This document provides information on post-cardiac surgery monitoring and follow up. It discusses admission to the ICU, initial assessment, monitoring techniques, complications that can occur like bleeding and hemodynamic issues, and management strategies for those complications. The early focus is on stabilizing vital signs, addressing hypothermia, identifying potential issues like low cardiac output, and treating medical causes of bleeding through correcting coagulation abnormalities.

1. Post Cardiac surgery
Monitoring & Follow up
Presented by
Dr. Kazi Md Rubayet Anwar MD, MRCP,FCPS, MBBS
National institute of cardiovascular diseases
NICVD, Dhaka.

2. Introduction
The most common surgical procedure encountered is the Aorto-Coronary
Bypass Graft (ACBG) for various indications such as left main coronary
artery stenosis, severe triple-vessel disease, angina refractory to medical
therapy, or recurrent CHF due to ischemia.
Other surgical procedures, concomitantly with ACBG or alone, include valve
repair or replacements, repair of congenital or acquired defects (ASD, VSD,
etc.), and repair or replacement of the aortic root. Less common are removal
of intracardiac tumors and LV aneurysmectomy.

3. Introduction
It goes without saying that prevention of complications requires a thorough
understanding of the pathophysiologic basis for the development of organ
dysfunction after cardiac surgery, the ability to identify high-risk patients,
and the ability to execute therapeutic strategies that prevent complications
from developing.
In many of those patients who develop complications, early diagnosis and
treatment prevent further deterioration and limit subsequent morbidity and
mortality.

4. Introduction
The early management of the postoperative open heart surgery patient can be
viewed as an extension of the intraoperative care the patient received, with a
focus on recovery from hypothermia, restoring hemostatic capability,
recognition and support during the inflammatory condition provoked by
cardiopulmonary bypass (CPB) itself, and optimization of cardiac function
as the heart recovers from the transient ischemic injury.

5. Spectrum of CPB
To perform the surgery, the patient is usually put on "pump" or
cardiopulmonary bypass (CPB). This involves cannulation of the right atrium
and aorta (and later cross-clamping of the aorta), allowing the entire cardiac
output to bypass the patient's heart and lungs. Blood flow is maintained using
a pump and the blood is oxygenated via a membrane oxygenator incorporated
into the circuit. Several myocardial preservation techniques are used to
protect the heart from ischemic damage during this period. Cardioplegic
arrest is induced using a hyperkalemic solution to induce asystole and thus
decrease myocardial metabolism and oxygen consumption. The heart is
usually cooled. The patient is also usually systemically cooled to < 32 C to
minimize peripheral oxygen consumption.

6. Spectrum of CPB
While "on pump", the patient's BP and cardiac output are controlled by by
the perfusionist and also the anesthesiologist by means of vasoactive
medications and inotropes. During this time, the patient must by systemically
anticoagulated with heparin to an ACT >400 to prevent clotting in the
bypass circuit. complications such as bleeding, myocardial stunning, and
multi-system organ failure. CPB also seems to be associated with the
induction of a systemic inflammatory response syndrome (SIRS). A variety
of dysrhythmias also may occur during this period including bradycardias
requiring pacing. Most often, these dysrhythmias are transient and resolve.

7. Spectrum of CPB
In the past few years, more cases are being done with "beating heart" or "off
pump". The advantages of Off-pump Coronary Artery Bypass (OPCAB) are
that the patient is not exposed to the possible deleterious effects of CPB.
In some operations involving the aortic root, cross-clamping and cannulation
of the aorta are not feasible. In these situations the technique of Deep
Hypothermic Circulatory Arrest (DHCA) may be used. The patient is
systemically cooled as much as possible (usually below 28 C) and a large dose
of barbiturates are given as a neuroprotective agent. The circulation is then
completely arrested for a brief period of time to allow completion of the
surgical anastomosis.

