coronary artery bypass graft on cardiopulmonary bypass pump

1. ANAESTHESIA FOR CABG
ON CPB
SPEAKER : DR. SHEKHAR ANAND
MODERATOR : DR. R K DUBEY

2. CABG
•Coronary artery bypass grafting is performed
for patients with coronary artery
disease(CAD) to improve quality of life and
reduce cardiac related mortality.

3. 1. Basic circuitry.
2. Pre-operative evaluation
3. Intra-op monitoring
4. Anaesthetic delivery
• Premedication
• Induction
5. Pre-cardiopulmonary bypass period
6. Maintenance of bypass
7. Myocardial protection
8. Preparation from weaning
7. Weaning from the bypass.
8. Events in post bypass period.
An Overview

4. INDICATION OF CABG
CABG is performed for both symptomatic and prognostic reasons. Indications for CABG
have been classified by the American College of Cardiology (ACC) and the American Heart
Association (AHA) according to the level of evidence supporting the usefulness and efficacy
of the procedure..
▪ Class I - Conditions for which there is evidence and/or general agreement that a given
procedure or treatment is useful and effective
▪ Class II - Conditions for which there is conflicting evidence and/or a divergence of opinion
about the usefulness or efficacy of a procedure or treatment
▪ Class IIa - Weight of evidence or opinion is in favour of usefulness or efficacy
▪ Class IIb - Usefulness or efficacy is less well established by evidence or opinion
▪ Class III - Conditions for which there is evidence and/or general agreement that the
procedure/treatment is not useful or effective, and in some cases it may be harmful

5. INDICATION OF CABG
Class I indications for CABG from the American College of Cardiology (ACC) and the
American Heart Association (AHA) are as follows
▪ Left main coronary artery stenosis >50%
▪ Stenosis of proximal LAD and proximal circumflex >70%
▪ 3-vessel disease in asymptomatic patients or those with mild or stable angina
▪ 3-vessel disease with proximal LAD stenosis in patients with poor left ventricular (LV)
function
▪ 1- or 2-vessel disease and a large area of viable myocardium in high-risk area in
patients with stable angina
▪ >70% proximal LAD stenosis with either ejection fraction < 50% or demonstrable
ischemia on non-invasive testing .

6. INDICATION OF CABG
Other indications for CABG include the follo
▪ Ongoing ischemia in the setting of a non–ST segment elevation MI that is
unresponsive to medical therapy (Class I).
▪ Poor left ventricular function but with viable, non-functioning myocardium above
the anatomic defect that can be revascularized.
▪ CABG may be performed as an emergency procedure in the context of an ST
segment elevation MI (STEMI) in cases where it has not been possible to perform
percutaneous coronary intervention (PCI) or where PCI has failed and there is
persistent pain and ischemia threatening a significant area of myocardium despite
medical therapy.

7. CPB is a technique that diverts venous blood away from the heart (most
often from one or more cannulas in the right atrium), adds oxygen,
removes CO 2 , and returns the blood through a cannula in a large artery
(usually the ascending aorta or a femoral artery). As a result, nearly all
blood bypasses the heart and lungs.
CARDIO PULMONARY BYPASS (CPB)

8. 1. BASIC CIRCUIT
The typical CPB machine has six basic components:
1. Venous reservoir,
2. An oxygenator,
3. Heat exchanger,
4. Main pump, and accessory pump,
5. An arterial filter,
6. Tubing-conducts venous blood to the venous reservoir, and
7. Tubing that conducts oxygenated blood back to the patient
Modern machines use a single disposable unit that includes the reservoir, oxygenator,
and heat exchanger

11. Heart lung machine

12. Venous Cannula
Arterial
Cannula
Venous
Reservoirs

13. Roller Pumps Centrifugal Pump

14. Arterial filter Cardioplegic pump

15. PRIMING
• Prior to its use, the CPB machine must be primed with fluid (1200-1800 mL) that is
devoid of bubbles.
• Usually a balanced salt solution is used to flush the machine, but sometimes Albumin or
Hespan is added.
• Blood is also used as a priming solution for small pediatric patients or for anemic adult
patients.
• At the onset of bypass, hemodilution usually decreases the hematocrit to about 22-25%
in most patients.
• That is why in more critically ill or anemic patients, blood is used for priming the CPB
machine to avoid too drastic a drop in hematocrit and consequently compromising O2
delivery and leading to Ischemia.

