Anaesthesia in Cardiac Patients for Non-cardiac Surgeries Dr. Rashad Siddiqi

Learning Objectives

After this lecture, you should be able to:

�  identify factors which will lead to increased cardiovascular risk for patients undergoing non-cardiac surgery

�  decide which patients require further cardiovascular testing

�  make optimization plan for such patients

�  understand the principles of anaesthesia for patients with cardiac disease

Introduction

�  increasing number of cardiac patients for non-cardiac surgery

•  about 33% at risk of cardiovascular disease

•  not diagnosed / quantified in many

�  challenging •  cardiac lesions will still exist after the surgery

(unlike patients undergoing cardiac surgery)

•  high perioperative cardiac morbidity (MI, arrhythmias)

•  peri-op MI has mortality 40 to 70%

•  cardiac complications <-> non-cardiac complications

Pre-operative Assessment

Pre-operative Assessment

Assess risk

Order relevant

tests Optimize patient

Formulate plan

Inform patient

Assessing the Risk

Assessment of Risk

�  Cardiac Risk Index - Goldman et al 1977

�  modified by Detsky in 1986

�  multi-factorial risk analysis

�  combines clinical & investigative parameters

�  patients grouped into 4 risk categories (for major complications or cardiac death)

Gol

dman

Car

diac

ris

k In

dex

Assessment of Risk

�  Revised Cardiac Risk Index (RCRI) - TH Lee 1999 �  One point each for each of the following:

•  High-risk surgical procedures

•  History of IHD

•  History of CHF

•  History of cerebrovascular disease

•  Pre-op treatment with insulin •  Pre-op serum creatinine > 2.0 mg/dL

�  Risk o  0.4% at score 0 o  0.9% at score 1

o  6.6% at score 2

o  11% and score 3 or more

Assessment of Risk

�  2014 ACC/AHA updated guidelines

�  Based on American College of National Surgical Quality Improvement Program (NSQIP) Myocardial Infarction and Cardiac Arrest (MICA) and American College of Surgeons NSQIP Surgical Risk Calculator

Gupta et al. Development and validation of a risk calculator for prediction of cardiac risk after surgery. Circulation. 2011;124: 381–7

NSQ

IP S

urgi

cal R

isk

Cal

cula

tor

Coronary Artery Disease

�  MACE after non-cardiac surgery associated with prior CAD events

Patie

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Fact

ors

33%

14%

19%

12% 8%

11%

6%

10%

0%

10%

20%

30%

40%

Post-op MI 30-day mortality

0-30 days 31-60 days 61-90 days 91-180 days

Coronary Artery Disease

�  risk modified by the presence and type of coronary revascularization (CABG vs PCI) at the time of MI

�  ≥60 days should elapse after MI before non-cardiac surgery in the absence of a coronary intervention

�  recent MI (<6 months) an independent risk factor for peri-op stroke

�  8-fold increase in the peri-op mortality

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isk

Fact

ors

Livhits M et al. J Am Coll Surg. 2011;212:1018–26

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Fact

ors

CLASS I

�  Elective non-cardiac surgery should be delayed o  14 days after balloon angioplasty

o  30 days after BMS implantation

o  365 days after DES implantation

CLASS IIb

�  Elective non-cardiac surgery after DES

o  may be considered after 180 days if the risk of further delay is high

Coronary Revascularization

Heart Failure

�  survival after surgery for those with a LVEF ≤29% is significantly worse than for those with a LVEF ≥29%

�  HF + preserved LVEF -> lower all-cause mortality

�  HF + reduced LVEF -> higher all-cause mortality •  high risk of death with LVEF <40%

�  Diastolic dysfunction ± systolic dysfunction

•  higher rate of MACE

•  prolonged length of stay

•  higher rates of post-op HF

Patie

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isk

Fact

ors

Valvular Heart Disease

�  clinically suspected moderate or greater degrees of valvular stenosis or regurgitation should undergo pre-op echo if

�  no prior echo < 1 year

�  significant change in clinical status

�  valvular intervention before elective non-cardiac surgery is effective in reducing peri-op risk