8. Complication of cardiac surgery
 Decrease Cardiac Output
I. Hypovolaemia
II. Bleeding
III. Cardiac tamponade
IV. Fluid overload
V. Hypothermia
VI. Hypertension
VII. Tachydysrhythmias
VIII. Bradycardia
IX. Cardiac failure
X. Myocardial infarction
 Pulmonary complications
 Neurologic change and stroke
 Renal failure and E. imbalance
 Acute Renal Failure
 Others

9. Immediate post-op care
The resident should be present in the ICU when the patient arrives from
the operating room to receive a sign-over from the anesthesiologist and
the cardiac surgical team.
During this period, the ICU nurses will be transferring the patient to the
ICU monitors and checking all lines and infusions. The nurse will then
do the initial set of hemodynamic readings.
The Respiratory Technician will place the patient on a ventilator. Unless
the patient is unstable it is best to stay out of the way of the nurses
during this period.

10. Admission to the ICU and
Monitoring Techniques

11. Admission to the ICU
A. The first critical phase of post operative care
This is the transition from one set up to another. Troubleshooting areas are: airway and
ventilation problems, sudden hypotension or hypertension, arrhythmias, inadvertent medication
changes, and unidentified problems with invasive catheters, monitoring, and bleeding.
N.B:
1. The electrocardiogram (ECG) and pressure tracings (arterial, central venous, and/or
pulmonary artery) are transferred one at a time from the operating room monitor to the
transport module
2. Ventilation is provided by an Ambu bag connected to a portable oxygen tank.
3. Drug infusions should be placed on battery-powered infusion pumps to ensure accurate
infusion rates.
A selection of cardiac medications should always be available in the event of an emergency
during transport.

12. Admission to the ICU
B. Upon arrival in the ICU
• The endotracheal tube is connected to a mechanical ventilator,
• ECG and pressure lines are transduced on a bedside monitor.
• A pulse oximeter is attached to one of the patient’s fingertips.
• Medication drip rates are confirmed or readjusted on controlled infusion
pumps, preferably using the same pumps.
• The thoracic drainage system is connected to suction.

13. During this transition phase, much attention is directed to getting the patient connected
to the monitors and attached to the ventilator.
It is critical that the patient should be accompanied with anesthesia and/or surgical personnel
as well as the accepting nurses and respiratory therapists.
Make sure that:
1. The patient is being well-ventilated by observing chest movement and auscultating
bilateral breath sounds.
2. The ECG tracing demonstrates satisfactory rate and rhythm on the transport and
then the bedside monitor.
3. The blood pressure is adequate on the portable monitor and remains so
after the arterial line is transduced and calibrated on the bedside monitor.
Admission to the ICU

14. History and assessment
Immediate assessment and response to any abnormalities suspected to be present at the time of admission to
the ICU, whether real or spurious, is imperative.
Collect the following information from the anesthesiologist, surgeon, and the patient chart.
• Patient background (age, sex)
• Type of operation (CABG, valve, elective vs. urgent etc)
• Indications for operation
• Pre-operative cath report (vessels involved, LVEF)
• Success of operation (completely or incompletely revascularized, difficulties, complications)
• CPB time and aortic cross-clamp time

15. • Ease of separation from CPB ( dysrhythmias, need for inotropes, pacing, etc).
• Difficulty coming off pump may imply problems with myocardial preservation
or with the revascularization.
• Current inotropes, vasopressors, or anti-hypertensives (if any)
• Need for cardiac pacing
• Use of Intra-aortic balloon pump (IABP), ventricular assist devices (VAD), or
nitric oxide (NO).
• Significant bleeding
• Other
significant co morbidity, with emphasis on those conditions that may alter the
post-operative management or course (carotid artery disease, COPD, asthma,
diabetes, renal failure, hepatic failure, etc.)
Pre-operative medications
Allergies

16. Physical exam and Assessment Check list
The two most common problems encountered are a low blood pressure and an indecipherable ECG.
• The endotracheal tube is in proper position.
• patient's oxygen saturation.
• ABG results as soon as they are available.
• Verify correct ventilator settings.
• Check the initial hemodynamic readings
• Check the patient's heart rhythm.
• Check the chest and mediastinal drainage.
• Examine heart sounds. Listen for murmurs
• Check all peripheral pulses.
• Examine the abdomen.
• Check pupillary reflexes.