16. HYPOTHERMIA
Intentional hypothermia is routinely used following initiation of CPB
Core body temp. Is usually reduced to 20-32 degrees C
Metabolic O2 demands are generally cut in half with each reduction of 10
degrees C in body temp
Profound hypothermia to 15-18 degrees C allows total circulatory arrest for
complex repairs of the aorta for up to 60 min.
During that time, both the heart and cpb pump are stopped

17. • Hypothermia is NOT w/o its problems
• Profound hypothermia can be associated with:
1) Platelet dysfunction
2) Reduced serum ionized calcium
3) Reversible coagulopathy
4) Depression of myocardial contractility

18. MYOCARDIAL PRESERVATION
• Optimal surgical results depend on prevention of myocardial damage and
maintenance of normal cellular integrity and function during CPB
• Nearly ALL patients sustain some myocardial damage during CPB
• Proper preservation techniques can keep this damage to a minimum

19. MYOCARDIAL PRESERVATION
• Inadequate myocardial preservation usually manifests at the end of CPB as a
persistently LOW CO, EKG signs of ischemia, or cardiac arrhythmias
• Aortic cross-clamping during CPB completely cuts off coronary blood flow
• Although no studies have really been done to determine an optimal time for cross-
clamping, it is believed that cross-clamp times GREATER than 120 min. Are
generally considered as undesirable

20. CARDIOPLEGIA
The most widely used method or arresting the myocardium and
decreasing O2 demand is through the use of a solution high in K+
called “cardioplegia”
Following initiation of CPB, induction of hypothermia and cross-
clamping of the aorta, the coronary circulation is periodically perfused
with cold cardioplegia

21. CARDIOPLEGIA
To provide a motionless field for surgery, heart is stopped in diastole
by administering a potassium rich cardioplegia soln.
It interrupts myocardial electromechanical activity, reduces oxygen
consumption by 90% and cold cardioplegia soln. Reduces it by 97%.

22. CARDIOPLEGIA
 For most complete cardioplegia , both antegrade (through aortic root) and
retrograde(through coronary sinus) approach is used
Arrest can be reversed by reperfusing heart by warm normokalemic blood
(hot shot)

23. POTASSIUM CARDIOPLEGIC SOLUTIONS
BASIC COMPONENTS REMARKS
1. Potassium (10-40 mEq/L) Decreases transmembrane potential
2. Sodium <140 mEq/l (conc<plasma) Ischemia increases intracellular sodium
3. Calcium 0.7-1.2 mmol/l Maintain cellular integrity
4. Magnesium 1.5-15 mmol/l control excessive intracellular influxes of calcium
5. Buffers- Bicarbonate, Histidine, Tromethamine
(THAM)
prevent excessive buildup of acid metabolites
6. Hypertonic Agents-mannitol control cellular edema
7. Lignocaine And Glucocorticoids Membrane Stabilizing Agents
8. Glucose, Glutamate, Aspartate Energy Substrates
9. Vehicle/Solvents Crystalloids Or Blood(more Common)

24. CARDIOPLEGIA
• Since the cardioplegia cannot reach areas of the heart that are distal to the
coronary artery obstructions, many surgeons also administer cardioplegia
retrograde through a coronary sinus catheter and back through the venous
system
• Some studies have reported that the combination of antegrade and retrograde
cardioplegia is FAR superior at protecting the myocardium as compared to
only antegrade administration

