Peri -Operative Cardiac Risk Reduction, A-fib/MI Management

1. Peri-Operative Cardiac Risk Reduction, A-fib/MI Management Jason E. Davis, MD

2. Surgery as a Controlled Injury • ~27 million non-cardiac surgeries per year • 1 – 1.5 million for pt’s w/ known cardiac disease • 3 – 4 million for pt’s with 3 or more risk factors for coronary artery disease (DM, smoking, etc) • Past 50 years in surgery • Dramatic changes in procedures • Improvements to survival

3. Surgery as a Controlled Injury • Predictable responses • Body doesn’t differentiate surgery from injury • Fight or flight, mobilization of energy stores • “Physiological Narrowing” • 20 years old and healthy generally tolerates stressors better than pt 80 years old • Graded neuro-endocrine response • Bigger surgery, bigger response

4. Predictable Responses • Anterior Pituitary • ACTH • Growth hormone • Prolactin • Endorphin • Posterior Pituitary • Arginine vasopressin • Adrenals • Cortisol • Epinephrine (rises until 3 hrs) • Norepinephrine (until 3 days)

5. Post-injury/surgery Defenses • Analgesia • Hypercoagulability (control of blood loss) • Mobilization of metabolic substrates (glucose) • Conservation of fluid, electrolytes

6. Consequences & Complications • Altered hemodynamics • Hypertension • Fluid and metabolite shifts • Tachycardia • Hypercoagulability • DVT, pulmonary embolus • Myocardial Ischemia • Congestive heart failure • Tachyarrhythmia • Hypokalemia • Hypomagnesemia • Immune suppression • Infectious complications • Hyperglycemia

7. Sequence of events • Defining overall risk • PMH = Opportunity to Prevent, Plan, Adapt • Highest risk for complications • First 3 days post-operatively • Corresponds to injury + response

8. Patient Selection • American Society of Anesthesiologists risk stratification and classification scheme • Class 1: Normal healthy patient • Class 2: Patient with mild systemic disease • Class 3: Severe systemic disease, limits function • Class 4: Incapacitating, constant threat to life • Class 5: Moribund, unlikely to survive +/- surgery • Class 6: Brain-dead organ donor

9. Patient Selection • American Society of Anesthesiologists risk stratification and classification scheme • Class 1: Mortality 0 – 2% • Class 2: Mortality 0.5 – 3% • Class 3: Mortality 5 – 10% • Class 4: Mortality 75% • Elective vs. Emergent: 2 – 3x risk • Also: Magnitude, Duration…

10. Eagle’s cardiac risk assessment http://www.fpnotebook.com/CV/Surgery/EglsCrdcRskAsmnt.htm • High Risk factors • Acute/recent MI • Unstable coronary dx • De-compensated CHF • Significant arrhythmias • Severe valvular disease

11. Eagle’s cardiac risk assessment http://www.fpnotebook.com/CV/Surgery/EglsCrdcRskAsmnt.htm • Intermediate Risk factors • Mild angina • History of MI, compensated CHF • Renal insufficiency, DM • Minor Risk Factors • Advanced age • Abnormal EKG • Low functional capacity

12. Further Pre-op Planninghttp://www.fpnotebook.com/CV/Surgery/AcAhPrprtvCrdcRskAsmnt.htm • Eagle’s cardiac risk assessment • >70 years age • History of angina • History of ventricular dysfunction • Diabetes on therapy • Abnormal Q-waves on EKG • ACC-AHA Criteria • Functional Capacity (I – IV) • Graded by “Metabolic Equivalents” (>4 METS = lower risk) • Detsky’s Modified risk index • Goldman criteria

13. Continuation of Medications • Beta-Blockers • Chronic users (AM w/ sip of water) • High risk non-users prescribed pre-op • Remember neuro-endocrine response • Anticoagulants – soon as outweighs bleeding • Coumadin • Interim heparin • Aspirin, Plavix • Statins – mixed literature

14. Attenuation of Stress Response • Pre-operative • Pre-emptive anesthesia (local, systemic) • Appreciate pt’s entire risk -- not just surgical! • Intra-operative • Product of underlying problems x surgical stress • Post-operative • Pain control • Fluid balance, early mobilization • Tx co-morbid conditions

15. Anesthetic Factors(collaboratively addressed with Anesthesia colleagues) • Anesthetic selection • Local +/- sedation • Regional (epidural, spinal, etc) • General • Temperature control • National initiatives to 37C • Improved bloodflow • Decreased neuro-endocrine

16. Atrial Fibrillation • Recognition • Irreg rhythm, tachycardia +/- CP, SOB, hypotension • Diagnosis • EKG, new onset often secondary to ischemia • Treatments • Attempt to normalize • B-blocker > Diltiazem > Digoxin • Rate control (often same meds) • Anticoagulation soon as poss • Prevent propagation thrombus

17. Myocardial Ischemia • Recognition • Tachycardia, hypotension, chest pain, new onset a-fib, shortness of breath, mental status change • Diagnosis • EKG, Troponin/CKMb, CXR (assess alt causes) • Treatment • B-blocker, nitrates, heparin, morphine, asa, statins • Cardiology consult PRN

18. LVHN Cardiology Consults • Lehigh Valley Heart Specialists • Nurse available on-call • Contact: • Lehigh Valley Heart Care Group • Fellow available on-call • Contact:

19. Summary • Consider whole pt • Surgery (controlled injury) + co-morbidities • Risk reduction • Pt stratification • Clearance, medications • Coordination of care • MI: dx, decrease work, decrease pain, +O2 • A-fib: ‘break’, rate, anticoag.

20. Thank you.