17. Monitoring in the ICU. From top to bottom: ECG leads, arterial blood pressure
(ABP), pulmonary artery systolic/diastolic waveforms (PAP), central venous pressure (CVP), and pulse oximetry
(SpO2)

18. Labs and tests
Electrocardiogram(EKG)
• ? changed from pre-op
• Rhythm - post-operative bradycardias, blocks, or atrial fibrillation
• ST-T changes –
Diffuse non-specific changes are not uncommon and may reflect pericardial
inflammation
ST elevation in two or more contiguous leads in a territory that was grafted can
indicate an acute graft failure.
ST segment elevation across the anterior leads can represent LIMA spasm if the
LIMA was grafted to the LAD - notify the ICU fellow or Attending immediately.

19. Labs and tests
Chest X-Ray (A portable supine chest x-ray)
Verify correct position of the ETT.
Verify correct position of the Swan-Ganz catheter.
Position of all other tubes and drains(The NG tube, chest tubes)
Mediastinal width.
Check for pneumothorax, lobar collapse, atelectasis, effusions, pulmonary
edema.

20. Labs and tests
Laboratory Results
Hemoglobin
Coagulation parameters (PLT, PT, PTT, INR, ACT)
Renal function assessment
Potassium, magnesium – related with post-operative dysrhythmias. Standing orders are in place to
replace these electrolytes.
Glucose - tight glycemic control post-operatively reduces morbidity. Use an insulin drip or sliding
scale to keep the blood glucose between 6 and 10mMol/L.
Cardiac markers - elevations of CPK, CPK-MB, and troponins etc. are non-specific. They should be
assessed as part of the overall clinical picture including the hemodynamic status of the patient and the
EKG.

21. Warming from hypothermia to 37*C
CPB is usually accompanied by hypothermia to < 32* C. Patients are usually warmed to at least 34* C
before transfer to the ICU.
Effects of hypothermia:
• Predisposes to ventricular dysrhythmias and lowers VF threshold
• Increases SVR; increases afterload and myocardial workload
• Patient shivering causes increased peripheral O2 consumption
• Decreases CO2 production; a patient who has a respiratory alkalosis (low PCO2) on initial ABG
usually will increase their PCO2 with rewarming
• Coagulopathy; impairs platelet function and the coagulation cascade. Rewarming is an important
part of the treatment of a bleeding patient.
• Prolong the duration of action of anesthetic drugs and prolong the time to extubation.
• Increase the risk of wound infection, possibly related to immunosuppression.

22. Warming from hypothermia to 37*C
CPB is usually accompanied by moderate systemic hypothermia to 32–34*C.
The ‘Temperature Afterdrop’ also having role here. It is common practice to
warm patients to 37*C before terminating CPB. Although aggressive
“overwarming” during CPB may also prove detrimental.
• In the ICU, most patients are peripherally vasoconstricted as a
compensatory mechanism to provide core warming.
• Forced-air warming systems (such as the Bair Hugger) are superior to radiant
heaters or warming blankets in increasing the rate of rewarming.

23. The Bair Hugger warming system, used to warm patients arriving in the ICU at
temperatures <36*C.

24. Warming from hypothermia to 37*C
 Other measures, heating intravenous fluids or heated humidifiers in the ventilator
circuit, are of some benefit in preventing progressive hypothermia.
Shivering is associated with hypothermia and increases oxygen consumption and
patient discomfort. Control of shivering with meperidine (25 mg) and
Dexmedetomidine is also effective in controlling shivering.
 Troubleshooting: Rapid rewarm to 37*C and then “overwarm” to higher
temperatures. Narcotics is helpful here. Since warming may lead to profound
peripheral vasodilation and hypotension, concomitant volume infusion can
minimize this problem

25. Bleeding
Bleeding can be divided into:
"Medical" & "Surgical“. Surgical bleeding requires a return to the OR for re-exploration and hemostasis.
Surgical bleeding
Consider a "surgical" source of bleeding in the following situations:
Persistent bleeding in the absence of a specific haemostatic defect (normal coagulation parameters)
Sudden onset of fresh, rapid bleeding.
Greater than 500 cc of bleeding in the first post-op hour.
> 400 cc/hr x 2 hours.
> 300 cc/hr x 3 hours
> 200 cc/hr x 4 hours
If any of the above criteria are noted you must notify the ICU Fellow or Attending and the Cardiac Surgery
Fellow immediately.

