PRE-OP EVALUATION IN PATIENTS WITH

CVS DS FOR NON- CARDIAC SURGERY.

MODERATOR- DR. DARA SINGH

PRESENTED BY- DR. ANUPAM

PURPOSE OF PRE-OP EVALUATION

To identify the patients at risk for peri-op cardiac complications.

To evaluate the severity of underlying ds and if necessary implement measures to prepare high risk patients for non-cardiac surgery.

To stratify the extent of risk and determine the need for pre-op interventions to minimize the risk of periop cardiac complications .

To take informed consent. Rapport establishment.

HISTORY:- Presence ,severity & reversibility of CAD

1) risk factors

2) active cardiac condition

3) previous MI, prior cardiac evaluation

4) past interventions – CABG,PTCA,PM

5) functional capacity ( NYHA)

6) co-morbid conditions

7) dysrhythmias

In Valvular heart diseases – dyspnoea on minimal exertion, orthopnea, PND, embolic events, arrhythmias.

Medications – history, current medication, effectiveness.

History of any ppt factor. Asthma, epilepsy, drug allergy, egg

allergy, past surgery- type of anesthesia, any event, post op complication.

Loose tooth,denture.

EXAMINATION:- VITALS GPE – pallor, cyanosis, JVP, PE CVS examination- displaced apical impulse,

parasternal heave, thrill, palpable P2, S3 gallop

( LVEDP) , S4 ( decrd compliance/ LVH )

Resp examination – b/l air entry, added sounds, pulmonary edema, pleural effusion.

Abd examination – signs of HF Airway assessment – affected in diabetic

pts.

Peripheral venous access Spine examination Neck movement.

LAB EVALUATION-

CHG – Hb, TLC,DLC, Hct, platelet count FBS LFT,RFT with electrolytes. URINE-routine and microscopy. CULTURES in I/E CXR , ECG ASO titers CRP Coagulation profile

CXR :-

Cardiomegaly Signs of LV dysfxn- incrsd pul vascular

markings, pul edema, pleural effusion Pacemaker, ICD can be seen PAH

ECG- CAD- in old MI ,inverted t-wave, prominent and deep

Q-wave, location dysrythmias Conduction defects Digitalis toxicity-inverted T-waves , downward sloping

of ST segment, narrow QRS complexes, atrial fibrillation, PAT wid 2 degree AV block is pathagnomic of

Chamber enlargement like LVH in hypertensive patients.

Electrolyte imbalance AMBULATORY ECG monitoring-Confirms whether

patients' symptoms are coincident with cardiac arrhythmia, e.g. ventricular ectopic beats or atrial fibrillation ( palpitation)

DETERMINATION OF RISK LEVEL in cardiac patients for non -cardiac surgeries :

Physical status classification(ASA) Cardiac risk index ( Goldman) Revised cardiac risk index ( Lee’s ) Eagle criteria ACC/AHA guidelines 2007

ASA CLASSIFICATION- to assess pts over all physical status 1)normal healthy patient. 2)mild systemic disease not limiting functional

activity 3)severe systemic disease that limits the activity

bt not incapacitating. 4)incapacitating disease that is a constant threat

to life 5)moribund patient who is not going to survive

for >24 hrs with or without operation. 6)brain dead patients. E = emergency procedure.

Cardiac Risk Index History - Age over 70

MI within 5 months Physical - JVP or S3

Significant aortic stenosis EKG - Rhythm other than sinus or PACs

More than 5 PVC/min General - pO2 < 50, pCO2 > 50

K+< 3, bicarb < 20

BUN > 50, Cr > 3 Elevated ALT or chronic liver disease Bedridden from non-cardiac causes Procedure - Emergency

Aortic, Intrathoracic or intraperitoneal

REVISED CARDIAC RISK INDEX6 independent predictors High risk surgery Ischemic heart disease Heart failure Cerebro-vascular disease Pre-op treatment with insulin Pre-op Cr over 2 mg/dl

Rate of major cardiac complications-

0 – 0.5 % 1- 1.3%

2 – 4% >3 – 9 %

ACC/AHA GUIDELINES 2007 Evaluate urgency of surgery Cardiac history and previous evaluation Clinical predictors Functional capacity Surgical risk Tests to determine cardiac risk

PATIENT RELATED CLINICAL PREDICTORS FOR RISK OF PERI-OP CARDIAC COMPLICATIONS-

MAJOR- acute or recent MI, UA, decompensated CCF, significant arrythmias ,severe valvular heart disease.