25. CARDIOPLEGIA
• Cardioplegia is usually administered every 20-30 minutes while the patient is on
CPB
• Excessive cardioplegia can result in an absence of electrical activity, AV conduction
blockade, or a poorly contracting heart at the conclusion of CPB
• There is often a period of “wash out” needed after long cases at which time the heart
is allowed to return beating while still on partial CPB to allow excess cardioplegia
and cellular byproducts to become eliminated and allow the myocardium to contract
fully and without any depression

26. • History and physical examination to evaluate LV dysfunction and LV/RV
failure, respiratory disease, prior cardiac surgery
• Chest radiograph to detect resp. disease, CHF, abnormal cardiothoracic
ratio etc
• Resting ECG to detect rhythm disturbances, conduction defects, decision of
intra-op lead selection
Preoperative Evaluation

27. • Exercise ECG showing significant ST segment changes in early stages, sustained
changes, abnormal changes in HR or BP, development of angina or arrythmia indicate
severe CAD
• ECHO shows segmental wall motion abnormality
• Stress ECHO with exercise or dobutamine and contrast ECHO detect abnormal areas of
perfusion
• Myocardial perfusion scans using thallium-201 or tc 99m locate and quantitate
ischemic areas

28. • Angiography defines location and degree of occlusion and coronary artery spasm
• Contrast ventriculography shows areas of hypokinesia, akinesia and dyskinesia
• Ejection fraction= edv-esv/edv [n-50-75%]
25-50%- symptoms on exercise
<25% - LVF symptoms at rest

29. IV ACCESS
• In the preop suite prior to induction, place AT LEAST an 18g, preferably a
16g, IV cath.
• Once the IV cath is placed, premedication can be given and then the arterial-
line is placed.
• This is the minimum needed prior to induction
• In sicker patients, an introducer and an SwanGanz catheter need to be placed
as well ALL prior to induction of anesthesia.

30. MONITORING
• The following monitors are usually used during a CABG procedure:
1) EKG (at least a minimum of 2 leads, II and V5)
2) O2 sat
3) BP cuff
4) Temp
5) Etco2
6) A-line (for abg’s and continuous BP; placed PREOP)
7) SG cath (with or without fiberoptics to calculate CO and to sample mixed venous blood or to get
a continuous readout of MVO2 sat)
8) TEE
9) BIS

31. INTRA-OP MONITORING
• IBP- dominant hand radial art preferred
• ECG- ST segment changes or new T wave changes are diagnostic of ischemia
• Simultaneous observation of an inferior lead [II, III, AVF ] and anterior lead [V4,V5]
detects approximately 90% of events.
• Posterior heart ischemia is difficult to detect

32. • Cvp – Internal jugular vein
• PA CATHETER- appearance of new V wave in pulmonary artery pressure waveform
indicates development of Mitral Valve Regurgitation due to ischemic papillary muscle
dysfunction
 Important in post-op period where TEE can not be used
 Intra-op monitoring may require frequent balloon inflations

33. Can assess regions supplied by all three major coronary arteries
• Regional wall motion abnormality can precede ECG and PA wave form changes
• Intra-op stress TEE with low dose dobutamine can demonstrate myocardial
contractile reserve and helps revascularize myocardium that will be benefited from
increased blood supply
• Contrast TEE [using microbubbles] also avoids needless therapeutic intervention
Transesophageal Echocardiography

34. ANTICOAGULATION
• Anticoagulation must be established prior to CPB to prevent acute DIC and formation
of clots in the CPB pump
• The adequacy of anticoagulation MUST be confirmed by a test called an ACT
(activated clotting test)
• An ACT longer than 400-480 sec is considered SAFE at most centers
• Anticoagulation is achieved by heparinization

35. • Heparin 300-400u/kg is administered through a central vein targeting ACT level
min of 480s
• ACT is the time from adding whole blood to a tube containing a contact phase
activator (celite or kaolin) up to the time when first clot appears.
• Repeat act is measured after 5 mins and if it is less, 100u/kg is to be administered
again.
Heparinization

