Preoperative Risk Assessment

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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

ASA ClassDescriptionMortality Risk (Approx.)
ASA INormal healthy patient0.05%
ASA IIMild systemic disease0.4%
ASA IIISevere systemic disease4.5%
ASA IVSevere systemic disease, constant threat to life23%
ASA VMoribund, not expected to survive without operation51%
ASA VIDeclared brain-dead, organ donor-
EEmergency surgery (added to class)Doubles risk
  • 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. METS Score Examples for Preoperative Risk Assessment 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.

Practice Questions: Preoperative Risk Assessment

Test your understanding with these related questions

Which pre-operative investigation is recommended before surgical procedures in a patient on warfarin therapy?

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Flashcards: Preoperative Risk Assessment

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In a _____ position, the patient's head is elevated 15 - 30 degrees higher than the feet.

TAP TO REVEAL ANSWER

In a _____ position, the patient's head is elevated 15 - 30 degrees higher than the feet.

reverse trendelenberg

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