pre-op evaluation in patients with cvs ds for non- cardiac surgery
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MODERATOR- DR. DARA SINGH PRESENTED BY- DR. ANUPAM . PRE-OP Evaluation IN PATIENTS WITH CVS DS for non- cardiac surgery. . PURPOSE OF PRE-OP EVALUATION. To identify the patients at risk for peri -op cardiac complications. - PowerPoint PPT PresentationTRANSCRIPT
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 MortalityHigh (>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 ageSimultaneous 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