ANESTHESIA FOR OFF PUMP BYPASS SURGERIES

1. ANESTHESIA FOR OFF PUMP
CORONARY ARTERY BYPASS
GRAFTING (OPCAB)
DR GEETANJALI S VERMA
REGISTRAR (CARDIAC ANESTHESIA)
MANIPAL HOSPITAL, BLORE

2. DEFINITION
• Off-pump coronary artery bypass or "beating heart"
surgery is a form of CABG surgery performed
without CPB (heart-lung machine) as a treatment
for coronary heart disease.
• During most bypass surgeries, the heart is stopped and a
heart-lung machine takes over the work of the heart and
lungs.
• When a cardiac surgeon chooses to perform the CABG
procedure off-pump, also known as OPCAB (Off-pump
Coronary Artery Bypass), the heart is still beating while
the graft attachments are made to bypass a blockage.
DR GEETANJALI S VERMA

3. THE BEGINNING
• First open heart surgery - performed by John Gibbon in
1952 using cardiopulmonary bypass
• First successful OPCAB was performed in 1961 and
Kolesov in 1964 performed the first successful
anastomosis of left internal mammary artery (LIMA) to
left anterior descending artery (LAD)
• In 1967, Favalaro and Effler performed reversed
saphenous vein grafting.
• In 1968, Green performed anastomosis of the internal
mammary artery to the coronary artery .
DR GEETANJALI S VERMA

4. Development of modern epicardial
stabilizers
• In early reports, compressive devices (e.g., metal
extensions rigidly attached to the sternal retractor) were
used to reduce the motion of the coronary vessel during
the cardiac and respiratory cycles. These devices often
interfered with cardiac function and were impossible to use
for left circumflex coronary artery lesions.
• Modern devices typically apply gentle pressure or
epicardial suction, reducing the effect on myocardial
function while providing better fixation of the area
immediately surrounding the coronary artery anastomotic
site. These devices also allow greater access to arteries on
the inferior and posterior surfaces of the heart
DR GEETANJALI S VERMA

5. OPCAB tissue stabilization and heart positioning devices.
Verma S et al. Circulation. 2004;109:1206-1211
Copyright © American Heart Association, Inc. All rights reserved.
Genzyme Immobilizer
utilizes a stabilization platform and silastic vessel loops
the Medtronic Octopus4 tissue stabilizer and Starfish2 heart positioner
utilize vacuum suction to stabilize and position the heart.
Coro-Vasc System (CoroNeo Inc)
illustrates silastic snares that are looped around the target coronary vessel
and then fixed to a small immobile plate, thus directly immobilizing the target vessel.

6. PATIENT SELECTION
• a. Early reports of OPCAB often described single-vessel
or double-vessel bypass performed on low-risk
patients - promoted for early recovery and discharge.
• b. OPCAB is now promoted for multivessel bypass in
patients with risk factors for adverse outcomes.
Elderly patients at risk for stroke, patients with severe
lung disease, or patients with severe vascular disease
and/or renal dysfunction are often selected.
• Zenati et al. and others have described combining
MIDCAB (i.e. IMA to LAD) with angioplasty/stent to
other vessels in high-risk patients.
DR GEETANJALI S VERMA

7. OPCAB Demands
Exposure of post, Lat wall of the heart.
Stabilization of target area.
Visualization Occlusion of the Coronary Ar.
or Shunt.
Stable Hemodynamics.
DR GEETANJALI S VERMA

8. CONTRAINDICATIONS
- Very small arteries ( <1mm)
- Calcified arteries.
- Poor conduits.
- Huge hearts.
- Hemodynamic Instability/Ischemia.
- Cardiogenic shock.
DR GEETANJALI S VERMA

9. GOALS OF ANESTHETIC MGMT
• Provision of safe anaesthesia using a technique that offers
maximum cardiac protection and stability
• Maintaining haemodynamics in the intraoperative period
by physical and pharmacological methods
• Allowing early emergence, ambulation
• Providing adequate pain relief in the postoperative
period.
DR GEETANJALI S VERMA

10. PRE OP ASSESSMENT
• For optimization of diabetes, hypertension, reactive
airway and other coexisting morbidities
• To alley anxiety related to the procedure
• Preoperative assessment of the carotid arteries
• Essential investigations done: CBC, coagulation profile,
lipid profile, electrolytes, Blood grouping and serology,
renal and liver function tests, CXR, ECG, Echo, USG
abdomen (elderly males), PFT
DR GEETANJALI S VERMA