36. BLEEDING PROPHYLAXIS
• Bleeding prophylaxis with antifibrinolytic agents may be initiated before or after anticoagulation ,
preferably after.
• The antifibrinolytic agents: ε-aminocaproic acid and Tranexamic acid, not affect the ACT and only
rarely induce allergic reactions.
• Ε-aminocaproic acid = as 50–75 mg/kg( loading dose )
• 20–25 mg/kg/h (maintenance infusion)
• some clinicians use a standard 5–10 g loading dose followed by1 g/h)
• Tranexamic acid is often dosed at 10 mg/kg followed by 1 mg/kg/h,
• Intraoperative collection of platelet-rich plasma by pheresis prior to CPB is employed by some
centers; reinfusion following bypass may decrease bleeding and reduce transfusion requirements.

37. PREMEDICATION
• Pain and anxiety: narcotic or anxiolytic agent or both.
• Supplemental intra-venous drugs- commonly midazolam and fentanyl- are often necessary
during radial artery cannulation before induction of anesthesia.
• Patients with low cardiac output secondary to CHF sedation should be performed judiciously
to avoid myocardial depression and resultant hypotension.
• Patients with an EF <40% should be given preop medications slowly and carefully since they
are much more sensitive to the hypotensive effects of the meds

38. Goal is to avoid undue hypotension and to attenuate hemodynamic response
to laryngoscopy and intubation
Hypotension may be due to hypovolemic state and reduction in sympathetic
tone in response to inducing agents particularly in patients with poor lv
function.
Fall in B.P >20% of baseline needs use of inotropes
Induction

39. • Hypertension may be due to pre-induction anxiety and sympathetic stimulation
• All anesthetic agents except ketamine cause decreased blood pressure by
 Decreasing sympathetic tone
 Systemic vascular resistance
 Inducing bradycardia or
 Directly depressing myocardial function

40. • Selected agent should be given in small incremental doses and titrated first
against loss of consciousness then to an acceptable fall in BP
• Muscle relaxation and controlled ventilation ensures adequate oxygenation
and prevents hypercapnia

41. • Fentanyl 50-100 mcg/kg or sufentanil 15-25mcg/kg
• Produces prolonged post-op respiratory depression, high incidence of
awareness, rigidity, fail to control hypertensive response to stimulation
High dose narcotics

42. TOTAL INTRAVENOUS ANESTHESIA-
• Infusion of PROPOFOL,0.5-1.5 mg/kg f/b 25-100 mcg/kg/min and
• REMIFENTANIL 1 mcg/kg bolus f/b 0.25-1 mcg/kg infusion.
• Total dose of fentanyl should be 5-7 mcg/kg
• Use of short acting agents results in early extubation and lesser hospital stay
• Drugs are costlier and remifentanil should be supplemented by morphine at
the end for post operative pain relief.

43. • Midazolam 0.05 mg/kg for sedation.
• Propofol 0.5-1.5 mg/kg or Etomidate(0.1-0.3 mg/kg) for induction.
• Opioids are given intermittently and total dose of fentanyl and remifentanil
should not exceed 15 and 5 mcg/kg respectively (fast track management).
Mixed intravenous

44. INHALATION ANESTHESIA
• Volatile agents{0.5-1.5 MAC for maintenance of anesthesia and sympathetic response
suppression(MACBAR)}
• Isoflurane , sevoflurane or desflurane are used for maintenance
• It results in easy control of depth of anesthesia and hemodynamic stability and early
extubation
Others-
In frail patients, combination of ketamine and midazolam provides hemodynamic
stability, good amnesia, analgesia and minimal respiratory depression

45. 1. Check bilateral breath sounds
2. Adjust fresh gas flow
3. Check pressure points
4. Protect eyes
5. Check all monitors and tubings after final position
6. Administer antibiotics
7. Check baseline ACT
8. Check baseline blood gas parameters, electrolytes and hematocrit by doing ABG
1. Pre cardio-pulmonary bypass period