26. Bleeding
Etiology of "medical" bleeding:
• Residual heparin effect; patients are anticoagulated before going on CPB with a large dose of
heparin to maintain their ACT >400. A "heparin rebound phenomenon" can also occur several
hours post-op. An ACT will be done as soon as the patient arrives in the ICU. Normal values are
between 100 and 120 seconds.
• Qualitative platelet defects.
• Quantitative platelet defects.
• Clotting factor deficits.
• Fibrinogenolysis.

27. Bleeding
Treatment of "Medical" Bleedings are:
• Correct hypothermia.
• Control BP if elevated.
• Protamine 25 - 50 mg iv if ACT elevated.
• DDAVP 20 mcg iv.
• Platelet transfusion.
• Fresh Frozen Plasma.
• Cryoprecipitate.
• Antifibrinolytic agents.
• Raising the head of the bed or increasing the level of PEEP on the ventilator are also used on occasion.(Controversial)
• PRBC; it is of utmost importance to maintain a hemoglobin level high enough to maintain adequate oxygen delivery.
Guided by hematological laboratory tests including a CBC, PT, PTT, ACT, fibrinogen, and d-dimers.

28. Hemodynamic management
There are numerous causes for hypotension post-operatively. Proper management of the
hypotensive patient in the ICU requires that the precise etiology for the hypotension is
determined and therapy is directed towards reversal of this specific problem.
 Look at the recent hemodynamic parameters.
 Assess the cardiac output/index. Is this a "pump" problem? Or is it due to low SVR?
 Look at the cardiac rhythm.
 Look at the CVP to assess preload.
 Is the afterload high ?

29. Hemodynamic management
Is contractility decreased ?
Is this tamponade? Is this an acute graft occlusion or spasm? Is this an acute dehiscence of a valve repair?
Look at the recent hemodynamic parameters obtained from the Swan-Ganz catheter.
Assess the cardiac output/index.
SIRS - a proportion of patients post CPB will have significant cytokine increases
Sepsis
Anaphylactic or anaphylactoid reactions including protamine reactions,
Drug-induced, toxicological - nitrates, antihypertensives, narcotics and sedatives, etc
Adrenal insufficiency (Was the patient steroid dependent pre-operatively?)
Hyperthyroidism, hypothyroidism,
Neurogenic (spinal) shock

30. Hemodynamic management
If the cardiac index is low ( < 2.0 to 2.2 L/min/m2) then the cause of the hypotension is
inadequate flow or a "pump" problem.
Look at the cardiac rhythm. Absolute or relative bradycardias or tachycardias (commonly new
atrial fibrillation) can lead to decreased C.O. and should be corrected.
Look at the CVP to assess preload. A patient with a low C.I. and a CVP that is "relatively" low
should be given a fluid challenge. Although the CVP in normal individuals varies between 0 and 4
mmHg, patients immediately post-op cardiac surgery commonly have decreased cardiac
compliance for multiple reasons.
If you think the patient may be "preload responsive" (i.e., on the ascending portion of Starling's
curve so that an increase in preload will increase cardiac output), then give the patient a fluid
bolus. The amount is usually between 250 and 500 cc but should be at least enough to raise the
CVP by 3 to 4 mmHg. Both crystalloids (normal saline) and colloids (Pentaspan) can be given.
Remember that PEEP can decrease preload by decreasing venous return.

31. Hemodynamic management
High afterload. Secondary to vasoconstriction and hypertension.
Decreased contractility.This should be managed with inotropic agents while simultaneously looking for the cause.
Low pre-operative ejection fraction
Prolonged CPB time or cross-clamp times, difficulty with myocardial protection intra-op
Acute bypass graft occlusion (check the ECG)
Graft spasm (especially LIMA) - check the ECG for ST elevation
Tamponade .
Acute valvular regurgitation. A valve repair or replacement can rarely have acute dehiscence. Check for a new regurgitant
murmur and new 'v' waves on the PCWP tracing in the case of a MVR.
Inotropes and vasopressors

32. Hemodynamic management
The following is a very simplified approach to the choice of inotropes and
vasopressors. More information can be found at the Critical Care Drug Manual - London Health
Sciences Centre, UWO.
Inotropes
Adrenergic (catecholamine)
Dobutamine - beta-agonist (ß1 >ß2). Increases contractility and HR. ß2 effect can sometimes
decrease SVR and BP. ß1 effect can cause dysrhythmias.