Patie

nt R

isk

Fact

ors

Arrhythmias

�  peri-op arrhythmias common

�  identified as independent risk factor by Goldman et al

o  subsequent studies indicated a lower level of risk

�  every pre-op arrhythmia should be investigated:

o  underlying cardiopulmonary disease

o  ongoing myocardial ischemia or MI

o  drug toxicity

o  metabolic derangements

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Fact

ors

Diabetes Mellitus

�  high incidence of silent ischaemia

�  ETT is less reliable - lack of angina with exercise

�  dyspnoea - more important symptom

�  é risks in IDDM

Patie

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isk

Fact

ors

Hypertension

�  inclusion as risk factor remains controversial

�  severe LVH associated with sub-endocardial ischemia

�  severe hypertension should be controlled before surgery if possible

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Fact

ors

Renal Impairment

�  pre-op creatinine >180 mmol/l (2 mg/dl)

�  reduced creatinine clearance

�  significant, independent risk factor for postoperative renal dysfunction and cardiac complications

Patie

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Fact

ors

Functional Capacity

�  exercise tolerance assessed by history

�  expressed as metabolic equivalents (MET)

�  1 MET = 3.5 ml O2/Kg/min

�  moderate or excellent functional capacity and low clinical predictors of risk do not need further cardiac investigation

Patie

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Fact

ors

Functional Status

vascular surgical patients and therefore might not be representa-tive of most patients having non-cardiac surgery.

Patient risk factorsPrevious coronary revascularization: patients who haveundergone coronary artery bypass grafting (CABG) or percuta-neous transluminal coronary angioplasty (PTCA) with or withoutstent insertion in the previous 5 years, and who have had norecurrence of symptoms with a return to an active lifestyle, donot need further testing. Elective non-cardiac surgery, in whichthe antiplatelet drugs required to prevent in-stent stenosis mightneed to be discontinued to prevent bleeding, is not recommendedwithin 4e6 weeks of bare-metal stent implantation or within 12months of drug-eluting stent implantation. The presence ofantiplatelet drugs, especially some of the newer ones, mayprovide a challenge to prevention of blood loss. A cardiologist’sopinion on the optimal time to schedule elective surgery and thusdiscontinuation of the antiplatelet agents should be sought.

Previous coronary evaluation: those who have had cardiacevaluation in the previous 2 years should need no furtherinvestigation providing their symptoms have not changed andtheir activity levels have not deteriorated.

Myocardial infarction and ischaemia e advances in thetreatment of myocardial infarction (thrombolysis, PTCA with orwithout stent) have meant that the traditional high-risk period of6 months following infarction may be reduced, providing there isevidence that no further myocardium is at risk. This is assessedby stress testing (discussed below). The heart takes 4e6 weeks toremodel and heal following infarction, during which time it ismore vulnerable to arrhythmias and myocardial stunning. Thehaemodynamic stresses and hypercoagulability associated withsurgery can also lead to extension of the infarct. Patients whohave unstable or severe angina [Canadian Cardiovascular Society(CCS) class III or IV] also have a high probability of continuingplaque rupture and thrombosis. Although it is common practice topostpone truly elective surgery until 6 months after a myocardialinfarction, patients who have had a myocardial infarction over 6weeks previously and show no evidence that further myocardiumis at risk can proceed with urgent surgery with perioperativecardiac risk-reduction strategies. When at least 6 months haveelapsed, those who have resumed normal daily activity and haveno post-infarction angina should not need further testing, unlessthe risk of surgery or the functional capacity warrants it.

Arrhythmias e the cause should be identified and treatmentbegun, especially for arrhythmias that are symptomatic andcause hypotension. Indications for antiarrhythmic drugs andcardiac pacing are the same as in the non-surgical patient.

Decompensated congestive heart failure e these patientsshould have their medical therapy optimized to minimize the riskof worsening their pulmonary oedema. If ischaemia is the cause,they are also at risk of developing a perioperative myocardialinfarction.

Compensated congestive heart failure e patients with a leftventricular ejection fraction less than 35% are at particular riskof perioperative complications.

