CARDIAC SURGERY CSC ACTUAL FINALS QUESTIONS
AND ANSWERS SURE A+
✔✔Your postoperative CABG patient has atrial fibrillation with a ventricular rate in the
40's. Atrial and ventricular epicardial pacing wires are in place. Which pacing mode is
indicated to increase the heart rate in this patient:
A. DDD.
B. VVI.
C. DVI.
D. AAI. - ✔✔B. Atrial fibrillation with a slow ventricular response requires VVI pacing to
maintain an adequate ventricular rate. Atrial pacing and sensing are ineffective in atrial
fibrillation, therefore any mode that utilizes atrial pacing or atrial sensing is not indicated.
The AAI, DVI, and DDD modes all utilize atrial pacing or sensing and are not indicated
for this patient.
✔✔Inotropic support is often needed for the first few hours following CABG surgery
when there is left ventricular dysfunction present. Which of the following drugs are
appropriate for inotropic support:
A. Nitroglycerine or nitroprusside.
B. Norepinephrine or vasopressin.
C. Milrinone, dobutamine, dopamine, or epinephrine.
D. Esmolol, metoprolol, or nicardipine. - ✔✔C. Milrinone, dobutamine, dopamine, and
epinephrine all increase contractility. Milrinone is also a vasodilator so would be
indicated when inotropic support is needed in the presence of a high SVR. Dobutamine,
dopamine, and epinephrine all have beta adrenergic effects to increase contractility.
Epinephrine is often the preferred inotropic agent because it causes less tachycardia
than dopamine or dobutamine and also has some peripheral vasoconstrictor effects that
can help support the blood pressure.
Nitroglycerin and nitroprusside are both vasodilators with no inotropic effect.
Nitroglycerin is primarily a venous dilator and is used for preload reduction.
Nitroprusside has both venous and arterial vasodilating effects with somewhat more
arterial effect and is used to manage postoperative hypertension.
Esmolol and metoprolol are beta blockers and nicardipine is a calcium channel blocker.
Beta blockers and calcium channel blockers are negative inotropic drugs and decrease
,contractility. Nicardipine is also a peripheral vasodilator and can be used to treat
postoperative hypertension.
✔✔Myocardial stunning can be a cause of postoperative left ventricular dysfunction.
Which of the following best describes stunning:
A. Normal ventricular function in the presence of excessively high afterload.
B. Intraoperative ischemia resulting in permanent left ventricular dysfunction.
C. Transient ischemia followed by myocardial reperfusion and normal left ventricular
function.
D. Transient ischemia followed by myocardial reperfusion and left ventricular
dysfunction of limited duration. - ✔✔D. Myocardial stunning is transient post ischemic
LV dysfunction that occurs after total or significant reduction of coronary blood flow,
followed by reestablishment of coronary flow. The LV dysfunction is of limited duration
and improves over time with support from inotropic agents or mechanical assist (i.e.
IABP). In the cardiac surgery patient, stunning can occur when coronary flow is
disrupted by CPB and then reestablished at the end of the procedure and is one of the
causes of postoperative low cardiac output syndrome.
✔✔Which of the following is true concerning the use of aspirin following CABG surgery:
A. ASA is contraindicated because of the increased risk of bleeding from new grafts.
B. ASA is indicated for all CABG patients because of its antiplatelet effects and for
secondary prevention of coronary disease.
C. ASA is indicated for patients receiving arterial grafts but not venous grafts.
D. ASA is indicated for all CABG patients as an analgesic for postoperative pain control.
- ✔✔C. The use of ASA in the early postoperative period is used to offset platelet
activation and aggregation in the early postop period. ASA may result in improved graft
patency; decrease the incidence of perioperative MI, stroke, and acute kidney injury;
and reduce mortality. It is recommended that ASA be started within 6 hours
postoperatively (after mediastinal bleeding has stopped) and continued indefinitely for
secondary prevention in all CABG patients who do not have a contraindication to ASA.
✔✔Atrial fibrillation is particularly dangerous in which of these patients:
A. Patient with mitral valve replacement for mitral stenosis.
B. Patient who had 5-vessel CABG.
C. Patient with aortic valve replacement for aortic stenosis.
D. Patient with preoperative LV dysfunction. - ✔✔C. Aortic stenosis causes left
ventricular hypertrophy with a stiff noncompliant LV and diastolic failure. A noncompliant
LV depends on atrial kick for adequate preload and stroke volume. Sinus rhythm or AV
pacing is especially important in this patient to maintain AV synchrony and adequate
preload. Atrial fibrillation results in a loss of atrial kick and can lead to profound
hemodynamic deterioration.
