anaesthetic implications in a patient with poor lv function by dr sanjula virmani

8/11/2019 Anaesthetic Implications in a Patient With Poor LV Function by Dr Sanjula Virmani

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Anaesthetic implications in a patient

with poor LV function

Dr Sanjula Virmani

ProfessorDepartment of Anaesthesiology and Intensive Care

G B Pant Hospital, New Delhi


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LV function can be defined in terms of

LV systolic function and

LV diastolic function


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Systolic dysfunction

Changes in preload and afterload

(characterized by LV remodeling with an

increase in the size of left ventricle and a

change in LV geometry).

Decrease in myocardial contractility

Increase in heart rate

Increase in diastolic filling pressures


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Diastolic dysfunction

Abnormalities of

Diastolic distensibility

Myocardial relaxation

Ventricular filling

The ventricle's passive elastic properties

Heart rate (which determines how much timeis available for ventricular filling). Thus,impaired diastolic function can be aggravatedby tachycardia.


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Pathogenesis


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Poor LV function

Coronary artery disease

Hypertention

Valvular heart disease Cardiomyopathies


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LV Remodeling Alterations in Myocyte Biology

Excitation contraction coupling

Myosin heavy chain (fetal) gene expression

Beta-adrenergic desensitization

Hypertrophy

Myocytolysis

Cytoskeletal proteins

Myocardial Changes Myocyte loss

Necrosis

Apoptosis

Autophagy

Alterations in extracellular matrix (Matrix degradation Myocardial fibrosis)

Alterations in Left Ventricular Chamber Geometry LV dilation

Increased LV sphericity

LV wall thinning

Mitral valve incompetence


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Left ventricular remodelling (Geometry)


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Determinants of LV function

LVEDP (5-12 mm Hg)

LAP (2-12 mm Hg)

PCWP (4-12 mm Hg)

CVP (1-5 mm Hg)

Calculations and measurements:

CI (25-42 L/min/m2)

SVI (40-60 mL/beat/m2

) SWI (45-60 g.m/m2)

EF


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Determinants of LV function cont.

The most useful parameter in daily practice is

the LVEF fraction.

EF> 50% is considered to be normal

EF between 35 to 50% is moderately

depressed

EF < 35% represents a severely depressedfunction


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Preoperative preparation of the

patient


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If not an emergency

Identify any active cardiac conditions

Identify and stratify the risk involved in the

surgery

Assess the patients functional capacity and

clinical risk factors

Optimise the medical therapy

Consider coronary revascularization


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Assess the patients clinical features Markers of cardiac risk

Patients cardiac status

Order tests only when results may changemanagement

Interventions that may result from specialisedtests include delaying surgery, coronaryrevascularization, medical optimization,additional specialists involvement, modifiedintra-op and post-op monitoring or modifying thesurgical location.

C diti i hi h th ti t h ld d l ti


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Conditions in which the patients should undergo evaluation

and treatment (patient specific factors) as per ACC/AHAA

2007 guidelines categorised as Class I, Level B


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Functional status should be evaluated

Underlying cardiac conditions apparently stable

Stable angina

Distant MI

Prior HF Moderate valvular heart disease

Identify comorbid conditions

DM

Stroke

Renal insufficiency

Pulmonary disease


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Estimated energy requirements for various

activities, based on Duke Activity Status Index

1 MET Can you Take care of yourself

Eat, dress, or use toilet

Walk indoors around the house?

Walk 1 to 2 blocks on level ground at 2-3 mph


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Risk stratifications in patients undergoing noncardiac

surgery (procedure related factors)


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Lees Revised Cardiac Risk Index.

Circulation 1999; 100: 1047Clinical variable Points

High-risk surgery (i.e.,

intraperitoneal , intrathoracic,

or suprainguinal vascular

surgery)

1

CAD 1

CHF 1

History of cerebrovasculardisease

1

Insulin treatment for DM 1

Preop serum creatinine >2.0

mg per DL

1

Risk Class Points Risk of

complications

I. Very low 0 0.4

II. Low 1 0.9

III. Moderate 2 6.6

IV. High 3+ 11


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Noninvasive stress test

To be considered only if the test results have apotential to change patient management

In patients with normal ECG, who are able to

exercise-Exercise ECG testing In patients with abnormal resting ECG-stress

cardiac imaging

In patients who are unable to performadequate exercise-pharmacologic stressimaging


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Coronary Angiography

Unstable coronary syndromes

Stress test is uncertain in high risk patient

undergoing major surgery

Possible indication for coronary

revascularization


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Optimise medical therapy

-blockers

Low dose aspirin

Statins

2 agonists

Calcium channel blockers

Nitrates


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Fleisher LA, et al 2009 ACCF/ AHA focused update on perioperative Beta