Diabetes mellitus e there is a high incidence of silentischaemia associated with diabetic neuropathy, making the lackof angina with exercise a less reliable symptom. Dyspnoea,especially with minimal exertion, can be a more importantsymptom. There is only proof of increased risks in those patientson insulin.

Clinical predictors for increased perioperativecardiac risk

Active cardiac conditions (major risk factors)C Unstable coronary syndromes

! Unstable or severe angina (CCS class III or IV)

! Recent myocardial infarction (<30 days)C Decompensated heart failure (NYHA class IV; worsening or

new-onset heart failure)C Significant arrhythmias (including atrioventricular heart

blocks, symptomatic ventricular arrhythmias, supraven-

tricular arrhythmias with uncontrolled ventricular rate,

symptomatic bradycardia, newly recognized ventricular

tachycardia)C Severe valvular disease

! Severe aortic stenosis (mean pressure gradient >40

mmHg; aortic valve area <1 cm2; symptomatic)

! Symptomatic mitral stenosis

Intermediate factors (from the Revised Cardiac Risk Index)C History of ischaemic heart diseaseC History of compensated or previous heart failureC History of cerebrovascular diseaseC Diabetes mellitusC Renal insufficiency

Minor factorsC Age (physiological) >70 yearsC Abnormal ECG (left ventricular hypertrophy, left bundle-

branch block, ST abnormalities)C Rhythm other than sinus (e.g. atrial fibrillation)C Uncontrolled systemic hypertension

CCS, Canadian Cardiovascular Society; ECG, electrocardiography;

NYHA, New York Heart Association.

Box 1

Estimated energy requirements for various activities

Poor functional capacity (1e4 MET)C Light houseworkC Shower or dress without stoppingC Walk at 2e3 mph on level ground

Moderate functional capacity (5e7 MET)C Climb a flight of stairs without stoppingC Walk briskly (>4 mph) on flatC Light gardening

Excellent functional capacity (>7 MET)C Digging in gardenC Carrying shopping upstairsC More strenuous sports (e.g. cycling uphill, jogging)

MET, metabolic equivalents.

Box 2

CARDIAC ANAESTHESIA

ANAESTHESIA AND INTENSIVE CARE MEDICINE 13:10 520 ! 2012 Published by Elsevier Ltd.

Duke Activity Index

Type of Surgery

�  type of surgery -> degree of haemodynamic stress

�  Surgery can be allocated to one of the following cardiac risk categories:

o  vascular (>5%): aortic and peripheral vascular surgery, procedures with large fluid shifts

o  intermediate (1 - 5%): intra-peritoneal, intra-thoracic, head and neck, orthopaedic, prostate surgery and carotid endarterectomy

o  low (<1%): superficial and endoscopic procedures, breast and cataract surgery

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Peri-o

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for

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Dis

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available evidence and expert opinion, the rationale ofwhich is outlined throughout the CPG. The algorithmincorporates the perspectives of clinicians caring for thepatient to provide informed consent and help guideperioperative management to minimize risk. It is alsocrucial to incorporate the patient’s perspective withregard to the assessment of the risk of surgery or

alternative therapy and the risk of any GDMT or coro-nary and valvular interventions before noncardiac sur-gery. Patients may elect to forgo a surgical interventionif the risk of perioperative morbidity and mortality isextremely high; soliciting this information from thepatient before surgery is a key part of shared decisionmaking.

FIGURE 1 Stepwise Approach to Perioperative Cardiac Assessment for CAD

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Pre-operative Cardiac Testing

12 Lead ECG

Pre-operative Resting ECG �  reasonable in patients with Hx of (Class IIa)

�  CAD

�  significant arrhythmia

�  peripheral arterial disesse

�  cerebro-vascular disease

�  structural heart disease

�  may be considered in patients for high-risk surgery without known CAD (Class IIb)

�  routine not useful in patients for low-risk surgical procedures (Class III) S

uppl

emen

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re-o

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sts

Ambulatory ECG

�  used to assess silent ischaemia

�  in many (up to 50%) patients resting ECG abnormalities (e.g. bundle-branch block) make the interpretation difficult

