Preoperative Risk Assessment

Preoperative Risk Assessment - Risk Riddle Kickoff

• Goal: Identify patient & procedural risks; optimize patient condition; plan perioperative care.
• Key Components: History (comorbidities, medications, allergies, anaesthetic history), physical exam, targeted investigations.

ASA Physical Status Classification System

• Focus: Cardiovascular, respiratory, renal, endocrine, & hematologic systems.
• Consider: Functional capacity (METs - Metabolic Equivalents of Task). <4 METs indicates poor functional capacity. 📌 METs Mnemonic: 1 MET = At rest; 4 METs = Climb 1-2 flights of stairs; >10 METs = Strenuous sports.

Preoperative Risk Assessment - Heart Smart Checkup

• Goal: Identify & quantify cardiac risk before non-cardiac surgery.
• Key Components:
  • Clinical Evaluation: Focused history (chest pain, dyspnea, syncope) & physical exam.
  • Functional Capacity (METS):
    • Crucial predictor. METS < 4 (e.g., can't climb 1 flight of stairs) = Poor capacity, ↑ risk.
    • METS ≥ 10 (e.g., strenuous sports) = Excellent. levels activities chart)
  • Revised Cardiac Risk Index (RCRI): 📌 "I-CHEST-C" (factors: Insulin Rx, CHF, High-risk surgery, Elevated Creatinine >2mg/dL, Stroke/TIA, Ischemic hearT disease/CAD).
    • 1 point per factor.
    • MACE Risk: 0 pts (0.4%), 1 pt (0.9%), 2 pts (6.6%), ≥3 pts (11%).
• Baseline ECG: For age >40 with risk factors, or known cardiac disease.

⭐ An RCRI score of 0 indicates low risk (0.4% MACE), while a score of ≥3 indicates high risk (11% MACE) for major adverse cardiac events.

Preoperative Risk Assessment - Breath & Beyond Prep

• Pulmonary Risk:
  • ARISCAT Score (PPCs): Age, SpO2 (<96%), Resp. infection (last month), Anemia (Hb <10 g/dL), Incision (thoracic/upper abd), Surgery duration (>2h), Emergency.
  • Smoking: Stop 4-8 weeks pre-op.
  • FEV1 <1L or <30% predicted = high risk.
• Renal Risk:
  • Assess baseline eGFR/Cr. Serum Cr >2 mg/dL ↑ risk.
  • ESRD: Dialysis within 1 week pre-op.
• Hepatic Risk:
  • Child-Pugh Score: A (mortality 10%), B (30%), C (~75-80%).
  • MELD Score >15: High risk.
  • Acute liver failure: Contraindication.
• Endocrine Risk:
  • Diabetes: HbA1c <8%. Target BG 140-180 mg/dL. Hold oral agents, adjust insulin.
  • Thyroid: Ensure euthyroid state.
  • Adrenal insufficiency: Stress dose steroids (e.g., Hydrocortisone 100 mg IV for major surgery).

⭐ Patients on chronic steroids (>5mg prednisone/day for >3wks) need stress dose steroids perioperatively to prevent adrenal crisis.

Preoperative Risk Assessment - Pill Plan & Shield Up

• Pill Plan (Medication Management):
  • Anticoagulants:
    • Warfarin: Stop 5 days (INR <1.5). Bridge if high risk.
    • DOACs: Stop 24-72h (renal/drug dep.).
    • Aspirin: Continue (stents); stop 7d if high bleed risk.
    • Clopidogrel: Stop 5-7 days.
  • Diabetes: Metformin hold AM; adjust insulin (½ basal).
  • Antihypertensives: Continue β-blockers. Hold ACEi/ARBs AM.
  • Steroids: Stress dose (Hydrocortisone 100mg IV) if >5mg pred >3wks.
• Shield Up (Prophylaxis):
  • SSI: Antibiotics (Cefazolin) 30-60m pre-incision.
  • VTE: Risk-stratify (Caprini); LMWH/SCDs.
  • Aspiration: PPI/H2RA if high risk (GERD, emergency).

⭐ Continue β-blockers in chronic users to prevent MACE (Major Adverse Cardiac Events).

High‑Yield Points - ⚡ Biggest Takeaways

• ASA classification is paramount for overall perioperative risk stratification.
• RCRI predicts cardiac risk; key factors include IHD, CHF, CVA, DM (insulin), Cr >2, high-risk surgery.
• Functional capacity <4 METS signifies poor prognosis and ↑ surgical risk.
• Advise smoking cessation at least 4-8 weeks before surgery to reduce pulmonary issues.
• Optimize glycemic control (HbA1c ideally <7%) in diabetic patients preoperatively.
• Careful management of anticoagulants/antiplatelets, often requiring bridging, is essential.
• Child-Pugh score is used to assess risk in patients with liver cirrhosis.