Atrial fibrillation can occur in any post operative cardiac surgery patient and is especially
common in mitral valve disease because of the increased atrial pressure and/or volume
that occurs. However, it is better tolerated in patients who do not have LV diastolic
dysfunction or LV hypertrophy.
,✔✔Your patient has had an aortic valve replacement for severe aortic stenosis. She has
been in sinus rhythm at a rate of 70 with adequate hemodynamics but has now gone in
to 3rd degree AV block with a junctional rhythm at a rate of 40 beats per minute and is
hypotensive. Atrial and ventricular epicardial pacing wires are present. What type of
pacing would be best in this patient:
A. DDD.
B. DVI.
C. AAI.
D. VVI. - ✔✔A.A patient with aortic stenosis has a stiff noncompliant LV that depends
on atrial kick for much of its preload to maintain an adequate stroke volume. DDD
pacing means that the pacemaker paces atria and ventricles (first D), senses in atria
and ventricles (second D), and inhibits or triggers pacing depending on whether atrial or
ventricular activity was sensed (third D). The DDD pacing mode allows the pacemaker
to sense the patient's own P waves and paces the ventricle in response to those P
waves, thus maintaining AV synchrony and improving LV preload. The DDD pacing
mode always maintains AV synchrony regardless of what the underlying rhythm is.
This patient is in third degree block, so pacing the atrium alone (AAI) will do no good
since there is no AV conduction present.
VVI pacing would increase the ventricular rate but would not maintain AV synchrony.
DVI pacing paces both the atria and the ventricles but only senses in the ventricle,
therefore it would not sense her intrinsic P waves but would pace both atria and
ventricles at the minimum rate set in the pacemaker. Since this patient has an adequate
sinus rhythm, the DDD mode is better because it will allow for atrial sensing and pace
the ventricle in response to her intrinsic P waves. Both DDD and DVI modes preserve
AV synchrony.
✔✔Antifibrinolytic drugs used to reduce intraoperative or postoperative blood loss
include:
A. Amicar (aminocaproic acid) and cyclokapron (tranexaminic acid).
B. Aprotinin and amicar.
C. tPA (tissue plasminogen activator) and clopidogrel.
D. Protamine and vitamin K. - ✔✔A. Amicar and cyclokapron are antifibrinolytic drugs
that inhibit the breakdown of fibrin. They are used in both on- and off-pump cases to
reduce intraoperative bleeding and can be used in postoperative patients who are
bleeding excessively. Aprotinin is another antifibrinolytic drug that was commonly used
to reduce blood loss but it is no longer being manufactured because of the risk of renal
dysfunction and increased mortality.
Tissue plasminogen activator (tPA) is a thrombolytic drug used to break down clots in
acute coronary syndromes and acute ischemic stroke. Bleeding is a common side effect
of tPA and it is not indicated in cardiac surgery patients.
Clopidogrel is a P2Y12 receptor inhibitor that inhibits platelet activation and is used in
acute coronary syndromes and ischemic stroke. Bleeding is a side effect of P2Y12
inhibitors and they are not used in patients who are bleeding.
Protamine is used to reverse heparin at the end of a cardiac surgical procedure and
therefore is used to reduce the incidence of bleeding, but it is not an antifibrinolytic
, agent. Vitamin K is used to reverse the effects of warfarin and is not an antifibrinolytic
agent.
✔✔When you turn your post CABG patient you notice about 100 ml of dark blood
dumping through the chest tubes. You should now do which of the following:
A. Ignore it because it is normal for dumping to occur with position changes.
B. Immediately notify the surgeon because this indicates acute and excessive bleeding
that could require surgical intervention.