Sup

plem

enta

l Pre

-op

Test

s

Echo (for LV Functions)

�  Echo & Tc99 scanning for myocardial function

�  Echo for nature & severity of valvular heart disease

Sup

plem

enta

l Pre

-op

Test

s

ETT / MPI �  elucidate the possibility of threatened myocardium and

the maximal tolerated HR

Sup

plem

enta

l Pre

-op

Test

s

Surgical Risk

Functional Capacity

ETT / MPI Recommendation

high excellent No IIa

high moderate to good No IIb

high unknown ETT IIb

high poor or unknown ETT + MPI IIb

low routinely No III (No Benefit)

Coronary Angiography

�  Routine pre-op coronary angiography is not recommended (Class III)

�  indications same as for those patients not having surgery

�  CT Angio

o  limited data

o  no value in decision

Sup

plem

enta

l Pre

-op

Test

s

Optimizing the Patient

Pre-

oper

ativ

e Th

erap

y �  revascularization before non-cardiac surgery is recommended in circumstances in which revascularization is indicated (Class I)

�  routine coronary revascularization be performed before non-cardiac surgery exclusively to reduce perioperative cardiac events (Class III)

Coronary Revascularization

Pre-

oper

ativ

e Th

erap

y Class I

�  Continue beta blockers in patients who are on beta blockers chronically

Class IIa

�  Guide management of beta blockers after surgery by clinical circumstances

Class IIb

�  Beta blockers may be started in �  patients with intermediate- or high-risk preoperative tests

�  patients with >3 RCRI factors

�  starting beta blockers to reduce peri-op risk uncertain benefit

�  reasonable to begin preferably >1 d before surgery

Class III (harmful)

�  Beta-blocker therapy should not be started on the day of surgery

Beta-blockers

Pre-

oper

ativ

e Th

erap

y CLASS III (No Benefit)

�  Alpha-2 agonists for prevention of cardiac events are not recommended in patients who are undergoing non-cardiac surgery

alpha-2 agonist

Pre-

oper

ativ

e Th

erap

y �  cause transient intra-op hypotension

�  no change in MACE (death, MI, stroke, kidney failure)

�  ACEI + aspirin + beta blockers + statin -> better 30-day & 12-month risk reduction for MI, stroke, and death

�  no harm in with holding ACEI & ARBs before surgery

�  Recommendation:

�  Continuation of ACEI or ARBs peri-operatively is reasonable (Class IIa)

�  If ACE with held before surgery, it is reasonable to restart as soon as clinically feasible post-operatively

ACE Inhibitors

Pre-

oper

ativ

e Th

erap

y �  Calcium channel blockers

o  significantly reduced ischemia and SVT

o  associated with trends toward reduced death and MI

�  majority attributable to diltiazem

�  dihydropyridines & verapamil do not decrease incidence of MI

�  verapamil decreases the incidence of SVT

�  may precipitate or worsen HF in patients with depressed EF & clinical HF

CCBs

Pre-

oper

ativ

e Th

erap

y �  Recommendations

�  Statins should be continued in patients currently taking statins and scheduled for non-cardiac (Class I)

�  Perioperative initiation of statin use is reasonable in patients undergoing vascular surgery (Class IIa)

�  Perioperative initiation of statins may be considered in patients with clinical indications according to GDMT who are undergoing elevated-risk procedures (Class IIb)

Statins

Pre-

oper

ativ

e Th

erap

y �  consensus among treating clinicians for antiplatelet therapy (Class IIa)

�  elective non-cardiac surgery should not be performed

�  where DAPT needs to be discontinued

o  within 30 days after BMS implantation

o  within 12 months after DES implantation

�  where aspirin needs to be discontinued

o  within 14 days of balloon angioplasty

Anti-platelets

antiplatelet agents addressed in Section 6.2.6. Factor Xainhibitors and direct thrombin inhibitors are examples ofalternative anticoagulants now available for oral admin-istration. Vitamin K antagonists (warfarin) are prescribedfor stroke prevention in patients with AF, for preventionof thrombotic and thromboembolic complications in pa-tients with prosthetic valves, and in patients requiring

deep venous thrombosis prophylaxis and treatment.Factor Xa inhibitors are prescribed for prevention ofstroke in the management of AF. Factor Xa inhibitors arenot recommended for long-term anticoagulation ofprosthetic valves because of an increased risk of throm-bosis when compared with warfarin. The role of antico-agulants other than platelet inhibitors in the secondary