INTERMEDIATE- mild Angina ,old MI(more thn 1 mnth), insulin dependent diabetes, compensated CCF, pre-op creatinine >2mg%

MINOR- abnormal ECG, cardiac rhythm abnormality, history of stroke, uncontrolled HTN, low functional capacity.

Functional Capacity 1 MET Take care of self Eat, dress, use toilet Walk indoors Walk 1-2 level blocks (2-3 mph) Light housework 4 METs 4 METs Climb flight of stairs or walkup a hill Walk level at 4 mph Run short distance Heavy work Moderate recreation

Strenuous sports >10 METs

Surgical Risk and Mortality

High (>5%) - Emergent major operations, particularly in elderly - Aortic and major vascular procedures - Peripheral vascular procedures - Prolonged procedures with large fluid shifts +/-

blood loss

Intermediate (<5%) - Intraperitoneal / Intrathoracic surgery - Carotid endarterectomy - Head and neck surgery - Orthopedic surgery - Prostate surgery

Low (<1%) - Endoscopic procedures - Superficial procedures - Cataract surgery - Breast surgery

Preoperative Non-Invasive Testing If any 2 factors present: > = 3 Intermediate clinical predictors Poor functional capacity (< 4 METS) High surgical risk

Assessment of Cardiac Risk Resting & ambulatory ECG Exercise stress testing Echocardiography Pharmacologic stress testing

Dipyridamole/adenosine thallium scintigraphy

Dobutamine echocardiography Coronary angiography

ECG- CAD- in old MI ,inverted t-wave, prominent and

deep Q-wave, location dysrythmias Conduction defects Digitalis toxicity-inverted T-waves , downward

sloping of ST segment, narrow QRS complexes, atrial fibrillation.

Chamber enlargement like LVH in hypertensive patients.

Electrolyte imbalance AMBULATORY ECG monitoring-Confirms whether

patients' symptoms are coincident with cardiac arrhythmia, e.g.ventricular ectopic beats or atrial fibrillation ( palpitation)

RESTING ECHOCARDIOGRAPHY

USES - to detect presence & significance of valvular hrt ds ,

to detect CHD LVEF, chamber enlargement & hypertrophy RWMA – types & location

the assessment of resting LV fxn not routinely recommended for preop screening.

Resting LV Function Echocardiogram

Predictive value LVEF <35% leads to postop CHF No consistent correlation with postop

ischemia

Indications Poorly controlled CHF Unknown systolic or diastolic function in

valvular heart ds, long standing uncontrolled HTN

STRESS TESTING OPTIONS:- Exercise stress alone (usually Bruce

protocol) Exercise / pharmacological stress with

nuclear myocardial perfusion imaging (MPI)

Exercise stress echo Pharmacologic stress echo

Stress echocardiography:- To assess the myocardial function. Exercise stress echo- INDICATIONS- prior non diagnostic or if

likelihood of false positive ECG stress test, ECG abnormalities making interpretation of ECG stress testing difficult, for prognostic information post MI, to determine success of intervention .

In exercise stress echo-Images are obtained once pt hs achieved 85% of target HR to see wall motion abn during max workload and lastly recovery images with in 90 sec of peak HR.

INDICATION FOR PHARM STRESS ECHO:-Unable to exercise because of: Intermittent claudication Neurologic deficits Rheumatologic or orthopedic conditions Chronic lung disease Debilitation, old age

Simultaneous evaluation of ischemia and myocardial viability  

Inability to achieve target heart rate duringexercise because of therapy with High dose beta-blocker or calcium channel blocker

Dobutamine/dipyridamole/adenosine. Abn at rest signify scar ts. & abn with incr isotropy and

chronotropy indicates decrs blood flow.

