Perioperative Management of Comorbidities

Cardiovascular Comorbidities - Heart Matters Most

• Risk Stratification:
  • Revised Cardiac Risk Index (RCRI) for Major Adverse Cardiac Events (MACE):
    • Components: High-risk surgery, Hx Ischemic Heart Disease (IHD), Hx Congestive Heart Failure (CHF), Hx Cerebrovascular Accident (CVA)/Transient Ischemic Attack (TIA), Insulin-dependent Diabetes Mellitus, Preoperative Creatinine >2 mg/dL.
    • Score 0: 0.4% MACE; 1: 0.9%; 2: 6.6%; ≥3: 11%.
• Hypertension (HTN):
  • Goal: BP <140/90 mmHg.
  • Delay elective surgery if BP >180/110 mmHg.
  • Continue β-blockers. Consider holding ACE inhibitors/ARBs on surgery day (risk of hypotension).
• Ischemic Heart Disease (IHD):
  • Post-Myocardial Infarction (MI): Delay elective surgery >60 days.
  • Post-Percutaneous Coronary Intervention (PCI): Bare Metal Stent (BMS) 4-6 weeks; Drug-Eluting Stent (DES) 6-12 months.
  • Aspirin: Continue for high CV risk; stop 7 days prior if high bleed risk surgery.
• Heart Failure (HF):
  • Optimize volume status & medical therapy. Ejection Fraction (EF) <35% indicates ↑ risk.
• Valvular Heart Disease:
  • Severe Aortic Stenosis (AS): Aortic Valve Area (AVA) <1 cm², mean gradient >40 mmHg. High risk; consider Aortic Valve Replacement (AVR) pre-op.

⭐ Continuation of beta-blockers perioperatively is crucial for patients on chronic therapy.

Respiratory & Diabetic Care - Lungs & Glucose Go-Tos

Respiratory - Preoperative:

• Smoking cessation: 4-8 weeks prior.
• PFTs for high-risk (e.g., FEV1 < 50%).
• Asthma: Continue meds; pre-op steroids if FEV1 < 80% or recent exacerbation.
• COPD: Optimize bronchodilators.

Respiratory - Postoperative:

• Incentive spirometry, deep breathing.
• Early mobilization, adequate analgesia.

Diabetes Mellitus - Perioperative:

• Goal: HbA1c < 8%.
• Medications:
  • Stop Metformin 24-48h prior.
  • Hold other oral hypoglycemics (OHAs) day of surgery.
  • Adjust insulin: Continue basal, hold/reduce prandial.
• Monitoring: Frequent blood glucose (BG).

⭐ Target perioperative BG: 140-180 mg/dL. IV insulin if BG consistently > 180 mg/dL.

📌 Lungs: Stop smoking, PFTs, Optimize meds, Post-op physio. 📌 Glucose: HbA1c <8%, Hold OHAs (Metformin early), Insulin adjust, Target 140-180 mg/dL.

Renal & Hematologic Management - Kidney & Clotting Care

• Renal Function Assessment & Care:
  • Calculate eGFR pre-op. Cockcroft-Gault: $CrCl = \frac{((140 - Age) \times Wt_{kg} \times [0.85 \text{ if female}])}{(72 \times SCr_{mg/dL})}$.
  • Adjust drug dosages if eGFR < 60 mL/min/1.73m².
  • Maintain euvolemia; avoid nephrotoxic agents to prevent AKI.
• Hematologic Considerations:
  • Anemia: Consider transfusion if Hb < 7-8 g/dL, or if patient is symptomatic.
  • Anticoagulation Management:
    • Warfarin: Stop 5 days pre-op. Target INR < 1.5.
    • LMWH: Stop 12-24h (prophylactic dose) or 24-48h (therapeutic dose) pre-op.
    • DOACs: Stop 1-5 days pre-op, depending on specific agent and renal function.
  • Thrombocytopenia: Aim for platelet count > 50,000/μL for most surgeries; > 100,000/μL for neurosurgery/ophthalmic surgery.

⭐ For elective surgery, Warfarin is typically stopped 5 days prior and bridged with LMWH if high thrombotic risk.

Hepatic & Other Endocrine - Glands & Gut Guards

• Hepatic Dysfunction:
  • Assess severity: Child-Pugh (Bilirubin, Albumin, INR, Ascites, Encephalopathy), MELD (Bilirubin, INR, Creatinine).
  • Optimize: Correct coagulopathy (Vit K, FFP), manage ascites, treat encephalopathy.
  • Delay elective surgery if acute hepatitis or decompensation.
• Thyroid Disorders:
  • Hypothyroid: Continue levothyroxine. Severe (myxedema) - postpone elective surgery.
  • Hyperthyroid: Achieve euthyroid state pre-op (antithyroid drugs, β-blockers). Risk of thyroid storm.
• Adrenal Gland:
  • Adrenal Insufficiency: 📌 Stress dose steroids.
    • Minor surgery: Hydrocortisone 25mg IV pre-op.
    • Moderate: Hydrocortisone 50-75mg IV pre-op, then taper.
    • Major: Hydrocortisone 100-150mg IV pre-op, then taper.
  • Pheochromocytoma: Pre-op α-blockade (e.g., phenoxybenzamine) then β-blockade.

⭐ Patients on chronic steroids (e.g., >5mg prednisone daily for >3 weeks, or equivalent) require perioperative stress dose steroids.

High‑Yield Points - ⚡ Biggest Takeaways

• Continue beta-blockers; hold ACEi/ARBs on surgery day.
• Target perioperative glucose 140-180 mg/dL for diabetics.
• Delay elective surgery: 4-6 weeks post-MI, 6 months post-Drug Eluting Stent.
• Smoking cessation ≥4-8 weeks preoperatively significantly reduces pulmonary risk.
• Bridge anticoagulation (e.g., warfarin to heparin) for high-risk thromboembolic patients.
• Optimize severe COPD/asthma; ensure euthyroid state before thyroid surgery.
• Child-Pugh score assesses risk in liver disease; correct coagulopathy_