Postoperative management

Postoperative complications

Cardiovascular & Pulmonary Complications

• Postoperative MI
  • Usually POD 2-3. Often silent (no chest pain) due to analgesia/anesthesia. c
  • Risk Factors: Pre-existing CAD, CHF, CKD, diabetes mellitus, advanced age (> 65), and high-risk surgical procedures (e.g., vascular, prolonged open abdominal/thoracic surgeries).
  • Pathophysiology: Usually due to surgical stress (↑ catecholamines causing ↑ myocardial oxygen demand/tachycardia) superimposed on baseline CAD (demand ischemia/Type 2 MI), or plaque rupture (Type 1 MI) secondary to hypercoagulability/inflammation.
  • Presentation: Hypotension, arrhythmias, dyspnea, new-onset HF.
  • Dx: ECG, Troponins.
  • Tx: PCI or medical management (Aspirin, statin, beta-blocker if hemodynamically stable).
• ARDS (Acute Respiratory Distress Syndrome)
  • Post-trauma, massive transfusion, or sepsis.
  • Dx: Bilateral opacities on CXR, PaO2/FiO2 < 300.
  • Tx: Mechanical ventilation with low tidal volumes (6 mL/kg) & PEEP.
• Postoperative atelectasis

  • Most common after thoracic or upper abdominal surgeries.

  • PE: ↓ breath sounds, dullness to percussion, basilar crackles.

  • Management

    1. First-line / Prevention: Incentive spirometry (NBS & best preventive measure), early ambulation. c
    2. Second-line: Optimize pain control (e.g., epidural/PCA to allow deep breaths).
    3. Refractory: CPAP/BiPAP for persistent hypoxemia.
• Postoperative pneumonia
  • Management
    • Prevention (Most Important):
      • Incentive spirometry, deep breathing exercises. c
      • Early mobilization.
      • Adequate post-op pain control (epidural/regional blocks preferred over high-dose opioids to prevent hypoventilation).
    • First-line (Empiric Antibiotics): Must target Gram-negatives (including Pseudomonas) and Gram-positives (including MRSA) based on local antibiogram.
      • Pseudomonas coverage (choose 1): Piperacillin-tazobactam (Zosyn), Cefepime, or Meropenem.
      • MRSA coverage (choose 1): Vancomycin or Linezolid.
    • Second-line / De-escalation: Narrow Abx spectrum based on sputum/blood culture results after 48-72 hours. Duration: Typically 7 days for uncomplicated HAP.
    • Supportive: Supplemental $O_2$ (maintain $Sp{O}_2>92\%$), chest physiotherapy, aggressive pulmonary toilet.

Acute Postoperative Mediastinitis

• Epidemiology & Risk Factors
  • < 14 days post-median sternotomy (CABG/valves).
  • Orgs: S. aureus, S. epidermidis.
  • Risks: DM, obesity, smoking, reoperation.
• Clinical Features
  • Fever, tachycardia, purulent wound drainage.
  • Buzzword: Sternal instability (“clicking” or “rocking” w/ breathing).
• Diagnosis
  • Initial: Blood & wound cx, CBC (↑ WBC).
  • Imaging: CT Chest w/ contrast (mediastinal fluid/gas). Note: Small amt of pneumomediastinum on CXR is normal < 14 days post-op; worsening gas is pathologic.
  • Confirmatory: Surgical exploration w/ positive cx.
• Differential Diagnostics
  • Superficial Skin Infection: Intact sternum (no clicking), no systemic toxicity.
  • Postpericardiotomy Syndrome: Autoimmune, weeks-months later. Pleuritic pain, friction rub. Tx: NSAIDs.
  • Non-infectious Dehiscence: Sternal clicking without fever or purulence (mechanical failure).
• Management
  1. Surgical (Immediate): Urgent exploration, debridement, & sternal fixation (muscle flaps). c
  2. Medical: Empiric IV Abx (Vanco + Cefepime) targeting MRSA/Gram-negatives.
  3. Ongoing: 4-6 wks IV Abx tailored to cx.
• Complications
  • Sepsis / Septic shock (high mortality).
  • Sternal osteomyelitis.