Blockade Incorporated Into the ACC/AHA 2007 Guidelines on Perioperative

Cardiovascular Evaluation and Care for Noncardiac Surgery. A Report of the

American College of Cardiology Foundation/ American Heart Association TaskForce on Practice Guidelines. Circulation 2009; 120: 169-276

Continue beta-blocker therapy in patients who

are already receiving these agents for angina, HT,or other ACC/AHA class I indications (Level ofevidence C)

Initiation recommended

in those undergoing vascular surgery who haveischaemia on preoperative testing ( Class IIa)

CAD or high cardiac risk (more than 1 clinical riskfactors undergoing intermediate risk surgery)


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Statins Beneficial effect on systemic atherosclerosis

Improve atherosclerotic plaque stability (antithrombogenic, antiproliferative)

Inhibit leucocyte adhesion

Lipid lowering effect (decrease cholesterol, increase HDL)

Pleiotropic effects

Increase endothelial NO synthetase

Generation of ROS

Decrease endothelin I production

Improve thrombogenic profile

Decrease inflammation

Decrease CRP levels

Inhibition of atherosclerosis


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Fleisher et al. ACC/AHA 2007 perioperative

guidelines. J Am Coll Cardiol 2007; 17: 206

Statins should be continued in patients

currently taking statins. Class I (level of

evidence B)

Statin use is reasonable in patients undergoing

vascular surgery with or without clinical risk

factors. Class IIa (Level of evidence B)


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Alpha 2 agonists for perioperative control of

HT maybe considered for patients with knownCAD or at least 1 clinical risk factor. Class IIIb

(Level of Evidence B)


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Nitroglycerin : As a prophylactic agent to

prevent MI its usefulness is unclear and the

recommendation for its prophylactic use must

take into account the anaethetic plan andpatient haemodynamics as well as recognise

that vasodilation and hypovolaemia can occur.

Class IIIb (Level of evidence C)


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Other previously prescribed medication shouldcontinue in the perioperative period

Aspirin

Medication for HT, CHF, arrhythmias

A combination of -blockers, low dose aspirin and statinsis most promising

Devereaux et al. How strong is the evidence for the use ofperioperaative beta blockers in non-cardiac surgery? Systematic

review and meta-analysis of randomised controlled trials. BMJ

2005; 331: 313-21


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Limited role for coronary

revascularization and benefit

apparently limited to left main disease

Revascularization failed to affect any outcomemeasure, including mortality or the development of MI

out to 6 years of follow up (CARP Study)Mc Falls EO, et al. Coronary-artery revascularization before elective

major vascular surgery. N Engl J Med 2004; 351: 2795-2804

Poldermans D et al. A clinical randomized trial to evaluate

the safety of a noninvasive approach in high riskpatients undergoing major vascular surgery: the

DECREASE-V Pilot study. J Am Coll Cardiol 2007; 49:

1763-1769


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Management of patients with prior PCI


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h d


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Anaesthetic considerations

blocker dose titrated to achieve a target HR of 60bpm

Continue aspirin, statin and when indicated ACE

inhibitor Anaemia promptly identified and treated

ECG-baseline, immediately after surgery and on first 2days after surgery

Creatinine kinase-MB and troponin-after surgery andon the following day

Inotropes which increase myocardial oxygen demandshould be avoided

Perioperatively pain well controlled

Maintenance of body temperature in a normothermicrange

Intraoperative and postoperative surveillance formyocardial ischaemia and infarction, arrhythmias and

venous thrombosis


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Anaesthetic considerations cont.

PAC

PAC insertion is reasonable in patients at risk

for major haemodynamic disturbances. The

decision to insert must be based on patients

disease, surgical procedure and practice or

experience in the use of PAC. Class IIb (Level of

Evidence B)


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IABP

Documented use in unstable coronary

syndromes and severe CAD undergoing urgent

non cardiac surgery

Use is associated with complications

Currently there is insufficient evidence to

determine the benefits vs. risks of

prophylactic placement


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No study has clearly demonstrated a change in

outcome from the routine use of PAC, ST-

segment monitor, TEE

The choice of anaesthetic technique and

intraoperative monitors is best left to the

discretion of the anaesthesia care team.


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Postoperative management

Surveillance for: Myocardial ischaemia

Arrhythmias and conduction disorders

Haemodynamic monitoring to continue

Postoperative pain management Patient controlled analgesia techniques are associated

with greater patient satisfaction and lower pain scores

Epidural or spinal opiates

The care team should take responsibility for longterm care of the patient by way of routineprophylactic medical therapy/diagnostic testing.


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anaesthetic implications in a patient with poor lv function by dr sanjula virmani

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