What is the first step in managing a postoperative fever on day 4 in a patient who underwent a sigmoid resection?

First Step: Examine the Surgical Wound

On postoperative day 4 after sigmoid resection, the first step is to examine the surgical wound by removing the dressing and thoroughly inspecting for signs of surgical site infection. 1

Why Wound Examination Takes Priority on Day 4

• By postoperative day 4 (96 hours), fever is equally likely to be caused by a surgical site infection or another infection, making wound examination the critical first step 1
• The Infectious Diseases Society of America mandates removing surgical dressings to inspect wounds when new or persistent fever occurs days after surgery 1
• Surgical site infections rarely occur during the first 48 hours after surgery, but after 96 hours the risk becomes substantial, particularly after gastrointestinal procedures like sigmoid resection 1

What to Look for During Wound Examination

• Inspect thoroughly for purulent drainage, spreading erythema, induration, warmth, tenderness, or swelling 1
• Measure the extent of any erythema from the incision edge 2
• Look for any necrosis of the wound edges 1
• Assess for severe pain disproportionate to the expected postoperative course 2

When Immediate Intervention is Required

• If erythema extends >5 cm from the incision with induration, or if any necrosis is present, immediate intervention is required with opening of the suture line, empiric antibiotics, and dressing changes 1
• For sigmoid resection infections, empiric coverage must include both aerobic and anaerobic bacteria: cephalosporin + metronidazole, levofloxacin + metronidazole, or carbapenem 1
• Obtain Gram stain and culture of any purulent drainage before starting antibiotics 2

When to Obtain Blood Cultures

• Blood cultures should be obtained when temperature ≥38°C is accompanied by systemic signs of infection beyond isolated fever, such as hemodynamic instability, altered mental status, or signs of bacteremia/sepsis 1
• Blood cultures are not the first step unless the patient appears systemically ill 1

When Chest X-ray is Indicated

• Chest X-ray is not mandatory on day 4 if fever is the only indication 1
• Chest X-ray becomes indicated if respiratory symptoms develop 1, 2
• During the first 72 hours postoperatively, chest radiograph is generally unnecessary if fever is the only finding 2

Common Pitfalls to Avoid

• Do not assume atelectasis without investigation - atelectasis should be a diagnosis of exclusion 3
• Do not start empiric antibiotics before obtaining cultures, as this compromises diagnostic accuracy 3
• Do not perform extensive workup with cultures and imaging before examining the wound, as physical examination has the highest yield 4
• Rare but serious early infections (Group A streptococcal and clostridial infections) can develop 1-3 days post-surgery and require immediate recognition, though these are uncommon 1

Red Flags Requiring Immediate Escalation

• Hemodynamic instability or signs of severe sepsis 1, 3
• Respiratory compromise or altered mental status 1, 3
• Severe systemic toxicity suggesting necrotizing infection 2
• Persistent fever beyond 48-72 hours despite appropriate therapy 1, 3