CARDIAC SURGERY CSC EVALUATION EXAMS
QUESTIONS AND ANSWERS SURE A+
✔✔Post-operative wound infection is a serious complication resulting in increased post-
operative mortality. Patient characteristics that place the patient at high risk for the
development of post-operative wound infections include all of the following EXCEPT:
A. Diabetes.
B. Obesity.
C. Race.
D. Excessive use of electrocautery.
E. End stage renal disease. - ✔✔C. Risk factors for the development of infection
include: obesity, diabetes, end stage renal disease, re-operation, excessive use of
electrocautery, prolonged mechanical ventilation, and use of both internal mammary
arteries (decreased blood flow to the sternum).
✔✔Your post-op CABG/ AVR patient develops 2nd degree type II AV block with an
associated drop in systolic blood pressure. The patient has atrial and ventricular
epicardial pacing wires. The best pacing mode in this situation would be:
A. AAI.
B. DVI.
C. DDD.
D. VVI. - ✔✔C. DDD pacing mode is the best option because it maintains AV
synchrony. This mode allows for tracking of atrial activity when it is present and paces
the ventricle after every sensed P wave. It also paces the atrium when the sinus rate is
too low.
AAI is an atrial pacing mode and requires intact AV conduction. This patient is
experiencing an AV conduction disturbance, so pacing the atrium will do no good.
While a VVI mode would provide an adequate ventricular rate, this is not the best option
since you have both atrial and ventricular wires. If you have the ability to provide AV
synchrony, as you do with DDD pacing, then you should do this when there is an AV
conduction abnormality.
DVI mode only senses in the ventricle, therefore it would not sense atrial activity and
maintain AV synchrony in the presence of AV block.
,✔✔During the immediate postoperative period, the goal glucose level in the diabetic
patient with an anticipated ICU LOS of less 48 hours is:
A. < 250 mg/dl.
B. Glucose control is not important in the post operative cardiac surgery patient.
C. <120 mg/dl.
D. < 180 mg/dl. - ✔✔D. Due to potential hypoglycemic complications involved in therapy
to maintain strict glycemic control, recent guidelines for glucose control in the patient
undergoing CABG include the following parameters:
Preoperative: HgbA1c assessed preoperatively in diabetics.
Intraoperative: insulin infusion for diabetics intraoperatively, SQ insulin acceptable for
non diabetics as long as glucose < 180 mg/dl.
Postoperative: IV insulin drip for 24 hours in diabetics, SQ insulin acceptable for non-
diabetics.
Complex patients (ICU greater than 3 days) maintain glucose < 150 mg/dl.
✔✔The AAI pacing mode would most likely be used in a postoperative cardiac surgery
patient with which of the following situations resulting in hemodynamic compromise:
A. 2nd degree type II heart block.
B. Ventricular tachycardia.
C. Sinus bradycardia.
D. Complete heart block. - ✔✔C. The AAI pacing mode is only utilized when there is
intact AV conduction. In sinus bradycardia, the problem is the slow sinus rate - not AV
block, so pacing the atrium would fix the problem. AAI mode is used most frequently in
the post-operative cardiac patient to increase heart rate to enhance cardiac output when
the risk of AV block is small.
Whenever AV block is present, either DDD or VVI pacing can be used to assure an
adequate ventricular rate - the advantage of DDD mode would be maintenance of AV
synchrony.
Antitachycardia pacing as part of an ICD could terminate VT, but Acai pacing would
have no effect on VT.
✔✔You are caring for a patient who returned from CABG surgery 4 hours ago. You
expect drainage from the mediastinal chest tubes to:
A. Be at least 200 ml/hr for the first 2 hours.
B. Drainage should have stopped by now.
C. Be bright red with clots present.
D. Be <100 ml per hour. - ✔✔D. Drainage from chest tubes should be no more than 100
ml/hr on return from surgery and should gradually decrease over the first 3-4 hours.