C. Evaluate blood pressure and hemodynamic values and give a 500 cc fluid bolus.
D. Assess blood pressure and hemodynamic values to evaluate patient's condition and
observe chest tubes for additional drainage once patient is repositioned. - ✔✔D. A
significant volume of blood can collect in the mediastinum over time and drain through
the chest tubes when the patient is turned. If the blood is dark rather than bright red and
there is normal additional drainage after the patient is repositioned, it has most likely
been accumulating over time and does not necessarily indicate active significant
bleeding. Bright red blood that continues to drain in excessive amounts, and changes in
the patients BP and hemodynamics would indicate ongoing bleeding and needs to be
reported immediately. General guidelines for return to the OR for bleeding include: >
400 ml/hour for 1 hour, > 300 ml/hour for 2-3 hours, > 200 ml/hour for 4 hours. A fluid
bolus would be appropriate if bleeding continues and the patient is hypotensive with low
filling pressures (CVP, PWP).
✔✔Which of the following is an indication for emergency chest reopening in the ICU in a
post cardiac surgery patient:
A. Hypotension, CVP < 3 mmHg, PWP or PA diastolic < 15 mmHg.
B. Cardiac tamponade with imminent cardiac arrest or exsanguinating hemorrhage.
C. Chest tube drainage > 300 ml/hour.
D. All of the above. - ✔✔B. Exsanguinating hemorrhage and cardiac tamponade with
imminent cardiac arrest are indications for emergency reopening of the chest in the ICU.
Cardiac tamponade is fatal if pressure around the heart is not relieved. Reopening the
sternal incision may be enough to relieve pressure around the heart and allows
identification of bleeding sites that can be controlled with pressure or suturing. Internal
defibrillation can be done using internal defibrillation paddles placed directly on the
heart if VF is present, and internal cardiac massage can be done if necessary.
Chest tube drainage > 300 ml/hour for 2-3 hours indicates excessive bleeding and
warrants a return trip to the OR but not reopening in the ICU unless cardiac arrest
occurs.
Hypotension with a low CVP and PA diastolic or PWP indicates hypovolemia and can
be treated with fluids and/or blood product administration but does not require
reopening of the chest.
✔✔Which of the following post-op CABG patients is NOT ready to be weaned from
mechanical ventilation despite adequate ABGs:
A. Patient requiring 10 cm H2O PEEP and FIO2 of 50% to maintain adequate PO2.
B. Patient receiving dexmedetomidine.
C. Patient with cardiac index of 2.4 L/min/m2, HR 100, chest tube drainage 30 ml/hr.
AND ANSWERS SURE A+
✔✔Your postoperative CABG patient has atrial fibrillation with a ventricular rate in the
40's. Atrial and ventricular epicardial pacing wires are in place. Which pacing mode is
indicated to increase the heart rate in this patient:
A. DDD.
B. VVI.
C. DVI.
D. AAI. - ✔✔B. Atrial fibrillation with a slow ventricular response requires VVI pacing to
maintain an adequate ventricular rate. Atrial pacing and sensing are ineffective in atrial
fibrillation, therefore any mode that utilizes atrial pacing or atrial sensing is not indicated.
The AAI, DVI, and DDD modes all utilize atrial pacing or sensing and are not indicated
for this patient.
✔✔Inotropic support is often needed for the first few hours following CABG surgery
when there is left ventricular dysfunction present. Which of the following drugs are
appropriate for inotropic support:
A. Nitroglycerine or nitroprusside.
B. Norepinephrine or vasopressin.
C. Milrinone, dobutamine, dopamine, or epinephrine.
D. Esmolol, metoprolol, or nicardipine. - ✔✔C. Milrinone, dobutamine, dopamine, and
epinephrine all increase contractility. Milrinone is also a vasodilator so would be
indicated when inotropic support is needed in the presence of a high SVR. Dobutamine,
dopamine, and epinephrine all have beta adrenergic effects to increase contractility.
Epinephrine is often the preferred inotropic agent because it causes less tachycardia
than dopamine or dobutamine and also has some peripheral vasoconstrictor effects that
can help support the blood pressure.
Nitroglycerin and nitroprusside are both vasodilators with no inotropic effect.
Nitroglycerin is primarily a venous dilator and is used for preload reduction.
Nitroprusside has both venous and arterial vasodilating effects with somewhat more
arterial effect and is used to manage postoperative hypertension.
Esmolol and metoprolol are beta blockers and nicardipine is a calcium channel blocker.
Beta blockers and calcium channel blockers are negative inotropic drugs and decrease
,contractility. Nicardipine is also a peripheral vasodilator and can be used to treat
postoperative hypertension.