33. • Epinephrine -alpha and beta agonist (ß > alpha). Increases HR, CO, and SVR.
Generally a second-line inotrope. A subset of patients who do not respond to
dobutamine will respond to epinephrine. Potential detrimental effects include
significant increases in myocardial oxygen consumption, increased lactic
acidosis, arrhythmias.
• Dopamine - stimulates dopaminergic, beta, and alpha receptors in dose-
dependent fashion. Inotropic effect (beta-effect) predominates in the 5 to 10
mcg/kg/min range. Notify ICU Fellow or Attending if at 10 mcg/kg/min or
higher. There appears to be little benefit over Dobutamine as an inotrope.

34. Hemodynamic management
Phosphodiesterase inhibitors
Milrinone - phosphodiesterase inhibitors decrease the metabolism (breakdown)
of cAMP. Milrinone increases cardiac output. It also decreases Pulmonary
Vascular Resistance (PVR) and thus can be useful if pulmonary hypertension or
significant right ventricular dysfunction is a problem.
.

35. Vasopressors
Adrenergic (catecholamine)
Norepinephrine (Levophed) -Strong alpha agonist with beta activity as well. Causes vasoconstriction
and thus increases SVR and BP. Negative effects include myocardial and mesenteric ischemia, LIMA
spasm, dysrhythmias, and decreased cardiac output due to afterload increases.
Phenylephrine (Neosynephrine) - Pure alpha agonist.
Peptides
Vasopressin

36. Tamponade
Cardiac tamponade is compression of the heart that impairs ventricular filling
and leads to a low cardiac output. The incidence of cardiac tamponade post-
cardiac surgery has been reported to be as high as 3 to 6 %.
Search for alternate explanations for the low cardiac output (i.e., hypovolemia,
myocardial ischemia, etc.).
Assure patency of the sumps.

37. Tamponade
• Look for "equalization" of central pressures
• Look for a "loss of the y-descent" on the CVP or PCWP tracing.
• Low voltages on the ECG or an increase in the width of the superior mediastinum on serial chest X-rays are
generally poorly sensitive or specific. They are rarely helpful.
• Echocardiogram. This is the best test to assess for tamponade. Often a trans-esophageal Echo (TEE) will be
required because of poor "windows" common in the post-operative state with Trans-thoracic echo (TTE).
• The only treatment for cardiac tamponade is return to the OR, re-sternotomy, and evacuation of the clot
with hemostasis of any ongoing bleeding. Volume resuscitation, inotropes, and vasopressors are temporizing
measures only in this situation.
• If a patient with suspected tamponade suddenly deteriorates and develops PEA (pulseless electrical activity)
an urgent sternotomy should be done in the ICU.

38. Management of Common Postoperative
Scenarios

39. A. Vasoconstriction from hypothermia with hypertension
and borderline cardiac output
• These patients should be managed by a combination of fluid replacement to reach a
pulmonary artery diastolic (PAD) pressure or pulmonary capillary wedge pressure
(PCWP) around 15–20 mm Hg
• Pharmacologic vasodilation to maintain a systolic pressure of 100–120 mm Hg
(mean pressure 70–80 mm Hg), and
• Inotropic support if the cardiac index remains less than 2.0 L/min/m2
• Warming methods noted above should also be employed.
N.B: stopping an inotropic medication in a hypertensive patient without first ensuring that a satisfactory cardiac
output is present can be very dangerous.

40. B. Vasodilation and hypotension during the rewarming phase
• There are several reasons why a patient may vasodilate during the early
postoperative period:
Medications, resolution of hypothermia, improvement in cardiac
output, vasoplegic state of refractory hypotension.
• To avoid hypotension, fluids must be given to maintain filling pressures.
Hypovolemia is a capillary leak syndrome, the use of colloid could be detrimental,
However, if vasodilation of the peripheral and splanchnic beds is the major
problem, then colloids should be preferable, Volume resuscitation is usually required
during the initial 6 hours after arrival in the ICU,

41. B. Vasodilation and hypotension during the rewarming phase
It is generally best to start with a 500 mL bolus of lactated Ringer’s or normal saline.
Nonetheless, the total infusion volume should be limited to 1500–1750 mL (20
mL/kg) per 24 hours. If the patient’s hematocrit is low, a packed red cell transfusion
is the most appropriate means of increasing intravascular volume. If the patient is
bleeding, use of blood component transfusions may be indicated as well.
Beware It must always be remembered that these colloid solutions will also lower the
hematocrit from hemodilution.