FIGURE 2 Algorithm for Antiplatelet Management in Patients With PCI and Noncardiac Surgery

Colors correspond to the Classes of Recommendations in Table 1. *Assuming patient is currently on DAPT. ASA indicates aspirin; ASAP, as soon as possible;BMS, bare-metal stent; DAPT, dual antiplatelet therapy; DES, drug-eluting stent; and PCI, percutaneous coronary intervention.

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Ant

i-pl

atel

et in

PCI

Patie

nts

Pre-

oper

ativ

e Th

erap

y �  case-to-case basis

�  risks of bleeding vs benefit of anticoagulants �  e.g., anti-coagulants may continue pre-op before

cataract surgery or minor dermatologic procedures

�  bridging anticoagulation (LMWH) � mechanical mitral valve

� mechanical aortic valve and >1 additional risk factor � AF

� previous thromboembolism

� LV dysfunction

� hyper-coagulable condition

� older-generation prosthetic aortic valve

Anti-coagulants

Goal Directed Optimization

�  shown to ê post-op complications & mortality

�  includes

�  preoperative invasive monitoring

�  manipulation of fluid

�  inotropic therapy to optimize cardiac index, O2 delivery & consumption)

�  é pressure on ICU / HDU beds

Intra-operative Management

Principle

�  Maintain O2 supply-demand ratio

�  continue in post-operatively

�  IHD & AS patients

�  Maintenance of BP & reduction of HR

�  Hb ≥ 10 g/dl to optimize the O2 supply

Intr

a-op

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into account, as must the experience and skill of the surgeon andanaesthetist.

Further cardiac investigations: all cardiovascular tests havelimitations and risks and should be carried out only if the resultswill change the patient’s management.

Coronary angiography and revascularization e the indica-tions for these investigations are the same as for those patientsnot having surgery (e.g. unstable angina unresponsive to medicaltreatment, deteriorating severity of symptoms).

Ambulatory ECG monitoring has been used to assess silentischaemia, but in a significant number of patients (up to 50%)resting ECG abnormalities (e.g. bundle-branch block) make theinterpretation difficult.

Stress tests [e.g. exercise ECG, dipyridamole-thallium scin-tigraphy (DTS) or dobutamine stress echocardiography (DSE)]are dynamic investigations that elucidate the possibility ofthreatened myocardium and the maximal tolerated heart rate.DTS and DSE are the only non-invasive tests that improvepreoperative risk stratification.

Echocardiography and technetium-99 scanning assessmyocardial function but cannot predict ischaemic events. Echo-cardiography is also used to assess the nature and severityof valvular heart disease.(For further details of tests, see pages469e474 of this issue.)

Other systems (e.g. respiratory, renal, endocrine, skeletal,airway) need assessment and possible further investigation. Theresults may affect the anaesthetic plan.

Preoperative therapy

The patient’s condition and medication should be optimized.Most cardiac medication should be continued perioperatively.There is evidence that continuation of angiotensin-convertingenzyme inhibitors can increase the incidence of hypotensionand some physicians have recommended withholding them for24 hours preoperatively. Two specific strategies have been sug-gested to reduce postoperative morbidity and mortality.

! Heart rate control: in 2009 the ACCF/AHA produceda Focused Update on Perioperative b-blockade from ananalysis of many studies. It was noted that there wereconflicting results e there was a decreased incidence ofperioperative myocardial infarction, but increased inci-dence of stroke and all-cause mortality. It was recom-mended that patients already taking b-blockers shouldcontinue them until surgery but starting them in theimmediate preoperative period for those who have nocoronary disease or risk factors is not recommended. Theoptimum time from surgery for commencing and dis-continuing b-blocker is less clear and it seems thatachieving a target heart rate is more important.