✔✔Myocardial stunning can be a cause of postoperative left ventricular dysfunction.
Which of the following best describes stunning:
A. Normal ventricular function in the presence of excessively high afterload.
B. Intraoperative ischemia resulting in permanent left ventricular dysfunction.
C. Transient ischemia followed by myocardial reperfusion and normal left ventricular
function.
D. Transient ischemia followed by myocardial reperfusion and left ventricular
dysfunction of limited duration. - ✔✔D. Myocardial stunning is transient post ischemic
LV dysfunction that occurs after total or significant reduction of coronary blood flow,
followed by reestablishment of coronary flow. The LV dysfunction is of limited duration
and improves over time with support from inotropic agents or mechanical assist (i.e.
IABP). In the cardiac surgery patient, stunning can occur when coronary flow is
disrupted by CPB and then reestablished at the end of the procedure and is one of the
causes of postoperative low cardiac output syndrome.
✔✔Which of the following is true concerning the use of aspirin following CABG surgery:
A. ASA is contraindicated because of the increased risk of bleeding from new grafts.
B. ASA is indicated for all CABG patients because of its antiplatelet effects and for
secondary prevention of coronary disease.
C. ASA is indicated for patients receiving arterial grafts but not venous grafts.
D. ASA is indicated for all CABG patients as an analgesic for postoperative pain control.
- ✔✔C. The use of ASA in the early postoperative period is used to offset platelet
activation and aggregation in the early postop period. ASA may result in improved graft
patency; decrease the incidence of perioperative MI, stroke, and acute kidney injury;
and reduce mortality. It is recommended that ASA be started within 6 hours
postoperatively (after mediastinal bleeding has stopped) and continued indefinitely for
secondary prevention in all CABG patients who do not have a contraindication to ASA.
✔✔Atrial fibrillation is particularly dangerous in which of these patients:
A. Patient with mitral valve replacement for mitral stenosis.
B. Patient who had 5-vessel CABG.
C. Patient with aortic valve replacement for aortic stenosis.
D. Patient with preoperative LV dysfunction. - ✔✔C. Aortic stenosis causes left
ventricular hypertrophy with a stiff noncompliant LV and diastolic failure. A noncompliant
LV depends on atrial kick for adequate preload and stroke volume. Sinus rhythm or AV
pacing is especially important in this patient to maintain AV synchrony and adequate
preload. Atrial fibrillation results in a loss of atrial kick and can lead to profound
hemodynamic deterioration.
Atrial fibrillation can occur in any post operative cardiac surgery patient and is especially
common in mitral valve disease because of the increased atrial pressure and/or volume
that occurs. However, it is better tolerated in patients who do not have LV diastolic
dysfunction or LV hypertrophy.
,✔✔Your patient has had an aortic valve replacement for severe aortic stenosis. She has
been in sinus rhythm at a rate of 70 with adequate hemodynamics but has now gone in
to 3rd degree AV block with a junctional rhythm at a rate of 40 beats per minute and is
hypotensive. Atrial and ventricular epicardial pacing wires are present. What type of
pacing would be best in this patient:
A. DDD.
B. DVI.
C. AAI.
D. VVI. - ✔✔A.A patient with aortic stenosis has a stiff noncompliant LV that depends
on atrial kick for much of its preload to maintain an adequate stroke volume. DDD
pacing means that the pacemaker paces atria and ventricles (first D), senses in atria
and ventricles (second D), and inhibits or triggers pacing depending on whether atrial or
ventricular activity was sensed (third D). The DDD pacing mode allows the pacemaker
to sense the patient's own P waves and paces the ventricle in response to those P
waves, thus maintaining AV synchrony and improving LV preload. The DDD pacing
mode always maintains AV synchrony regardless of what the underlying rhythm is.
This patient is in third degree block, so pacing the atrium alone (AAI) will do no good
since there is no AV conduction present.
VVI pacing would increase the ventricular rate but would not maintain AV synchrony.
DVI pacing paces both the atria and the ventricles but only senses in the ventricle,
therefore it would not sense her intrinsic P waves but would pace both atria and
ventricles at the minimum rate set in the pacemaker. Since this patient has an adequate
sinus rhythm, the DDD mode is better because it will allow for atrial sensing and pace
the ventricle in response to her intrinsic P waves. Both DDD and DVI modes preserve
AV synchrony.
