Anaesthesia for ischemic heart disease patient

Dr.Prabhu M.S

• 55 yrs old male patient• 4 months old MI • CA stomach – subtotal gatrectomy• On T.Aspirin 75 mg OD

T.Clopidogrel 75 mg ODT.Enalapril 2.5 mg BDT.Metoprolol 25 mg ODT.Atorvastatin 10 mg HS

• Blood investigation – WNL• ECG – ST and T V3-V6• ECHO – moderate LV sys

dys EF 40 %

Risk stratification

• GOLDMAN CARDIAC INDEXHISTORY AGE > 70 yrs 5Myocardial infarction in preceding 6 months 10PHYSICAL EXAMINATIONThird heart sound or gallop rhythm 11Aortic stenosis 3ECGRhythm other than sinus 75 ventricular ectopic / mt 7 POOR GENERAL STATUS 3SURGERYIntraperitoneal, intrathoracic, aortic 3Emergency 4

CLASS CARDIAC DEATH (%) LIFE THREATANING COMPLICATIONS (%)

0-5 0.2 0.7

6-12 2 5

13-25 2 11

>26 56 22

• All factors contribute equally to the index (with 1 point each), and the incidence of major cardiac complications is estimated at 0.4, 0.9, 7 and 11% in patients with an index of 0, 1, 2, and 3 points, respectively.

• T.Aspirin 75 mg OD T.Clopidogrel 75 mg OD T.Enalapril 2.5 mg BD T.Metoprolol 25 mg OD T.Atorvastatin 10 mg HS

ANAESTHETIC GOALS

• MAINTAINING MYOCARDIAL OXYGEN SUPPLY AND DEMAND• FACTORS DECREASING OXYGEN SUPPLY :

– DECREASED CORONARY BLOOD FLOW– TACHYCARDIA (LOW DIASTOLIC PERFUSION TIME)– HYPOTENSION– INCREASED PRELOAD– HYPOCAPNIA (CORONARY VASOCONSTRICTION)– CORONARY ARTERY VASOSPSM– DECREASED OXYGEN CONTENT AND AVAILABILITY– ANAEMIA– HYPOXEMIA– REDUCED OXYGEN RELEASE FROM HEMOGLOBULIN (pH, 2-3 DBG, temp)

ANAESTHETIC GOALS

• FACTORS INCREASING OXYGEN DEMAND :– Tachycardia– Increased wall tension– Increased preload– Increased afterload– Increased myocardial contractility

HISTORY

• Exercise tolerance• Angina pectoris – symptomatic manifestation of myocardial

ischemia evoked by physical exertion and relieved by nitrates

• Myocardial infarction according to Tarhan et al perioperative re infarction37 % - MI < 3 months16 % - MI 4-6 months5 % - > 6 months

• Co existing disease• Current medication• Cardiac failure

EXAMINATION

• Pallor, cyanosis, clubbing, odema, lymphadenopathy• Pulse rate and rhythm• Blood pressure• Jugular venous pulse• CVS - murmur, heart sounds• RS - any added sound• Other system examination.

INVESTIGATION

• Complete blood picture• RFT• Serum electrolytes• Platelet function analysis• Coagulation profile• ECG • ECHO• Stress test• angiography

ASSESSMENT

• ASA III• All drugs to be continued (except clopidogrel to be stopped

1 wk prior)• ACEI to be continued • Aspirin to be continued• Preop night sedation• Antacid prophylaxis

IN THEATRE

• MONITORS :NON INVASIVE :ECG (computerized ST analysis ), NIBP, SPO2, ETCO2,

Temp, urine outputINVASIVE :arterial BP, vigileo, CVP monitor

• Lead V4, V5 – 90 % sensitivity• Lead II, V4, V5 – 96 % sensitivity• CM5 , CB5 leads

IN THEATRE

• MONITORS :role of TEE

GENERAL ANAESTHESIA

• INTRAVENOUS ANAESTHESIA / HIGH OPIOID ANAESTHESIA

Premed : glycopyrrolate 5 mcg / kg (if required)

midazolam 0.05 mg/kg morphine 0.1 – 0.2 mg/kg / fentanyl 2- 5

mcg/kg Preoxy : 100 % O2 – 3 mts Induction : etomidate 0.2 – 0.3 mg/ kg

GENERAL ANAESTHESIA

• INTRAVENOUS ANAESTHESIA / HIGH OPIOID ANAESTHESIA

Morphine 0.5 – 1 mg/kg (or)Fentanyl 20 – 40 mcg/kg

+Midazolam 0.05 – 0.15 mg/kg

GENERAL ANAESTHESIA

• Muscle relaxant :Vecuronium 0.1 – 0.2 mg/ kgRocuronium 0.6 – 1 mg/kg

• MaintenanceN2O : O2 – 4:2

Volatile anaesthetics :

• VOLATILE ANAESTHTICSIschemic preconditioning

XENON :non inflammable, non pungent, odorlessB/G : 0.14MAC : 0.71no myocardial depression

INTRA OP PERIOD

• Fluid management according to CVP and SVV• Blood loss to be taken care of – anaemia can cause critical

reduction in myocardial oxygen supply in IHD pt.• Avoid hyperventilation• Maintain normothermia

INTRA OP PERIOD

PERIOPERATIVE HYPOTHERMIA COMPLICATION

Cardiac arrhythmia & ischemiaIncreased peripheral vascular resistancePlatelet dysfunctionLeft ODC

PREVENTION

Minimizing redistribution of heatcutaneous warminginternal warming

INTRA OP PERIOD

• Intraoperative ischemia :

Hemodynamically stable BBNTGHeparin after consulting with surgeon.

Hemodynamically unstable Inotropic supportIABPPlan earliest possible cardiac catheterization.

INTRA OP PERIOD

• Intraoperative arrhythmia : hemodynamically stable

IV amiodaroneventricular tachycardia

hemodynamically unstable

cardioversion

supraventricular tachy carotid massage BB, CCB

POST OP PAIN RELIEF

• Epidural analgesia• USG guided TAP block• IV opioid.

CARE IN POST OP PERIOD

• Continuous ECG monitoring• Continuation or institution of beta blockade• Temperature control• Provision of supplemental O2• Adequate post op pain relief• Maintain hemodynamics with IV fluids• DVT prophylaxis.