! Goal-directed optimization (preoperative invasive moni-toring and manipulation of fluid and inotropic therapy tooptimize cardiac index, oxygen delivery and consumption)is less popular now, perhaps due to increased pressure onintensive care unit and high-dependency unit beds. It hasbeen shown to decrease postoperative complications andoverall mortality.

Other studies with a2-agonists are not so convincing. There isinsufficient evidence about the effects of preoperative and

intraoperative nitroglycerine. Treatment with statins has recentlybeen shown to reduce the risk of perioperative events, as it haswith some calcium channel blockers. CABG and PTCA areappropriate only in patients who would require them even if theywere not awaiting surgery. The combined risk of both proceduresmight be greater than that of non-cardiac surgery with peri-operative risk-reduction strategies.

Premedication should be adequate to allay anxiety, andoxygen therapy preoperatively can be advantageous. Warfarintherapy should be replaced with heparin, and antiplatelet drugs(aspirin, clopidogrel) should be stopped at the appropriate time.

Intraoperative management

PrinciplesThe oxygen supplyedemand ratio must be maintained to avoidischaemia (Box 3), and this should be continued into the post-operative period. In coronary artery disease, the pressuregradient across the fixed stenoses is important because thecoronary arteries cannot dilate in response to increased oxygendemand. Maintenance of arterial blood pressure and reduction ofheart rate should reduce the risk of ischaemia. This is alsoimportant in patients with aortic stenosis. It has been suggestedthat, in cardiac patients, a haemoglobin level of 10 g/dl or moreis needed to optimize the oxygen supply.

In the preoperative plan, it is important to decide which valuesof preload, heart rate, systemic vascular resistance, pulmonaryvascular resistance and rhythm are acceptable, and to anticipatethe times when the maintenance of these values will be mostdifficult (e.g. induction, intubation, blood loss). Strategies to dealwith these situations should be considered preoperatively.

Anaesthetic agentsThe choice of anaesthetic agents and techniques does notsignificantly affect the risks of perioperative complications,

Factors affecting myocardial oxygen supply anddemand

SupplyC Coronary perfusion pressure (aortic diastolic pressure

minus left ventricular end-diastolic pressure)C Blood oxygen content

" Partial pressure of oxygen in arterial blood (PaO2)

" Haemoglobin concentration

C Coronary vascular resistance

" Coronary artery stenosis

" Heart rate and left ventricular end-diastolic pressure

" Autoregulation

DemandC Heart rateC ContractilityC Wall tension

" Left ventricular end-diastolic pressure

" Arterial pressure

" Contractility

Box 3

CARDIAC ANAESTHESIA

ANAESTHESIA AND INTENSIVE CARE MEDICINE 13:10 522 ! 2012 Published by Elsevier Ltd.

Anaesthetic Plan In

tra-

op M

anag

emen

t �  important to decide which values of preload, heart rate, systemic vascular resistance, pulmonary vascular resistance and rhythm are acceptable

�  anticipate the times when the maintenance of these values will be most difficult (e.g. induction, intubation, blood loss)

�  make strategies to deal with these situations “pre-operatively”

Choice of Anaesthesia Spinal / Epidural

�  depends on

�  type of surgery

�  patient comorbidities

�  patient preferences

�  post-op myocardial ischemia / MI similar

�  2011 Cochrane review - meta-analysis 4 studies of lower

limb revascularization

�  2001 RCT - abdominal aortic surgery

�  no cardio-protective benefit of neuraxial anaesthesia

Intr

a-op

Man

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Choice of Anaesthesia

General Anaesthesia (Volatile vs TIVA)

�  Use of either a volatile anesthetic agent or total intravenous anesthesia is reasonable for patients undergoing non-cardiac surgery, and the choice is determined by factors other than the prevention of myocardial ischemia and MI (Class IIa)

Intr

a-op

Man

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Anaesthetic Agents In

tra-

op M

anag

emen

t �  Etomidate - fewest cardiovascular effects

�  Thiopentone / propofol - titrate carefully to effect

�  Pretreatment with opioid �  reduces the required dose of induction agent

�  attenuates the haemodynamic response to intubation.