INDICATIONS FOR EXERCISE STRESS TESTING (TMT) :-

Objective confirmation of ischemia Assessing extent of ischemia Documenting exercise capacity Functional assessment of known CAD Determining risk and prognosis Determining need for angiography

- High risk cut points Assessing response to treatment

C/I for stress testing:- Acute myocardial infarction (within two days) Unstable angina pectoris Uncontrolled arrhythmias causing symptoms of

hemodynamic compromise Symptomatic severe aortic stenosis Uncontrolled symptomatic heart failure Active endocarditis or acute myocarditis or

pericarditis Acute aortic dissection Acute pulmonary or systemic embolism Acute noncardiac disorders that may affect

exercise performance or may be aggravated by exercise

EXERCISE STRESS TESTING:- Treadmill testing / TMT

Bruce protocol -most popular 8 stages Incline and speed increment every 3 minutes interval

Target – to achieve 85-100% of maximum age predicted HR Achieve at least 6 METS for diagnostic accuracy. Continuous monitoring for symptoms, ECG and blood

pressure and heart rate. Decrease in coronary blood flow to blocked arteries result in

ECG changes and response in HR,BP as well. The accuracy in predicting CAD depends in part on pretest

likelihood of CAD in pts with risk factors.(BAYES THEORM) Prognostic gradient of ischemic response during TMT.

ECG pattern indicative of ischemia:-

HIGH RISK INDICATORS DURING TMT

Early positive-stage I: Mortality >5%/year Strongly positive > 2.5 mm ST depression ST elevation > 1 mm in leads without Q

waves Fall in SBP >10 mm Hg Early onset ventricular arrhythmia's Chronotropic incompetence Ex HR

<120/min not due to drugs Prolonged Ischaemic changes in recovery > 2mm lasting > 6 minutes in multiple leads

INDICATIONS FOR MYOCARDIAL PERFUSION IMAGING

Suspected false +ve or-ve TMT Resting ST changes LBBB,RBBB,LVH, digitalis, pre-excitation or

pacemaker Inability to exercise Prognosis of known CAD Detecting post PTCA or CABG ischemia Assessing myocardial viability Risk evaluation in non-cardiac surgery patients Assessment functional significance of

documented coronary stenosis

NUCLEAR CARDIAC IMAGING useful for assessing coronary perfusion, has greater sensitivity than exercise stress testing, it can assess LV size & fxn.Images taken in 2 phases: 1st imediately aftr cessation of exc , 2nd 4 hours later to detect reversible ischemia. Size of perfusion abn is the most important indicator of significant CAD

Hot spot- tech.99 pyrrophosphate

Taken up by infarcted segment.

Image detected after 12-14 hours.

Cold spot-thallium 201 Taken up by normal

myocardium. Image detected in 30-

60 min. Repeat imaging can be

done after 3-4 hours.

Pharmacological stress testing:-

Adenosine – direct vasodilator

Stenosed arteries already max. dilated, so it cnt dilate thm bt increase BF to healthy myocardium.

Causes bronchospasm and dec preload.

Dipyridamole is a indirect vasodilator

With coronary stenosis differential dilatation results in differential flow hence differential uptake of isotope

Side effects- same

Dobutamine –induces exercise like state

incrs HR and contractility

increases regional BF to

myocardium. Perfusion abn

seen in stenosed part.

CORONARY ANGIOGRAPHY INDICATIONS - Done in Pts having positive stress

tests suggesting significant myocardium at risk.

-To detect or exclude serious CAD i.e. left main or 3 vs ds.

-chronic stable angina pts who are severely symptomatic despite medical therapy

-Pts with ventricular dysfxn

-In young patients with VHD to rule out assoc. CAD before cardiac surgery.

-who r being considered 4 revascularization -Helps to decide how many bypass grafts should be performed

- 4 definitive diagnosis of CAD individuals whose occupations cud place others life in danger( pilots)

THANKS