What is the treatment of choice for a surgical site infection?

Treatment of Surgical Site Infection

The cornerstone of surgical site infection treatment is immediate surgical drainage with incision opening, suture removal, and wound debridement—antibiotics are adjunctive and indicated only when systemic criteria are present. 1, 2

Immediate Surgical Management (Required First)

Surgical intervention must precede antibiotic therapy and includes: 1, 2

• Opening the incision widely to drain purulent material
• Removing sutures from the infected area
• Irrigating and debriding the wound thoroughly
• Obtaining Gram stain and culture before starting antibiotics 1, 2

The most common error in SSI management is prescribing antibiotics without adequate surgical drainage, which leads to treatment failure. 1, 2

When to Add Antibiotics

Antibiotics are indicated only if the patient meets systemic criteria: 1, 2

• Temperature ≥38.5°C
• Heart rate ≥110 beats/minute
• White blood cell count >12,000/μL
• Erythema extending >5 cm from wound edge
• Signs of organ failure
• Immunocompromised status

Antibiotic Selection by Surgical Site Location

For Trunk and Extremities (Away from Axilla/Perineum)

First-line oral options: 3, 1

• Cephalexin 500 mg every 6 hours (preferred for excellent S. aureus and streptococcal coverage) 1
• Dicloxacillin 500 mg four times daily 1
• Oxacillin 3
• First-generation cephalosporin 3

For Axilla, Perineum, or Groin Regions

These sites require coverage for gram-negative bacteria and anaerobes due to potential enteric contamination: 3, 1, 2

First-line options: 3, 2

• Amoxicillin-clavulanate (Augmentin) 875/125 mg twice daily or 500/125 mg three times daily 2
• Cefoxitin 3
• Ampicillin-sulbactam 3

Alternative combination therapy: 1

• Ciprofloxacin 750 mg twice daily PLUS metronidazole 500 mg three times daily
• Levofloxacin 750 mg daily PLUS metronidazole 500 mg three times daily

For MRSA-Suspected Infections

When MRSA is suspected (known colonization, high local prevalence >30%, or treatment failure): 3, 1

• Sulfamethoxazole-trimethoprim 1-2 double-strength tablets twice daily (preferred for efficacy and cost) 1
• Doxycycline 1
• Clindamycin 300-450 mg three times daily 1
• Linezolid 3, 1
• Vancomycin 15-20 mg/kg IV every 12 hours (for severe infections) 3
• Daptomycin (for severe infections) 3

Treatment Duration

Standard duration is 5-7 days after adequate surgical drainage for uncomplicated infections. 1, 2

Extended duration of 7-10 days is warranted for: 1, 2

• Deep tissue involvement
• Persistent systemic signs of infection
• Immunocompromised patients
• Inadequate clinical improvement within 5 days

Key Microbiology

The most common pathogens in SSIs are: 3, 4, 5

• Staphylococcus aureus (40-50% of cases, with MRSA representing 27-29%) 3
• Coagulase-negative staphylococci 3
• Escherichia coli 3
• Pseudomonas aeruginosa 3
• Enterococcus species 3

Critical Pitfalls to Avoid

Do not prescribe antibiotics without surgical drainage—this is the primary cause of treatment failure. 1, 2

Do not use beta-lactam monotherapy for axilla, perineum, or groin infections—these require gram-negative and anaerobic coverage. 1, 2

Do not empirically cover for MRSA unless risk factors are present—reserve anti-MRSA agents for documented infections or high-risk scenarios. 1, 2

Do not continue antibiotics beyond 7 days for uncomplicated infections after adequate drainage. 1, 2

Green discharge does not automatically indicate Pseudomonas infection—obtain cultures before escalating to anti-pseudomonal agents. 2

Special Considerations for Device-Related SSIs

For infections involving implanted devices (prosthetic mesh, cardiac devices): 1

• Device removal is typically required for treatment success
• Attempting to salvage the device with antibiotics alone has extremely high failure rates
• Consider endocarditis evaluation if bacteremia or persistent fever occurs