46. 9. Skin incision can cause sympathetic stimulation, so adequate depth of anesthesia is
necessary
10. Sternal incision and splitting accompanies high level of sympathetic stimulation
11. Sternal splitting can cause:
a. Awareness and recall, so amnesic agents like benzodiazepines or propofol is to be used
b. Tachycardia & raised BP can be treated by nitroglycerine boluses or by esmolol
c. Pain --high doses of fentanyl can be use
12. Lungs are to be deflated during sternal splitting to avoid damage.
• Sternal splitting can cause kinking or mal-positioning of PA cath.
• Dissection of post -ganglionic sympathetic fibres from aorta to cannulate it can cause

47. Hypotension-may be due to:
 Hypovolemia
 Decreased venous return due to increased airway pressure , tension pneumothorax ,
handling of heart and great vessels
 Impaired myocardial contractility
 Ischemia
 Dysarrythmia
 Measurement error due to kinked catheter, wrist positioning error etc.
Hemodynamic changes

48. T/T OF HYPOTENSION
 Rule out technical and mechanical factors
 Check for dysarrythmia
 Use of inotropes
 Fluid loading
 Decrease inhalational agents

49. May be due to:
 Light anesthesia
 Hypercapnia
 Hypoxia
 Hypervolemia
T/T of hypertension-
• Increasing anesthetic depth
• Vasodilator agents like nitroglycerine, nitroprusside
• Using b-blockers
Hypertension

50. May be due to
 Vagotonic effects of narcotics
 Use of b-blockers
 Hypoxia
 Ischemia
T/t of bradycardia
• Is indicated if there is fall in BP or HR <40 even with no fall in bp
• Atropine 0.4-0.6 mg i.v is indicated
Sinus Bradycardia

51. May be due to:
 Light anesthesia
 Hypovolemia, anemia
 Inotropic drugs , pancuronium ,
isoflurane
 Hypoxia
 Hypercapnia
 Ischemia
Management of tachycardia includes
Checking ventilation abnormalities
Increasing depth of anesthesia
Volume loading
Using b-blockers
Sinus Tachycardia

52. DYSRHYTHMIAS
May be due to:
 Mechanical stimulation of heart
 Pre-existing dysrhythmia
 Electrolyte imbalance
 Increased catecholamines
 Ischemia
These can be treated by treating underlying causes, using lidocaine , b-blockers and by
synchronized cardioversion

53. • PRIMING of circuit is to be done by balanced salt solution(1200-1800ml for adults
• Other components like albumin or hetastarch, mannitol, heparin and bicarbonate are
added
• It decreases hematocrit to 22-25%
• In patients who are severely anemic or pediatric patients blood is used as prime
• In patients with sufficient hemoglobin auto transfusion is done after termination of CPB

54. Benefits of hemodilution-
• Decreased viscosity improves microcirculation and compensates for increased
viscosity due to hypothermia
Risks-
• Decreased SVR decreases BP
• Dilution of drugs and coagulation factors
• Low oncotic pressure increases fluid shifts and edema formation
• Decreased oxygen carrying capacity

55. • Aortic cannula is inserted first to allow rapid volume infusion in cases of
hemorrhage during venous cannulation
• SBP is lowered to avoid risk of dissection and PEEP applied to avoid air
entrainment by increasing intra-cardiac pressure
Cannulation

57. • Anticoagulation (min ACT of 480sec) is needed
• Position of cannulae is to be checked .
• Urine noted and urobag is to be emptied
• Equality of carotid pulse is to be checked
• Supplemental doses of anesthetic agents are to be administered to compensate for
dilution
• All i.v. lines are to be closed to avoid hemodilution
Prebypass checklist

58. • Face is to be checked for color , edema , conjunctival chemosis
• PA pressure should be less than 15 mm hg
• Arterial blood pressure should be mean 30-40 mm hg
• CVP should be<5 mmHg.
• Cardiac contractility and distensibility is to be checked
Initial bypass checklist