42. The following is a general guideline to hemodynamic management during the
rewarming phase.
a. PAD pressure or PCWP to 18–20 mm Hg (often up to 25 mm Hg in hypertrophied hearts) using crystalloid
and then colloid. Once this level is reached, if the patient remains hypotensive, if the urine volume begins to match the infused
volume, or if more than 2000 mL of fluid has been administered and filling pressures are not rising, consider the following:
i. If CI >2.2 L/min/m2
use phenylephrine , or if unsuccessful, vasopressin for a potential “vasoplegic” state
ii. If CI is 1.8–2.2 L/min/m2
use norepinephrine
iii. If CI <1.8 L/min/m2
use an inotrope, then norepinephrine prn
b. Note: Use of an α agent may not be able to minimize a capillary leak, but it does counteract vasodilation. This may decrease
the volume requirement and improve SVR and blood pressure with little effect on myocardial function.

43. C. Low cardiac output syndrome with impaired left ventricular function
1. Isolated left ventricular dysfunction requiring post cardiotomy inotropic support may be noted in patients with
preexisting LV dysfunction from a remote or recent myocardial infarction or advanced valvular heart disease, or in
patients with active ischemia going into the operating room
2. Appropriate measures should be taken at the conclusion of surgery to assess and optimize a patient’s hemodynamic
status before arrival in the ICU, including pacing, optimal preload, inotropic support, and use of an IABP, if indicated.
3. In addition to careful examination and standard monitoring of critically ill patients, echocardiography in the ICU is
very beneficial in clarifying potential problems

44. D. Normal left ventricular function but low cardiac output
(diastolic dysfunction and right ventricular failure)
This scenario is noted most commonly in small women with systemic
hypertension who have small, hypertrophied left ventricles, aortic stenosis
and hyperdynamic hearts that manifest near cavity obliteration.
The hemodynamic data derived from the Swan-Ganz catheter typically show
elevated filling pressures and a low cardiac output, suggestive of left
ventricular dysfunction.
 Transesophageal echocardiography (TEE) has been invaluable in the
assessment and management of this problem.

45.  Lusitropic drugs that relax the left ventricle should be substituted for
catecholamines that have beta-adrenergic inotropic and chronotropic properties.
Milrinone may be beneficial in this regard and can support RV function as well.
Nesiritide exerts lusitropic properties that may be the mechanism of its
pulmonary vasodilatory effects.
Other considerations include use of low-dose calcium channel blockers or
beta-blockers to improve diastolic relaxation, although it is conceptually
difficult to start these when the cardiac output is compromised. Aggressive
diuresis to reduce interstitial edema while providing colloid (salt-poor albumin)
to maintain intravascular volume may also improve diastolic relaxation.

46. Postoperative Considerations Following Commonly
Performed Procedures

47. A. On-pump coronary artery bypass grafting (CABG)
1. If the patient is otherwise hemodynamically stable, it is advisable to start a
vasodilator rather than give additional sedation or narcotics to control
hypertension, in order to minimize respiratory depression.
2. combination of hypertension and tachycardia with a supranormal cardiac output
can be managed by b-blockers (esmolol or intermittent doses of IV metoprolol).
3. Patients with a hyperdynamic left ventricle allowing the blood pressure to drift up
to 140 mm Hg systolic and then using b-blockers to control both the tachycardia
and the hypertension.

