What is the most appropriate initial management for a patient with mild swelling, erythema, and increased tenderness at a recent surgical incision, normal vital signs and white‑blood‑cell count, and no purulent drainage?

Management of Mild Surgical Site Infection

For a patient with mild swelling, erythema, and increased pain at a surgical wound with normal vital signs and white blood cell count, the correct answer is D: Observation and wound culture. 1

Clinical Rationale

When all of the following criteria are met, observation with proper wound care is sufficient without antibiotics: temperature <38.5°C, heart rate <100–110 bpm, erythema/induration <5 cm from the wound edge, white blood cell count <12,000 cells/µL, no purulent drainage, and no systemic toxicity. 2, 1 This represents normal postoperative inflammation rather than established infection requiring immediate antimicrobial therapy.

Role of Wound Culture

Obtaining a wound culture is essential when clinical suspicion of infection exists, as it identifies causative organisms and their antibiotic sensitivities should treatment become necessary. 1 The culture should be obtained using the Levine technique: cleanse the wound, apply pressure to express fluid from deeper tissue, then swab to reduce contamination from normal skin flora. 1

Why Other Options Are Incorrect

Surgical Exploration (Option A)

Surgical exploration is reserved for severe infections with profound toxicity, fever or hypotension despite antibiotics, skin necrosis with easy fascial dissection, or suspicion of necrotizing fasciitis. 1 This patient lacks these severe features. Early surgical site infections from Group A Streptococcus or Clostridium present with wound drainage visible on Gram stain and develop within 48 hours, not with mild symptoms and normal vital signs. 2

Discharge (Option B)

Discharging a patient with evolving wound infection symptoms without a monitoring plan is inappropriate; routine follow-up within 48–72 hours is essential to assess healing. 1 The patient requires observation to ensure symptoms do not progress to meet criteria for antibiotic therapy or surgical intervention.

IV Antibiotics (Option C)

IV antibiotics are indicated only when systemic signs develop: temperature ≥38.5°C, heart rate ≥110 bpm, erythema/induration >5 cm, white blood cell count >12,000 cells/µL, new purulent drainage, or evidence of systemic toxicity. 2, 1 Studies of subcutaneous abscesses found little or no benefit for antibiotics when combined with drainage in the absence of systemic signs. 2 A single published trial of antibiotic administration for surgical site infections specifically found no clinical benefit when systemic criteria were not met. 2

Management Algorithm

1. Examine the wound for purulence, extent of erythema (measure distance from wound edge), and signs of deeper involvement. 1

2. Assess vital signs and white blood cell count to stratify severity using the criteria above. 1

3. If no systemic signs are present: observe with proper wound care (daily dressing changes), obtain a culture using the Levine technique, and schedule 48–72 hour follow-up. 1

4. If systemic signs appear at follow-up: initiate a short 24–48 hour course of IV antibiotics. 2, 1 For clean wounds (trunk, head, neck, extremities), use cefazolin or vancomycin if MRSA risk is high. 1 For operations involving the GI tract or female genitalia, use cephalosporin plus metronidazole, levofloxacin plus metronidazole, or a carbapenem. 1

5. If purulent drainage develops: open the incision, evacuate infected material, and continue dressing changes until the wound heals by secondary intention. 2 Most surgical site infections require incision and drainage as the primary therapy, with antibiotics playing a secondary role. 2

Common Pitfalls to Avoid

• Do not order imaging (CT/ultrasound) for superficial infections; reserve it for suspected deep collections >3 cm. 1 Imaging delays definitive management and adds unnecessary cost without therapeutic benefit for superficial wounds.

• Do not rely on superficial swabs, which frequently grow contaminants rather than true pathogens. 1 Use the Levine technique to obtain specimens from deeper tissue.

• Avoid routine antibiotic use for superficial surgical site infections after adequate drainage unless systemic criteria are met. 2 Antibiotics are unnecessary when erythema is <5 cm and systemic signs are absent.

• Do not close infected wounds prematurely; allow healing by secondary intention with regular dressing changes. 2 The most important therapy for surgical site infection is opening the incision and evacuating infected material.

• Maintain high suspicion for rare but serious early infections (Group A Streptococcus, Clostridium) if symptoms develop within 48 hours, particularly if wound drainage is present with organisms on Gram stain but few white blood cells. 2 These require immediate surgical consultation and antistaphylococcal or anticlostridial treatment.