59. • ACT repeated every 30-60 mins, if less supplemental heparin is added
• Blood gas values to be evaluated every 30-60 mins
• Pao2 maintained between 100-300 mm hg & paco2 between 35-40 mm hg.
• Blood glucose and hematocrit is measured every 30-60 min
Maintenance of bypass

60. • Sufficient anesthetic depth is maintained to prevent awareness, spontaneous
movement, hypertensive and tachycardic responses
• Depth maintained by adding anesthetic agents and muscle relaxants directly
into the circuit and adding volatile agents by connecting vaporizer to
oxygenator

61. • Intra operative awareness may be due to underdosing, dilution or absorption
of drugs and increased requirement during rewarming
• It can be prevented monitoring BIS and supplementing drug
• Ventilation should cease when total bypass begin

62. • Pump flow rate is to be maintained at 50-70 ml/kg/min or 2.2-3.1
l/min/square mt
• Urine output should be at least 0.5ml/kg/hr
• Core temp. is to be monitored at nasopharynx or tympanic membrane
(jugular bulb temp is gold standard)
• De-airing of heart is to be done before weaning from CPB by increasing
venous pressure by inflating lungs

63. Pneumonic is CVP
• COLD- patient’s temp. Should be 36-37 degrees, hyperthermia is
deleterious
• Conduction- HR of 80-100 bpm is optimal, bradycardia may need epicardial
pacing wire for AV pacing or inotropes, tachycardia needs t/t of cause, AV
block may need AV pacing and supraventricular tachycardia needs
pharmacotherapy and cardioversion

64. • Contractility is estimated by TEE and CO by PA catheter
• Cells- Hb should be at least 7-8g%
• Coagulation- long bypass period and extreme hypothermia increase risk,
PT,PTT,PC should be normal
• Ventilation of lungs- must be established after PA blood flow is restored

65. • VISUALISATION of heart and TEE for regional and global contractility
• VOLUME expansion- if necessary
• PACER AND PRESSOR AGENTS should be readily available
• POTASSIUM must be corrected as hypokalemia can cause dysrhythmias and
hyperkalemia can cause conduction blocks

66. • Before termination, patient should be rewarmed, heart is de-aired, regular
cardiac electrical activity confirmed or supported by pacemaker, lab values
confirmed and corrected
• Ventilation of lungs is established, venous drainage is slowly reduced and
cardiac filling volume is gradually increased
• Vasopressors or inotropic support may be needed
Weaning from bypass

67. • When patient becomes hemodynamically stable, protamine is administered to
reverse anticoagulation
• 1-1.3mg of protamine per 100 units of heparin is administered slowly over
10-15 mins
• ACT should be brought to baseline values
• When pre-loading is optimal and contractility is adequate, aortic inflow line
is clamped to separate from bypass

68. • Elevated BP should be avoided to prevent stress on suture lines
• If CO is not optimal, preload can be increased in 100ml increments as
rewarming is associated with vasodilation
• Increase in hemodynamic instability and use of inotropes may need
reinstitution of CPB

69. 1. Cardiovascular decompensation-
Ischemia and infarction may be due to:
• Thrombosis or particulate or air emboli in graft
• Kinking or spasm of graft
• Incomplete revascularization due to distal disease
• Inoperable vessels
Events in post bypass period

70. LV dysfunction is amenable to combination of ionotropes and vasodilators to increase
CO
RV dysfunction may be due to inadequate protection, ischemia, infarction, pulmonary
air emboli, preexisting pulmonary HTN
RV failure needs inotropic support as well as pulmonary vasodilation nitroglycerin,
nitroprusside, prostaglandin E1 (PGE1), b-type natriuretic peptide (eg, Nesiritide),
sildenafil, or inhaled agents such as nitric oxide and prostacyclin (prostaglandin I2
[PGI2, epoprostenol])

71. Hypotension may be due to low svr, severe anemia, low viscosity, acid-base
disturbances and is treated with vasoconstrictors
Dysrhythmias - AF is most common and converted to sinus rhythm by
synchronized cardioversion, amiodarone etc.
VF or flutter needs defibrillation and drugs like amiodarone and lidocaine
Bradycardia and heart block need AV sequential pacing by epicardial pacing wires