48. A. On-pump coronary artery bypass grafting (CABG)
4. Atrial and ventricular pacing wires should be placed in all patients
undergoing CABG. If the patient has……..
• sinus bradycardia or a junctional rhythm, atrial pacing at 90 beats/min.
• normal AV conduction, it is always preferable to use atrial pacing rather than AV sequential
pacing,
• second- or third-degree heart block is present, pacing in the DVI or DDD mode is appropriate.
• patients with moderate-to-severe LV dysfunction, biventricular pacing
• the patient has a slow ventricular response to atrial fibrillation, VVI pacing should be initiated

49. A. On-pump coronary artery bypass grafting (CABG)
5. Use of nitroglycerin to control hypertension will reduce preload and cardiac
output because of its venodilatory effects.
6. Inotropic support is usually initiated at the termination of bypass and may be
required for several hours in the ICU to support cardiac output during the early
phase of transient myocardial dysfunction. The initial first-line drug may be
epinephrine, dobutamine, or dopamine. Sometimes IABP is needed.
7. A common practice is to initiate antiarrhythmic therapy with lidocaine in the
operating room to suppress ventricular arrhythmias

50. A. On-pump coronary artery bypass grafting (CABG)
8. Non sustained VT in patients with an ejection fraction >35% is best managed with
b-blockers. In patients with a low ejection fraction, an electrophysiologic study may be
indicated, and placement of an implantable cardioverter-defibrillator (ICD) may be
considered.
9. Atrial fibrillation (AF) is noted in about 25% of patients following CABG.
Most centers initiate b-blockers; (metoprolol 25–50 mg bid),
Magnesium sulfate
Amiodarone (prophylactic)

51. A. On-pump coronary artery bypass grafting (CABG)
10. Close observation of EKG and perioperative MI
11. For patients receiving radial artery grafts, a vasodilator is used to prevent
graft spasm. A variety of “cocktails” including nitroglycerin with verapamil or
nicardipine are used during preparation of the conduit, and diltiazem 10 mg/h
IV or nitroglycerin 10–15 mg/min (0.1–0.2 mg/kg/min) is given
intraoperatively and continued for 18–24 hours postoperatively.
12. Antiplatelet therapy

52. B. Off-pump coronary artery bypass grafting (OPCAB)
1. Patient temperature tends to drift during surgery and must be maintained by having a
higher temperature in the operating room, warming all intravenous fluids and using a
topical warming device, such as the Bair Hugger or Kimberly-Clark temperature-
controlling system. The Thermogard endovascular heating system (Alsius Corporation).
2. low doses of inotropes are commonly used during surgery, especially in patients with
impaired ventricular function, and should be continued until a satisfactory output can be
maintained.
3. The immediate postoperative ECG must be evaluated.
4. Pacing
5. Management of AF

53. B. Off-pump coronary artery bypass grafting (OPCAB)
6. Extubation in OT or soon after in ICU
7. Fluid management
8. Correction of anaemia
9. Antiplatelet therapy

54. C. Aortic valve surgery
1. Aortic stenosis:
a) atrial or AV pacing be used. The optimal heart rate is probably around 90–100
bpm for patients with LVH.
b) Adequate preload must be maintained (PCWP often > 20 mm Hg) to ensure
adequate left ventricular filling.
c) Hypertension tends to develop after several hours in the ICU and must be
controlled to reduce myocardial oxygen demand and protect the aortic suture line.
Use of vasodilators for a hyperdynamic heart may reduce diastolic perfusion
pressure and produce a tachycardia. A b-blocker, such as esmolol, is beneficial in
this situation.

55. C. Aortic valve surgery
d) TEE in the operating room can define the nature of the pathophysiology
and direct management appropriately. Volume infusions to improve left
ventricular filling are beneficial despite the high filling pressures, but
initiation of inotropic support with catecholamines for a low cardiac output
state is counterproductive. Milrinone or nesiritide might be beneficial
because of their lusitropic effects that promote ventricular relaxation.

56. C. Aortic valve surgery
2.Aortic regurgitation:
Despite the placement of a competent aortic valvular prosthesis, most
patients with AR remain vasodilated after surgery and require the use of an
alpha-agent, such as phenylephrine or norepinephrine, to maintain a
satisfactory blood pressure. Systolic hypertension is often better controlled
with b-blockers than with vasodilators.