Bright red blood and clots or drainage >200 ml/hr can indicate surgical bleeding and
should be reported. The patient will probably need to return to surgery if drainage is >
400 ml/hr, or > 300 ml/hr for 2-3 hours, or >200ml/hr for 4 hours. A sudden decrease in
drainage can indicate the presence of clots obstructing chest tubes or can be a sign of
tamponade. Chest tubes are usually removed in about 24 hours if drainage is <20 ml/hr
,✔✔The use of cardiopulmonary bypass (CPB) during cardiac surgery is associated with
which of the following effects:
A. Increased vascular permeability and increased intravascular coagulation.
B. Increased intravascular coagulation and hypovolemia.
C. Hyperthermia and increased vascular permeability.
D. Increased inflammatory response and hemodilution. - ✔✔D. Prior to initiating CPB,
the pump and its tubing are primed with about 1500 ml of fluid which causes
hemodilution. Hemodilution is associated with a decrease in Hgb, Hct, platelets, clotting
factors, serum albumin, and electrolytes. This can result in dilutional thrombocytopenia
and coagulopathy that increases the risk of bleeding. Heparin is used during CPB to
prevent clotting in the circuit, and this can contribute to bleeding. CPB also initiates a
systemic inflammatory response as blood comes in contact with the foreign material in
the bypass circuitry. This inflammatory response triggers the release of several
substances that impair coagulation and the immune response, and cause increased
vascular permeability leading to fluid shifts from the intravascular space to the interstitial
space.
Hypothermia is induced to protect the heart and reduce metabolic demands while the
patient is on CPB. Hypothermia results in vasoconstriction which increases afterload,
shivering which increases metabolic demand, and increases the risk of bleeding,
arrhythmias, and organ dysfunction post operatively.
✔✔Your patient arrived 2 hours ago from the OR following CABG surgery. His chest
tube drainage was 200 ml the first hour, but has stopped now. His BP was 136/76 and
when you check it now you get 110/60 during expiration and 88/54 during inspiration.
His CVP is 17, PWP is 18, PA pressure is 32/18, neck veins are elevated. You suspect
which of the following:
A. Normal postoperative course.
B. Low cardiac output syndrome due to perioperative MI.
C. Cardiac tamponade.
D. Hypovolemia due to bleeding from his grafts. - ✔✔C.Cardiac tamponade is a life-
threatening emergency that can occur immediately or within the first several hours after
cardiac surgery. Tamponade occurs when blood or clot accumulates in the mediastinum
and compresses the right heart. When the right heart is compressed the RV cannot
adequately fill the left ventricle, so LV filling pressure is low, resulting in low cardiac
output and hemodynamic instability. Signs and symptoms of cardiac tamponade
include: 1) JVD and increased CVP reflecting elevated right heart pressure, 2) pulsus
paradoxus (>10 mmHg drop in systolic BP during inspiration) that occurs when blood
enters the compressed RV during inspiration and causes the septum to bulge into the
LV, reducing LV filing and decreasing stroke volume further during inspiration; 3)
hypotension due to decreased LV stroke volume, 4) equalization of CVP, PWP, and PA
diastolic pressures, 5) sudden or significant decrease in chest tube drainage. Other
signs may include decreased QRS voltage on the ECG, muffled heart sounds, widened
mediastinum on chest X-ray, and tachycardia (although cardiac surgery patients
receiving beta blockers or calcium channel blockers may not be able to mount a
compensatory tachycardia). Beck's Triad is often associated with the clinical
assessment findings of cardiac tamponade: hypotension, muffled heart sounds, and
, JVD. This patient's CVP is 17 and his PWP and PAD are both 18 indicating equalization
of pressures.
Hypovolemia due to bleeding from grafts can cause hypotension but would not cause
JVD or pulsus paradoxus, and filling pressures (CVP and PWP) would be low.
Perioperative MI can cause hypotension due to LV dysfunction but would not be
associated with pulsus paradoxus or equalization of intracardiac pressures, and would
not cause a sudden decrease in chest drainage.
✔✔A patient with epicardial atrial and ventricular pacing wires post cardiac surgery has
a change in his rhythm on the bedside monitor. Which of the following connections
would allow you to obtain an atrial electrogram to help diagnose the rhythm:
A. Connect a ventricular pacing wire to the chest lead and record 'V' on the bedside
monitor.