✔✔Antifibrinolytic drugs used to reduce intraoperative or postoperative blood loss
include:
A. Amicar (aminocaproic acid) and cyclokapron (tranexaminic acid).
B. Aprotinin and amicar.
C. tPA (tissue plasminogen activator) and clopidogrel.
D. Protamine and vitamin K. - ✔✔A. Amicar and cyclokapron are antifibrinolytic drugs
that inhibit the breakdown of fibrin. They are used in both on- and off-pump cases to
reduce intraoperative bleeding and can be used in postoperative patients who are
bleeding excessively. Aprotinin is another antifibrinolytic drug that was commonly used
to reduce blood loss but it is no longer being manufactured because of the risk of renal
dysfunction and increased mortality.
Tissue plasminogen activator (tPA) is a thrombolytic drug used to break down clots in
acute coronary syndromes and acute ischemic stroke. Bleeding is a common side effect
of tPA and it is not indicated in cardiac surgery patients.
Clopidogrel is a P2Y12 receptor inhibitor that inhibits platelet activation and is used in
acute coronary syndromes and ischemic stroke. Bleeding is a side effect of P2Y12
inhibitors and they are not used in patients who are bleeding.
Protamine is used to reverse heparin at the end of a cardiac surgical procedure and
therefore is used to reduce the incidence of bleeding, but it is not an antifibrinolytic
, agent. Vitamin K is used to reverse the effects of warfarin and is not an antifibrinolytic
agent.
✔✔When you turn your post CABG patient you notice about 100 ml of dark blood
dumping through the chest tubes. You should now do which of the following:
A. Ignore it because it is normal for dumping to occur with position changes.
B. Immediately notify the surgeon because this indicates acute and excessive bleeding
that could require surgical intervention.
C. Evaluate blood pressure and hemodynamic values and give a 500 cc fluid bolus.
D. Assess blood pressure and hemodynamic values to evaluate patient's condition and
observe chest tubes for additional drainage once patient is repositioned. - ✔✔D. A
significant volume of blood can collect in the mediastinum over time and drain through
the chest tubes when the patient is turned. If the blood is dark rather than bright red and
there is normal additional drainage after the patient is repositioned, it has most likely
been accumulating over time and does not necessarily indicate active significant
bleeding. Bright red blood that continues to drain in excessive amounts, and changes in
the patients BP and hemodynamics would indicate ongoing bleeding and needs to be
reported immediately. General guidelines for return to the OR for bleeding include: >
400 ml/hour for 1 hour, > 300 ml/hour for 2-3 hours, > 200 ml/hour for 4 hours. A fluid
bolus would be appropriate if bleeding continues and the patient is hypotensive with low
filling pressures (CVP, PWP).
✔✔Which of the following is an indication for emergency chest reopening in the ICU in a
post cardiac surgery patient:
A. Hypotension, CVP < 3 mmHg, PWP or PA diastolic < 15 mmHg.
B. Cardiac tamponade with imminent cardiac arrest or exsanguinating hemorrhage.
C. Chest tube drainage > 300 ml/hour.
D. All of the above. - ✔✔B. Exsanguinating hemorrhage and cardiac tamponade with
imminent cardiac arrest are indications for emergency reopening of the chest in the ICU.
Cardiac tamponade is fatal if pressure around the heart is not relieved. Reopening the
sternal incision may be enough to relieve pressure around the heart and allows
identification of bleeding sites that can be controlled with pressure or suturing. Internal
defibrillation can be done using internal defibrillation paddles placed directly on the
heart if VF is present, and internal cardiac massage can be done if necessary.
Chest tube drainage > 300 ml/hour for 2-3 hours indicates excessive bleeding and
warrants a return trip to the OR but not reopening in the ICU unless cardiac arrest
occurs.
Hypotension with a low CVP and PA diastolic or PWP indicates hypovolemia and can
be treated with fluids and/or blood product administration but does not require
reopening of the chest.
✔✔Which of the following post-op CABG patients is NOT ready to be weaned from
mechanical ventilation despite adequate ABGs:
A. Patient requiring 10 cm H2O PEEP and FIO2 of 50% to maintain adequate PO2.
B. Patient receiving dexmedetomidine.
C. Patient with cardiac index of 2.4 L/min/m2, HR 100, chest tube drainage 30 ml/hr.