72. • Inadequate surgical hemostasis is most common cause
• Platelet dysfunction due to hemodilution, hypothermia, contact activation,
adhesion and sequestration.
• Activation of coagulation cascade by contact factors
• Fibrinolysis by release of t-pa from damaged endothelium
2. Bleeding and coagulopathy

73. Consumption of factors
Treated by FFP and platelet concentrates
Thrombo-elastography is routinely done in some centres to identify the
causes of bleeding after CPB.

74. • Atelectasis causing decreased oxygenation, lungs are to be reinflated by
hand before machine ventilation
• Hemothorax, pneumothorax may need chest tube insertion
3. Pulmonary complications

75. • Cardiogenic pulmonary edema due to fluid overload in patients with
preexisting HF
• Noncardiogenic pulmonary edema due to inflammatory response, multiple
emboli, increased permeability, transfusion reaction

76. • Hypokalemia due to diuretics, mannitol, hyperglycemia treated with insulin :-
treated with kcl @ 10-20 meq/hr
• Hyperkalemia due to cardioplegia, blood products, impaired renal function:-
treated with hyperventilation, calcium, diuretics, glucose and insulin infusion
4. Metabolic disturbances

77. Hypocalcemia due to citrate in blood products, hemodilution, alkalosis:-
treated with 10% calcium chloride 5-10mg/kg
Hypomagnesemia due to hemodilution:- treated with 2-4 g of magnesium
Hyperglycemia is deleterious and is due to stress of surgery and
inflammatory response, glucose level > 200mg/dl:- should be treated with
insulin

78. • MC complication is transient neuropsychiatric dysfunction, strokes are
uncommon
• Causes are micro and macro emboli, global hypo-perfusion, cerebral
hyperthermia, cerebral edema, inflammation, BBB disruption
• Intra-op awareness should be avoided
6. Effect on CNS

79. • Hypothermia causes increase in SVR, shivering increasing oxygen consumption
and coagulopathy
• So normothermia should be achieved at end of bypass
• Rewarming should be gradual
• Hyperthermia should be avoided as it delays neuronal metabolic recovery,
increases excitotoxic neurotransmitter release, oxygen free radical production,
intracellular acidosis, increased BBB permeability
Temperature regulation

80. • Fluid loss, myocardial depression and vasodilation by anesthetic agents, long
term use of aceis, inflammatory response, loss of pulsatile flow decrease
renal perfusion
• Fluid replacement, vasoconstrictors, frusemide 10-20 mg or mannitol 0.5-
1mg/kg can be used
Renal effects

82. TRANSPORT FROM OT
Complications during transport-
• Inadvertent extubation
• Pull off of monitors
• Loss of i.V lines
• Injury to body parts
• Disconnection of pacemaker wires
• Chest tube, foleys dislodgement
• Removal of arterial line and PA catheter

83. • Portable monitoring equipment,
• Infusion pumps,
• Full oxygen cylinder with a self-inflating bag for ventilation should be ready
• Upon arrival to icu patient is attached to ventilator,
• Breath sounds checked,
• Orderly transfer of monitors and infusions should follow
Transport to ICU

84. • Most patients require mechanical ventilation for 2-12 hrs, sedation and analgesia
should be continued
• Hypertension unresponsive to sedation and analgesics should be aggressively
treated with vasodilators
• Extubation is considered when patient becomes conscious, muscle paralysis has
worn off, blood gas values are acceptable, surgical hemostasis is adequate and the
patient is hemodynamically stable
Care in ICU

85. CABG procedures relieve chest pain and angina, enable patients to resume a
healthy life style, lower the risk of further heart attack and its consequences
They do not prevent coronary disease from recurring, hence medications
along with appropriate lifestyle changes are strongly recommended to reduce
the risk of recurrence

86. THANK YOU