57. C. Aortic valve surgery
Heart block :
• May complicate an aortic valve replacement (AVR) because of edema, hemorrhage, suturing,
or debridement near the conduction system.
• Epicardial AV pacing may be necessary for several days.
• The presence of a bundle branch block following AVR is of adverse prognostic significance.
If complete heart block persists for more than a few days, during which time edema or
hemorrhage should subside, placement of a permanent DDD pacemaker should be
considered.
• The overall incidence of pacemaker placement following AVR is about 5%
Anticoagulation:

58. D. Mitral Valve Surgery
Mitral stenosis:
• Most patients with MS have a small left ventricular cavity with preserved function
• Hemodynamic support may be required more commonly for RV than LV dysfunction.
• Postoperative ventilatory failure is common in patients with chronic MS as a result of
pulmonary hypertension, fluid overload, and chronic cachexia with poor ventilatory reserve.
Management: Aggressive diuresis, nutritional support, and a plan for
ventilatory support and weaning are essential.
• Most patients with MS are diuretic-dependent. They should be maintained on diuretics for
several months after discharge.

59. D. Mitral Valve Surgery
Mitral Regurgitation:
“afterload mismatch” may result in LV failure and require inotropic support and systemic unloading with vasodilators.
Right ventricular dysfunction:
a) Isolated RV dysfunction, use of volumetric Swan-Ganz catheters can better define the degree of RV dysfunction.
b) The initial management of RV dysfunction is fluid administration to optimize preload.
c) Inotropic drugs should be given to support both RV and LV performance. Preferably, those that can also reduce the
PVR, such as milrinone, should be chosen.
d) Nesiritide is very effective in reducing PA pressures with minimal effect on the
systemic circulation.
e) In patients with severe RV dysfunction, selective pulmonary vasodilators may improve
RV function by lowering RV afterload.

60. D. Mitral Valve Surgery
Left ventricular Dysfunction:
1. To optimize the systemic output, the LV volume status usually has to be maintained at fairly
high levels.
2. Assessment of LV end-diastolic volumes is difficult using Swan-Ganz catheter
measurements
3. It is generally best to correlate the PAD pressure with direct observation of LV volumes by
TEE at the conclusion of surgery.
Left ventricular outflow tract obstruction (LVOTO): It has been described following mitral valve
replacement due to strut malposition in the outflow tract, in patients with small LV cavities or
septal thickening, and most commonly with retention of the anterior mitral leaflet.

61. Key Concepts
Cardiac surgery involves unique anatomic and physiologic stresses that tax the reserve
of every organ system. Continuous postoperative surveillance is required for early
recognition of pathology and for rapid institution of organ and life-preserving
therapies.
Cardiac surgery causes transient (lasting 12–24 h) myocardial injury, sympathetic
hyperreactivity, and the systemic inflammatory response syndrome (SIRS) in nearly all
patients. As a result, hemodynamic instability requiring transient pressor and/or
vasodilator infusions and intravascular volume expansion should be expected in all
patents during the first 6 to 24 postoperative hours.

62. Key Concepts
Atrial fibrillation/flutter occurs in 30 percent of patients after cardiac surgery,
and its incidence can be reduced by half through prophylactic administration
of β-blockers, amiodarone, or sotalol.
Significant pulmonary compromise should be expected in all cardiac surgical
patients postoperatively, with 5 percent of patients experiencing overt
respiratory failure. Diuresis should be instituted as soon as SIRS abates to limit
fluid accumulation in the injured post-CPB lung.

63. Key Concepts
Liberation from mechanical ventilation should be sought at the earliest possible time in
all patients. Extubation in most patients can be achieved as soon as they are awake
enough to maintain airway patency and achieve adequate spontaneous gas exchange. In
patients with significant respiratory compromise, daily assessment of a spontaneous
breathing trial is the best method to assess readiness for extubation.
Aggressive glucose control with a goal of 100 to 140 mg/dL within 24 h of ICU
arrival reduces the incidence of death, sepsis, and renal failure after cardiac surgery.

64. For further reading…….
1. Johns Hopkins Textbook of Cardiothoracic Surgery, 2nd edition
David D. Yuh, MD, FACC, FACS; Luca A. Vricella, MD, FACS; Stephen C. Yang, MD; John R. Doty, MD
2. Manual of perioperative care in adult cardiac surgery, 5th edition
Robert M. Bojar, MD

65. Thank you all