11. PRE MEDICATION
- Anti aspiration prophylaxis: Ranitidine (150mg) /
Pantoprazole (40mg) + prokinetic (Metochlopramide 10 mg)
- Anti anxiety: tab Alprazolam 0.5-1mg oral
- 0.05mg.kg -1 of midazolam + 1µg.kg -1 of fentanyl IV
30minutes prior to surgery with supplemental oxygen.
- Regular medn:
- Beta blockers should be continued in same dosage
- Anti platelet medications - stopped atleast 1 week prior to
surgery
- ACE inhibitors may be stopped 24 to 36 hours prior to
surgery (substituted with calcium channel blockers)
- For DM patients – conversion to short acting Insulin
DR GEETANJALI S VERMA

12. INTRA OP MONITORING
- ECG – lead II and V5
- well visualized 'P' wave and QRS complex prior to commencing
the surgery
- SpO2, ETCO2
- Temperature monitoring
- Urinary output monitoring
- Invasive blood pressure (IBP) monitoring - By radial or
femoral artery
- The cannulation of the femoral artery not only permits access to
the central arterial tree but provides access to quick insertion of
an intra aortic balloon pump.
- If radial artery cannulation is planned the Allen's test must be
performed prior to performing cannulation.
DR GEETANJALI S VERMA

13. Pulmonary artery catheter (PAC)
Usually placed via the right internal jugular vein.
Indications:
 Ejection fraction <0.4
 Significant abnormality of the left ventricular wall
motion.
 LVEDP > 18 mm Hg at rest.
 Recent MI and unstable angina.
DR GEETANJALI S VERMA

14. Transesophageal echocardiography
(TEE)
Advantages:
- Identify myocardial ischaemia early by detecting regional wall motion
abnormalities.
- Assess left ventricular dysfunction intra operatively.
- Assessing the improvement in myocardial function after the completion of
revascularization.
Disadvantage
Inability to image the required part of the heart during grafting .
DR GEETANJALI S VERMA

15. INDUCTION
• Induction should be slow
• By intravenous (Propofol/ Etomidate/ Thiopentone + Opioids
(fentanyl / morphine) +BZD) or inhalational method (Sevo/Iso in 1-
2 MAC)
• Neuromuscular blockade - 0.7 mg/kg Rocuronium IV or
Vecuronium 0.08-0.1 mg/kg IV (Pan/atrac – tachy)
MAINTENANCE
• Infusion of fentanyl, atracurium +/- Midazolam
• Isoflurane / O2/ air
DR GEETANJALI S VERMA

16. INTRAOP PROBLEMS
1. HYPOTENSION
– treated with volume loading
– Maintain adequate heart rate in sinus rhythm.
– increasing afterload to maintain systemic perfusion
pressures.
– Inotrope therapy - dopamine, epinephrine, dobutamine
infusion.
– Phenylephrine
– Inform surgeon - cotton packs can be placed under the
heart and the epicardial stabilizers should be repositioned.
– resting the heart in the pericardial cavity.
– If there is no improvement, an intra aortic balloon pump
support can be instituted.DR GEETANJALI S VERMA

17. 2. ARRYTHYMIAS
- Rule out causes: MI, electrolyte imbalance, hypothermia
- Use lidocaine (without preservative) infusion if patient has
arrhythmia caused by myocardial ischaemia.
- Electrolyte imbalance - potassium chloride, magnesium
sulfate, calcium, bicarbonate – as suggested by ABG
- Temperature correction
DR GEETANJALI S VERMA

18. 3. HEPARINIZATION
- Dose of heparin is 2mg.kg -1 (200 units.kg -1 )
intravenously.
- ACT performed 3 minutes after administration.
- The goal is to keep the ACT between 250 - 300 seconds.
- ACT repeated hourly and repeat bolus of 5000 units
Heparin is essential if ACT <250 seconds.
- Heparin is reversed with protamine sulfate (1 mg/1mg of
heparin. )
- Acceptable ACT – upto 140 seconds after protamine
administration.
- A high ACT will require additional protamine in a dose of
25 to 50 mg.
DR GEETANJALI S VERMA

19. 4. HYPOTHERMIA
- Warm blanket covers
- OT room temp
- The time taken for sterile preparation by painting and
draping by sterile sheets should be kept to the minimum.
- Warm IV fluids
- Low fresh gas flows
DR GEETANJALI S VERMA

20. 5. MYOCARDIAL ISCHEMIA
- PREVENTION
- Maintaining systemic blood pressure (+/- 10%), keeping
MAP of at least 70 mm Hg at all times
- Reduction in myocardial oxygen consumption by
avoiding tachycardia using intra operative beta-blockers
or calcium channel blockers.
- Ischaemia during distal anastomosis can be prevented
by using intraluminal coronary shunts .
DR GEETANJALI S VERMA

21. Intracoronary
shunts
These are double
limb shunts that fit
into the proximal
and distal ends of
the open coronary
artery
DR GEETANJALI S VERMA

22. Intracoronary shunts
Benefits:-
 Native coronary arterial blood flow is maintained
preventing intraoperative ischaemia.
 Blood loss during coronary anastomosis is avoided or
decreased.
 Prevents embolization of CO2 into the coronary arteries.
 Prevents the surgeon from taking a suture on the posterior
wall of the coronary artery.
 Assures proper coronary anastomosis.
 Can reverse changes caused by ischaemia (like
myocardial oedema, endothelial and contractile
dysfunction)
DR GEETANJALI S VERMA

23. OPCAB technology in use.
Verma S et al. Circulation. 2004;109:1206-1211
Copyright © American Heart Association, Inc. All rights reserved.