B. Connect an atrial pacing wire to the right leg electrode and record "V" on the bedside
monitor
C. Connect an atrial pacing wire to the chest lead on your monitor cable and record lead
II on the bedside monitor.
D. Connect an atrial pacing wire to the chest lead on your monitor cable and record 'V'
on the bedside monitor. - ✔✔D.Recording an atrial electrogram directly from an atrial
pacing wire allows easy identification of atrial activity (P waves or flutter/fib waves) and
helps illustrate the relationship between P waves and QRS complexes when it is difficult
to see on a surface lead. The easiest way to do this is to attach a monitoring electrode
to the chest lead on a 5-wire monitor cable and wrap it tightly around the metal end of
an atrial pacing wire, making sure that the metal end of the pacing wire is in the gel
center of the electrode and touching the metal portion of the button under the gel. Then
set the monitor to record 'V', which records from the chest lead that is now attached to
the atrial pacing wire. This connection will provide a unipolar recording (using one atrial
wire) with very large atrial deflections. The connection between the atrial pacing wire
and the monitor lead can also be made using an alligator clip, but this method using a
regular monitoring electrode doesn't require any special equipment. It is a good idea to
simultaneously record a surface lead along with the atrial electrogram and to run the
paper at double speed through the recorder to spread the tracing out for better
visualization.
Lead II on the monitor is recorded between the right arm and the left leg electrodes, not
the chest lead.
Connecting a ventricular pacing lead will only accentuate the QRS, not the P waves.
This illustration shows the connection of the chest lead on the monitor to an atrial
pacing wire using a regular monitoring electrode.
✔✔A patient with epicardial atrial and ventricular pacing wires post cardiac surgery
displays the rhythm seen in the lead II strip (top strip) on the bedside monitor. The nurse
on the previous shift documented the rhythm as junctional rhythm because no P waves
were seen in Lead II on the monitor. You decide to obtain an atrial electrogram and
record the bottom strip (labeled AEG). .(P WAVES BEFORE EVERY QRS) You
document the rhythm as:
A. Normal sinus rhythm.
QUESTIONS AND ANSWERS SURE A+
✔✔Post-operative wound infection is a serious complication resulting in increased post-
operative mortality. Patient characteristics that place the patient at high risk for the
development of post-operative wound infections include all of the following EXCEPT:
A. Diabetes.
B. Obesity.
C. Race.
D. Excessive use of electrocautery.
E. End stage renal disease. - ✔✔C. Risk factors for the development of infection
include: obesity, diabetes, end stage renal disease, re-operation, excessive use of
electrocautery, prolonged mechanical ventilation, and use of both internal mammary
arteries (decreased blood flow to the sternum).
✔✔Your post-op CABG/ AVR patient develops 2nd degree type II AV block with an
associated drop in systolic blood pressure. The patient has atrial and ventricular
epicardial pacing wires. The best pacing mode in this situation would be:
A. AAI.
B. DVI.
C. DDD.
D. VVI. - ✔✔C. DDD pacing mode is the best option because it maintains AV
synchrony. This mode allows for tracking of atrial activity when it is present and paces
the ventricle after every sensed P wave. It also paces the atrium when the sinus rate is
too low.
AAI is an atrial pacing mode and requires intact AV conduction. This patient is
experiencing an AV conduction disturbance, so pacing the atrium will do no good.
While a VVI mode would provide an adequate ventricular rate, this is not the best option
since you have both atrial and ventricular wires. If you have the ability to provide AV
synchrony, as you do with DDD pacing, then you should do this when there is an AV
conduction abnormality.
DVI mode only senses in the ventricle, therefore it would not sense atrial activity and
maintain AV synchrony in the presence of AV block.
,✔✔During the immediate postoperative period, the goal glucose level in the diabetic
patient with an anticipated ICU LOS of less 48 hours is:
A. < 250 mg/dl.
B. Glucose control is not important in the post operative cardiac surgery patient.
C. <120 mg/dl.
D. < 180 mg/dl. - ✔✔D. Due to potential hypoglycemic complications involved in therapy
to maintain strict glycemic control, recent guidelines for glucose control in the patient
undergoing CABG include the following parameters:
Preoperative: HgbA1c assessed preoperatively in diabetics.
