelines recommend a minimum duration of DAPT before elective noncardiac surgery (30 days after bare-metal stent placement and 6 months after drug-eluting stent placement) to prevent stent thrombosis during the period of stent re-endothelialization. If risk of delaying surgery exceeds risk of stent thrombosis, surgery may be performed only 3-6 months after drug-eluting stent implantation. TrueLearn Insight : During the preoperative evaluation, the presence, type (drug-eluting vs. bare-metal), location, time of placement, and original indication for coronary stents should be determined. Preoperative recommendations regarding perioperative DAPT are best made in collaboration with a cardiologist and the surgeon.

Question 41

Spinal anesthesia is performed for a transurethral resection of the prostate in a 76-year-old male with severe aortic stenosis. Preanesthetic vital signs are: blood pressure 148/76 mm Hg and heart rate 64 bpm. Shortly after the spinal is completed, blood pressure is 88/42 mm Hg, heart rate is 72 bpm, and ST depressions are noted in the anterolateral leads. Which of the following is the MOST appropriate drug for treatment in this situation?

Answer 41

Alpha-1 adrenergic agonists such as methoxamine and phenylephrine are ideal for treatment of hypotension in patients with severe AS, particularly in the setting of myocardial ischemia. They increase afterload which improves CPP and the reflex heart rate reduction decreases myocardial oxygen demand.

Question 42

Which of the following characteristics makes epinephrine a medication of choice in ventricular fibrillation?

Answer 42

Epinephrine is used during cardiac arrest for its alpha-mediated vasoconstriction. Escalating doses above the guidelines has not been shown to improve survival or neurologic outcome after cardiac arrest.

Question 43

Tachycardia would MOST likely lead to which of the following changes?

Answer 43

Increased physiological stress, cardiac activity, and metabolic demand will lead to increased myocardial oxygen consumption. Myocardial oxygen demand must be met by an increase in arterial oxygen supply via coronary blood flow.

Question 44

A pulmonary artery catheter is placed in a 72-year-old intensive care unit patient and shows a cardiac index of 1.1 L/min/m^2 and a pulmonary artery wedge pressure of 28 mm Hg. Which of the following is the MOST likely diagnosis?

Answer 44

Cardiogenic shock (either systolic or diastolic associated) will lead to an increase in CVP and PAWP. There will be a decrease in cardiac index, blood pressure, and mixed venous oxygen saturation. Systemic vascular resistance and heart rate may be unchanged or increased.

Question 45

A 38-year-old male develops non-Hodgkin lymphoma. He is undergoing m-BACOD treatment, consisting of methotrexate, bleomycin, doxorubicin, cyclophosphamide, vincristine, and dexamethasone. After several sessions he begins to complain of swelling in his extremities and dyspnea on exertion. An echocardiograph reveals an ejection fraction of 20-25%. Which of the following is the MOST likely cause of this patient’s condition?

Answer 45

Doxorubicin can cause significant cardiomyopathy in a dose dependent fashion. Bleomycin is associated with pulmonary toxicity and patients undergoing anesthesia should not receive high FiO2. Immunosuppression necessitates meticulous aseptic technique. Hepatotoxicity and nephrotoxicity are not uncommon with chemotherapeutic agents. Cyclophosphamide interacts with succinylcholine, increasing apnea risk. NSAIDs should be avoided if methotrexate is used. Regional anesthesia should be re-considered for patients with neuropathy secondary to vincristine or cisplatin.

Question 46

A 66-year-old male is scheduled for emergency exploratory laparotomy and combined burr hole drainage of subdural hematoma after a motorcycle accident. His medical history is significant for atrial fibrillation, hypertension, and hypothyroidism. His home medications include warfarin, digoxin, levothyroxine, and aspirin. Which of the following medications can cause an increase in the sensitivity to the effect and toxicity of digoxin, without affecting the plasma levels of digoxin?

Answer 46

Hypokalemia potentiates the effect and toxicity of digoxin, and potassium should be monitored in patients receiving potassium-losing diuretics such as furosemide.

Question 47

The patient’s wife indicates he has not taken his medications today. Vital signs include: BP 79/44, HR 124, pulse oximetry 95%, FiO2 0.8, and urine output 150-200 mL/hr. Which of the following medication will MOST likely treat this condition?

Answer 47

Vasopressin may be used as a first-line vasopressor for neurogenic diabetes insipidus following TBI.