Risk Assessment and Stratification

Perioperative Pitfalls - Intro & Goals

• Perioperative Period Defined:
  • Pre-operative: Time before surgery.
  • Intra-operative: Duration of surgery.
  • Post-operative: Period after surgery.
• Primary Goals:
  • Identify patient-specific risks (cardiac, pulmonary, etc.).
  • Optimize co-morbidities pre-surgery.
  • Plan comprehensive perioperative care.
  • Ensure informed consent.
  • Crucially, it's about risk assessment, NOT 'medical clearance'.
• Core Components:
  • Detailed history.
  • Targeted physical examination.
  • Investigations: Guided by H&P and anticipated surgical risk.

⭐ The primary goal of preoperative evaluation is risk stratification and optimization, not to 'clear' a patient for surgery.

Heart Hazards - Cardiac Risk Check

• RCRI (Lee Index): 6 predictors for MACE.

  • 📌 RCRI: 'CREATININE' - CAD (IHD Hx), CHF Hx, CVA/TIA Hx, Preop Creatinine >2mg/dL, Insulin for DM, High-risk Surgery.
  • Risk: 0 pts: 0.4% MACE; 1 pt: 0.9%; 2 pts: 6.6%; ≥3 pts: 11%.

• METS: Functional capacity. <4 METS (e.g., can't climb 1 flight stairs) = poor, ↑ risk.

• ASA Physical Status Classification:

• High-Risk Cardiac Conditions (defer elective):

  • Recent MI (<30-60d), Unstable/Severe Angina.
  • Decompensated HF, Sig. Arrhythmias, Severe Valvular Dz.

• Preoperative Cardiac Evaluation Algorithm:

⭐ Continue chronic β-blockers. Avoid routine new β-blocker initiation on surgery day, esp. low/intermediate risk.

Lung Landmines - Pulmonary Perils

• Postoperative Pulmonary Complications (PPCs): Atelectasis, pneumonia, resp failure, COPD/asthma exacerbation.
• ARISCAT Score (Assess Respiratory Risk in Surgical Patients in Catalonia):
  • Components: Age, Preop SpO$₂$, Resp infection <1mo, Anemia (Hb<10 g/dL), Incision, Duration >2h, Emergency.
  • Risk: Low <26, Intermediate 26-44, High ≥45.
• Patient Factors: Age >60, COPD, asthma, smoking, OSA, CHF, dependence, low albumin (<3.5 g/dL).
• Procedure Factors: Site (thorax/upper abd.), >3h surgery, GA, emergency.
• OSA: 📌 STOP-BANG: Snoring, Tired, Observed apnea, Pressure, BMI >35 kg/m², Age >50, Neck >40cm, Male. Score ≥3 high risk.

⭐ Lung protective ventilation strategies intraoperatively and early postoperative mobilization are key to reducing PPCs.

Systemic Snafus - Beyond Heart & Lungs

• Renal Risk:
  • AKI predictors: CKD, eGFR <60, DM, HTN, CHF, contrast use, major surgery.
• Hepatic Risk:
  • Child-Pugh Score: (Components: Encephalopathy, Ascites, Bilirubin, Albumin, PT/INR). Classes A, B, C & operative mortality.
  • MELD Score: (Bilirubin, Creatinine, INR) - better for 30-day mortality.

  ⭐ For patients with cirrhosis, a MELD score ≥ 15 is associated with significantly increased perioperative mortality for elective non-hepatic surgery.

• Hematologic Risk:
  • Anemia: Preop Hb <7-8 g/dL (transfusion trigger).
  • VTE Risk: Caprini score for VTE prophylaxis.
  • Coagulopathy: Assess INR, aPTT, platelets.
• Endocrine Risk (Diabetes):
  • HbA1c target: <8% (acceptable); avoid >8.5-9%.
  • Perioperative glucose control: Target 140-180 mg/dL.
• Geriatric Considerations:
  • Frailty assessment, cognitive dysfunction (delirium risk), polypharmacy.

High‑Yield Points - ⚡ Biggest Takeaways

• RCRI (Revised Cardiac Risk Index) predicts MACE; components include IHD, CHF, CVA, DM (insulin), Cr >2 mg/dL, high-risk surgery.
• ASA classification strongly correlates with perioperative mortality and morbidity.
• Functional capacity <4 METs (Metabolic Equivalents) signifies poor reserve and ↑ cardiac risk.
• Key pulmonary risks: Age >60 years, COPD, active smoking, OSA, surgery duration >3 hours.
• Continue beta-blockers & statins if already prescribed; initiate cautiously in select high-risk patients.
• VTE prophylaxis (e.g., LMWH) is crucial, guided by risk scores like Caprini.
• Maintain perioperative blood glucose <180 mg/dL for optimal outcomes.