24. 6. Haemodynamic changes related to
heart position
 Lifting and rotating the heart during OPCAB can alter the
haemodynamics such as cardiac output, stroke work, left
ventricular end diastolic pressure and right atrial pressure.
 During grafting of right coronary artery, bradycardia can
occure due to reduction in blood supply to the sinus and AV
nodes, so if required use atropine and atrial pacing
 During grafting of the right coronary artery and obtuse
marginal branches "verticalization" of the heart is required, so
posterior pericardial stitches and a gentle retracting socket will
greatly facilitate haemodynamics
 Reduction in the dose of intravenous vasodilators can increase
the haemodynamic changes. During such times it may be
essential to reduce the dose of the vasodilator and add a
vasoconstrictor.
DR GEETANJALI S VERMA

25. POST OP MGMT
• MONITORING
• 5 lead ECG monitoring - for any fresh changes like
ischaemia or myocardial infarction - treated with LMWH,
anti platelet medications, insertion of an intra aortic
balloon pump or revision of grafting.
• SpO2, ETCO2, IBP, Temp., ABG
• Always carry prefilled syringes of diluted 1:200,000
adrenaline, 1.2mg of atropine and 100mg of lidocaine
(preservative free) to treat a crisis during the transfer
phase.
DR GEETANJALI S VERMA

26. POST OP PAIN MGMT
• Epidural analgesia: epidural fentanyl infusion
with Fentanyl 3000 mcg (60 ml), 0.5% bupivacaine 55ml
and saline 155ml are added to make a final total volume
265 ml & start at a rate of 2ml.hour -1
• Intravenous opioids: Fentanyl 3000mcg and saline
215ml are added to make a final concentration 11
mcg.ml -1 of fentanyl.
DR GEETANJALI S VERMA

27. ICU MGMT
VENTILATION
FiO2 of 0.8
• Vt 6-10 ml/kg
• RR: 12- 15/min
• I:E ratio of 1:2
• controlled mode of ventilation.
• ABG performed after thirty minutes.
• FiO2 is reduced to 0.4 if oxygenation, carbon dioxide
elimination and tissue perfusion maintained
DR GEETANJALI S VERMA

28.  Thirty minutes later, assessment of foll done:
 blood loss (not more than 10% of blood volume)
 fluid balance (not more than 10-15 ml.kg- 1 body weight)
 core temperature ( not less than 35 deg Celsius ),
 arrhythmias
 urine output (at least 1-2 ml.kg -1 .hr -1 )
If the residual neuromuscular blockade is present then reversed
by injecting a combination of neostigmine and glycopyrrolate.
 After confirming adequacy of reversal ventilatory mode is
switched to the spontaneous modes of ventilation, such as
pressure support, or continuous positive airway pressure.
 Thirty minutes after supported ventilation, ABG analysis is
repeated and if the analysis shows satisfactory values of
oxygenation, carbon dioxide elimination and metabolism, the
patients are extubated.
DR GEETANJALI S VERMA

29. FAST TRACK ANESTHESIA
• Defined as tracheal extubation within 8 hours after
cardiac surgery, early mobilization of patient and early
discharge from the hospital.
• Use of short acting opioid medications
• Long acting sedatives should be avoided
• Early extubation resulted in regaining the cough reflex
and thus a lower incidence of atelectasis and pneumonia.
• Patients not suitable - bleeding, dysrryhtmias and
haemodynamic instability
DR GEETANJALI S VERMA

30. COMPARING ON AND OFF PUMP CABG
1. Systemic inflammatory response syndrome (SIRS) -A
combination of non pulsatile flow, myocardial ischaemia,
hypothermia and contact of the patient blood with the
artificial surface of the extra corporeal circuit is responsible
for the inflammatory process.
2. Coagulopathy-disruption of the coagulation system and
haemodilution after cardiopulmonary bypass is avoided in
OPCAB
Less blood loss in OPCAB
Ascine – Eur. J. Cardioth. Surg. 1999
Puskas – Ann. Thor. Surg. 1998
DR GEETANJALI S VERMA