Intraoperative: insulin infusion for diabetics intraoperatively, SQ insulin acceptable for
non diabetics as long as glucose < 180 mg/dl.
Postoperative: IV insulin drip for 24 hours in diabetics, SQ insulin acceptable for non-
diabetics.
Complex patients (ICU greater than 3 days) maintain glucose < 150 mg/dl.
✔✔The AAI pacing mode would most likely be used in a postoperative cardiac surgery
patient with which of the following situations resulting in hemodynamic compromise:
A. 2nd degree type II heart block.
B. Ventricular tachycardia.
C. Sinus bradycardia.
D. Complete heart block. - ✔✔C. The AAI pacing mode is only utilized when there is
intact AV conduction. In sinus bradycardia, the problem is the slow sinus rate - not AV
block, so pacing the atrium would fix the problem. AAI mode is used most frequently in
the post-operative cardiac patient to increase heart rate to enhance cardiac output when
the risk of AV block is small.
Whenever AV block is present, either DDD or VVI pacing can be used to assure an
adequate ventricular rate - the advantage of DDD mode would be maintenance of AV
synchrony.
Antitachycardia pacing as part of an ICD could terminate VT, but Acai pacing would
have no effect on VT.
✔✔You are caring for a patient who returned from CABG surgery 4 hours ago. You
expect drainage from the mediastinal chest tubes to:
A. Be at least 200 ml/hr for the first 2 hours.
B. Drainage should have stopped by now.
C. Be bright red with clots present.
D. Be <100 ml per hour. - ✔✔D. Drainage from chest tubes should be no more than 100
ml/hr on return from surgery and should gradually decrease over the first 3-4 hours.
Bright red blood and clots or drainage >200 ml/hr can indicate surgical bleeding and
should be reported. The patient will probably need to return to surgery if drainage is >
400 ml/hr, or > 300 ml/hr for 2-3 hours, or >200ml/hr for 4 hours. A sudden decrease in
drainage can indicate the presence of clots obstructing chest tubes or can be a sign of
tamponade. Chest tubes are usually removed in about 24 hours if drainage is <20 ml/hr
,✔✔The use of cardiopulmonary bypass (CPB) during cardiac surgery is associated with
which of the following effects:
A. Increased vascular permeability and increased intravascular coagulation.
B. Increased intravascular coagulation and hypovolemia.
C. Hyperthermia and increased vascular permeability.
D. Increased inflammatory response and hemodilution. - ✔✔D. Prior to initiating CPB,
the pump and its tubing are primed with about 1500 ml of fluid which causes
hemodilution. Hemodilution is associated with a decrease in Hgb, Hct, platelets, clotting
factors, serum albumin, and electrolytes. This can result in dilutional thrombocytopenia
and coagulopathy that increases the risk of bleeding. Heparin is used during CPB to
prevent clotting in the circuit, and this can contribute to bleeding. CPB also initiates a
systemic inflammatory response as blood comes in contact with the foreign material in
the bypass circuitry. This inflammatory response triggers the release of several
substances that impair coagulation and the immune response, and cause increased
vascular permeability leading to fluid shifts from the intravascular space to the interstitial
space.
Hypothermia is induced to protect the heart and reduce metabolic demands while the
patient is on CPB. Hypothermia results in vasoconstriction which increases afterload,
shivering which increases metabolic demand, and increases the risk of bleeding,
arrhythmias, and organ dysfunction post operatively.
✔✔Your patient arrived 2 hours ago from the OR following CABG surgery. His chest
tube drainage was 200 ml the first hour, but has stopped now. His BP was 136/76 and
when you check it now you get 110/60 during expiration and 88/54 during inspiration.