�  Remifentanil - infusion �  haemodynamic stability

�  suppress the stress respons

�  consider other methods for post-op analgesia

�  Isoflurane - ‘coronary steal’ is no more a concern

�  N2O - myocardial depressant

Peri-op Pain Manamgement CLASS IIa

�  Neuraxial anesthesia for postoperative pain relief can be effective in patients undergoing abdominal aortic surgery to decrease the incidence of perioperative MI

CLASS IIb

�  Perioperative epidural analgesia may be considered to decrease the incidence of peri-operative cardiac events in patients with a hip fracture

Intr

a-op

Man

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Intra-op Monitoring In

tra-

op M

anag

emen

t ECG

�  Myocardial ischaemia more easily detected with a 5-lead ECG

�  V5 most sensitive single lead.

�  ST segments analysis in high-risk patients.

�  Invasive monitoring by arterial catheters can be useful in those at high risk, especially if they have had a recent MI with cardiac failure

Intra-op Monitoring TEE

�  used to assess volume status and valvular disease

�  best way to detect ischaemia early (RWMA)

�  emergency use of peri-op TEE is reasonable in hemodynamic instability to determine the cause, when it persists despite attempted corrective therapy (if expertise is readily available) - Class IIa

�  routine use of intra-op TEE to screen for cardiac abnormalities or to monitor for myocardial ischemia – Class III

Intr

a-op

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Intra-op Monitoring PA Catheter

�  most useful in monitoring volume status & cardiac performance, such as o  cardiac output/index

o  mixed venous oxygen saturation

o  SVR / PVR

�  may be considered when underlying medical conditions that significantly affect hemodynamics cannot be corrected before surgery (Class IIb)

�  Heart Failure

�  Severe valvular disease

�  combined shock states

�  Routine use of PA catheterization even in those patients with elevated risk, is not recommended (Class III)

Intr

a-op

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Temp Management �  Hypothermia associated with several perioperative

complications

�  wound infection

�  MACE

�  immune dysfunction

�  coagulopathy -> é blood loss -> transfusion requirements

�  death

�  beneficial effects of hypothermia?

�  1997 study -> forced normothermia -> é MACE

�  2010 RCT -> no increased in MACE with hypothermia

Intr

a-op

Man

agem

ent

Temp Management

�  Maintenance of normothermia may be reasonable

to reduce peri-op cardiac events in patients

undergoing non-cardiac surgery (Class IIb)

Intr

a-op

Man

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ent

Post-operative Management

�  é levels of catecholamines & hypercoagulability

�  Most peri-op infarcts occur in the first 3 days;

�  pre-op plan should include post-op care �  same management goals

�  humidified oxygen, for at least 72 hours after major surgery

�  adequate postoperative analgesia

�  maintain haemoglobin

�  thromboprophylaxis continued

�  cardiac medication should be restarted ASAP

Specific Diseases

Valvular Heart Disease

Stenotic Lesions

�  patients have a low, fixed cardiac output

�  poorly tolerate any changes in rhythm, tachycardia and decrease in preload and vascular resistance

�  Replacement of the valve before non-cardiac surgery might need to be considered in those with severe symptomatic disease, especially aortic stenosis

Valvular Heart Disease

Regurgitant Lesions

�  benefit from �  afterload reduction

�  faster heart rates

�  maintenance of preload

Cardiac Transplant

�  All electrical stimulation in the heart is initiated from the donor SA node

�  resting HR 90-120/min

�  no response to: �  carotid sinus massag

�  changes in body position

�  light anaesthesia

�  hypotension.

�  Maintain adequate preload

�  Drugs that act on autonomic system have no effect on the denervated heart

�  Avoid invasive monitoring when possible �  Maintain strict asepsis

�  Antibiotic prophylaxis

�  Continuee immunosuppressive therapy

Other

�  hypertrophic cardiomyopathy & pulmonary hypertension leads to increased risk of perioperative morbid events.

�  The presence of a pacemaker or ICD requires understanding of the programming, the indication for its insertion, electrical hazards and a management strategy for the peri-op period

Thank You