31. 3. Neurologic dysfunction- due to embolization,
inflammation, hypoperfusion and hyperthermia.
Type 1 - Death either due to stroke or hypoxic
encephalopathy, stupor & coma. (Risk factors are DM,
atherosclerosis in the proximal aorta and pre existing
impairment of cerebral blood flow)
Type 2 - Intellectual dysfunction - memory deficits,
confusion or agitation - due to small micro emboli and
inadequate perfusion
The incidence of stroke after OPCAB is about 1% when
compared to 9% after ON pump CABG
DR GEETANJALI S VERMA

32. Neurological Outcome
Only few prospective Randomized Trials showed superiority of OPCAB Vs CABG.
1. Sedrakan - Stroke 2006
41 randomized trials – 50% reduction of stoke in OPCAB
2. Glenville – Ann. Thor. Surg. 2004
Elderly P. Stroke CABG – 3% OPCAB 1%
3. Mohr – Ann. Thor. Surg. 2003
16,184 p. Stroke CABG - 3.8% OPCAB 1.9%
Others
1. Alamanni – Eur. J. Cardioth. Surg. 2007
No difference stroke rate
2. Lund – Ann. Thorac. Surg. 2005
No difference in long term cognitive function or MRI evidence of brain injury
On the Other Hand
Puskas – Ann. Thor. Surg. 2000
In series of 10,800 p. found 3 independent variables for prediction of stroke –
age, previous Tia, carotid bruit
DR GEETANJALI S VERMA

33. 4. MYOCARDIAL INJURY as assessed by biochemical
markers is much less after OPCAB when compared to
CABG. Rastan – Eur. J Cardioth. Surg. 2005
5. PULMONARY DYSFUNCTION caused by
atelectasis, inflammation, increased shunting and
volume infusion. Reddy. Eur. J. Cardthor. Surg. 2006
6. RENAL DYSFUNCTION - lower in patients
undergoing OPCAB.
DR GEETANJALI S VERMA

34. An example of outcome between CABG Vs. OPCAB is
presented in study of “Care Registry”
CABG OPCAB
No. of patients 654 597
Mean no. of grafts 3.4 +1 2.9+1.2
Op. Mortality 1.7% 1.7%
Stroke 0.9% 0.7%
Reop. for bleeding 2.6% 1.0%
Prolonged Ventilation 10.0% 3.4%
Atrial Fibrillation 23.0% 15.0%
Transfusions needed 51.0% 35.0%
Hospital stay 7.5 d 6.2 d
Mortality 1 y 4.9% 4.6%
Myocardial Infarction 1y 1.0% 0.7%
Need for Re-vascularization 2.8% 4.1%
Ann. Thor. Surg. 2007
DR GEETANJALI S VERMA

35. Innovations in OPCAB
- Possible to operate in patients with neoplastic
comorbidities.
(Decrease in: inflammatory response, coagulopathy disorders, immunity response and spreading of
malignancy).
- Possiblity to perform in SEMI awake patient CABG
(Br. J. Anaesth. (2008) 100 (2): 184-189.)
- Hybrid Re-vascularization
(defined by the performance of coronary bypass surgery and coronary stenting during the same operation.)
DR GEETANJALI S VERMA

36. OPCAB in a patient with extensive aortic and carotid artery atherosclerotic calcification,
analogous to our case presentation.
Verma S et al. Circulation. 2004;109:1206-1211
Copyright © American Heart Association, Inc. All rights reserved.
OPCAB in a patient with extensive aortic and carotid artery
atherosclerotic calcification,
In this patient, complete arterial revascularization was
performed using the OPCAB technology
without aortic manipulation, cannulation, or proximal
anastomosis.
The left internal thoracic artery (LITA) was anastomosed to
the LAD,
with a free radial T graft from the LITA anastomosed to both
the second obtuse marginal and posterior descending
branches.
An angiogram showing a radial T graft appears to the right.

37. RELATED ARTICLES
• Chakravarthy MR, Prabhakumar D. Anaesthesia for off pump coronary
artery bypass grafting - the current concepts. Indian J Anaesth 2007
;51:334. http://www.ijaweb.org/text.asp?2007/51/4/334/61162
• Frank W. Sellke, MD, Co-Chair; J. Michael DiMaio, MD. Comparing On-
Pump and Off-Pump Coronary Artery Bypass Grafting. Circulation. 2005;
111: 2858-2864
• Does off-pump coronary artery bypass (OPCAB) surgery improve the
outcome in high-risk patients?: a comparative study of 1398 high-risk
patients. Eur J Cardiothorac Surg (2003) 23 (1): 50-55. doi: 10.1016/S1010-
7940(02)00654-1
• Diastolic dysfunction and off-pump coronary artery bypass. Br. J. Anaesth.
(2009) 102 (6): 887-888. doi: 10.1093/bja/aep118
• Haemodynamic changes in OPCAB procedures regarding different
coronary artery anastomoses. European Journal of Anaesthesiology: July
2001 - Volume 18 - Issue - p 25–26
DR GEETANJALI S VERMA

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