Management of Surgical Incision Site Infection
The primary and most critical treatment for surgical site infection is to open the incision, evacuate infected material, and perform dressing changes until healing by secondary intention; antibiotics are unnecessary for most superficial SSIs unless systemic signs of infection are present. 1
Initial Assessment and Diagnosis
Physical examination of the incision provides the most reliable diagnostic information. Look specifically for:
- Purulent drainage from the incision 1
- Local pain, swelling, and erythema 1
- Temperature >38.5°C or heart rate >100 beats/minute 1
- Erythema extending >5 cm from the wound edge 2
Important caveat: Most postoperative fevers are not associated with SSI, and flat erythematous changes without swelling or drainage in the first week often resolve without treatment. 1
Primary Treatment Algorithm
Step 1: Surgical Management (Always Required)
Open all infected wounds immediately - this is the cornerstone of treatment and takes priority over antibiotics. 1
- Evacuate all infected material 1
- Irrigate the wound 1
- Continue dressing changes until healing by secondary intention 1
- Consider negative pressure wound therapy for high-risk patients 1
Step 2: Determine Need for Antibiotics
Antibiotics are NOT needed if: 1
- Minimal surrounding cellulitis (<5 cm of erythema and induration) 1
- Temperature <38.5°C AND pulse <100 beats/minute 1
- Patient is immunocompetent 1
Antibiotics ARE indicated if any of the following: 1
- Temperature ≥38.5°C 1
- Heart rate ≥100 beats/minute 1
- Erythema extending ≥5 cm from wound 2
- Signs of organ dysfunction (hypotension, oliguria, altered mental status) 1
- Immunocompromised patient 1
Antibiotic Selection (When Indicated)
For Clean Procedures (No GI/Genitourinary Tract Entry)
The most common pathogens are S. aureus (including MRSA) and streptococcal species. 1
First-line empiric therapy:
- Cefazolin 2g IV every 8 hours (adjust for renal function) 2
- If MRSA risk factors present: Vancomycin 15 mg/kg IV every 12 hours 2
For penicillin allergy:
For Procedures Involving GI/Genitourinary Tract
These infections have mixed gram-positive, gram-negative, and anaerobic flora. 1
Empiric coverage options: 1
- Cefoxitin 2
- Ampicillin-sulbactam 2
- Cephalosporin plus metronidazole 2
- Levofloxacin plus metronidazole 2
For Axillary or Perineal Incisions
These sites have higher rates of gram-negative organisms and anaerobes. 1
Recommended coverage:
- Broader spectrum agents covering gram-negatives and anaerobes 1
- Metronidazole plus fluoroquinolone or cephalosporin 2
Duration of Antibiotic Therapy
Standard duration: 24-48 hours for most cases 1
- Short course of 5-7 days maximum after adequate drainage 2, 3
- Longer courses are unnecessary and promote antibiotic resistance 2
- Deep infections with retained hardware may require 4-6 weeks IV antibiotics 2
Critical Pitfalls to Avoid
Never rely on antibiotics alone without drainage - this leads to treatment failure. 2 Studies of subcutaneous abscesses found no benefit for antibiotics when combined with drainage, and the single published trial of antibiotic therapy for SSIs found no clinical benefit. 1
Do not prescribe antibiotics for simple seromas without infection signs, as this promotes resistance without clinical benefit. 2
Do not extend antibiotic courses beyond 7 days for most SSIs after adequate drainage. 2
Do not assume all postoperative fever is SSI - fever usually does not occur immediately after operation and most postoperative fevers have other causes. 1
Special Considerations
For morbidly obese patients or those with deep multilayer wounds (thoracotomy), external signs of SSI may appear very late but will always eventually manifest. 1
If an SSI does not resolve as expected after treatment, investigate for possible deeper organ/space infection. 1
Gram stain and culture of wound contents can support empirical antibiotic choice, though treatment should not be delayed for culture results. 1