His CVP is 17, PWP is 18, PA pressure is 32/18, neck veins are elevated. You suspect
which of the following:
A. Normal postoperative course.
B. Low cardiac output syndrome due to perioperative MI.
C. Cardiac tamponade.
D. Hypovolemia due to bleeding from his grafts. - ✔✔C.Cardiac tamponade is a life-
threatening emergency that can occur immediately or within the first several hours after
cardiac surgery. Tamponade occurs when blood or clot accumulates in the mediastinum
and compresses the right heart. When the right heart is compressed the RV cannot
adequately fill the left ventricle, so LV filling pressure is low, resulting in low cardiac
output and hemodynamic instability. Signs and symptoms of cardiac tamponade
include: 1) JVD and increased CVP reflecting elevated right heart pressure, 2) pulsus
paradoxus (>10 mmHg drop in systolic BP during inspiration) that occurs when blood
enters the compressed RV during inspiration and causes the septum to bulge into the
LV, reducing LV filing and decreasing stroke volume further during inspiration; 3)
hypotension due to decreased LV stroke volume, 4) equalization of CVP, PWP, and PA
diastolic pressures, 5) sudden or significant decrease in chest tube drainage. Other
signs may include decreased QRS voltage on the ECG, muffled heart sounds, widened
mediastinum on chest X-ray, and tachycardia (although cardiac surgery patients
receiving beta blockers or calcium channel blockers may not be able to mount a
compensatory tachycardia). Beck's Triad is often associated with the clinical
assessment findings of cardiac tamponade: hypotension, muffled heart sounds, and
, JVD. This patient's CVP is 17 and his PWP and PAD are both 18 indicating equalization
of pressures.
Hypovolemia due to bleeding from grafts can cause hypotension but would not cause
JVD or pulsus paradoxus, and filling pressures (CVP and PWP) would be low.
Perioperative MI can cause hypotension due to LV dysfunction but would not be
associated with pulsus paradoxus or equalization of intracardiac pressures, and would
not cause a sudden decrease in chest drainage.
✔✔A patient with epicardial atrial and ventricular pacing wires post cardiac surgery has
a change in his rhythm on the bedside monitor. Which of the following connections
would allow you to obtain an atrial electrogram to help diagnose the rhythm:
A. Connect a ventricular pacing wire to the chest lead and record 'V' on the bedside
monitor.
B. Connect an atrial pacing wire to the right leg electrode and record "V" on the bedside
monitor
C. Connect an atrial pacing wire to the chest lead on your monitor cable and record lead
II on the bedside monitor.
D. Connect an atrial pacing wire to the chest lead on your monitor cable and record 'V'
on the bedside monitor. - ✔✔D.Recording an atrial electrogram directly from an atrial
pacing wire allows easy identification of atrial activity (P waves or flutter/fib waves) and
helps illustrate the relationship between P waves and QRS complexes when it is difficult
to see on a surface lead. The easiest way to do this is to attach a monitoring electrode
to the chest lead on a 5-wire monitor cable and wrap it tightly around the metal end of
an atrial pacing wire, making sure that the metal end of the pacing wire is in the gel
center of the electrode and touching the metal portion of the button under the gel. Then
set the monitor to record 'V', which records from the chest lead that is now attached to
the atrial pacing wire. This connection will provide a unipolar recording (using one atrial
wire) with very large atrial deflections. The connection between the atrial pacing wire
and the monitor lead can also be made using an alligator clip, but this method using a
regular monitoring electrode doesn't require any special equipment. It is a good idea to
simultaneously record a surface lead along with the atrial electrogram and to run the
paper at double speed through the recorder to spread the tracing out for better
visualization.
Lead II on the monitor is recorded between the right arm and the left leg electrodes, not
the chest lead.
Connecting a ventricular pacing lead will only accentuate the QRS, not the P waves.
This illustration shows the connection of the chest lead on the monitor to an atrial
pacing wire using a regular monitoring electrode.
✔✔A patient with epicardial atrial and ventricular pacing wires post cardiac surgery
displays the rhythm seen in the lead II strip (top strip) on the bedside monitor. The nurse
on the previous shift documented the rhythm as junctional rhythm because no P waves
were seen in Lead II on the monitor. You decide to obtain an atrial electrogram and
record the bottom strip (labeled AEG). .(P WAVES BEFORE EVERY QRS) You
document the rhythm as:
A. Normal sinus rhythm.
