What is the best approach for treating an incision infection, considering the severity of the infection and potential causative organisms?

Treatment of Incision Infection

The primary treatment for an incision infection is prompt and wide opening of the surgical incision to evacuate infected material, with antibiotics reserved only for patients showing systemic signs of infection (SIRS criteria, organ failure), immunocompromise, or specific clinical parameters (temperature >38.5°C, heart rate >110 bpm, or erythema extending >5 cm from wound edge). 1, 2

Initial Management: Incision and Drainage

Most incisional surgical site infections (SSIs) can be managed with incision and drainage alone without antibiotics. 2 The fundamental approach involves:

• Open the incision promptly and widely to evacuate all infected material and prevent progression of infection 1, 2
• Continue dressing changes until the wound heals by secondary intention 2
• Dress the wound to allow daily inspection while promoting a moist healing environment 3
• No specific dressing type has proven superior; convenience and cost guide selection 3

Delayed drainage can lead to progression of infection and deeper tissue involvement, making prompt surgical intervention crucial. 2

When to Add Antibiotics

Antibiotics are NOT routinely indicated for incisional SSIs. 2 Add antibiotic therapy only when:

Systemic Indicators Present:

• Any SIRS criteria (Systemic Inflammatory Response Syndrome) 1, 2
• Signs of organ failure: hypotension, oliguria, decreased mental alertness 1
• Temperature >38.5°C 2, 3
• Heart rate >110 beats/minute 2, 3
• Erythema extending >5 cm from wound edge 2, 3

Patient-Specific Factors:

• Immunocompromised status 1, 2

If antibiotics are needed, a short course of 24-48 hours is usually sufficient after adequate drainage. 2, 3

Antibiotic Selection by Surgical Site

For Trunk or Extremity Operations (Away from Axilla/Perineum):

Target staphylococci with: 2

• Oxacillin or nafcillin 2g every 6h IV
• Cefazolin 0.5-1g every 8h IV 2, 4
• Cephalexin 500mg every 6h orally

For Operations Involving Intestinal or Genital Tracts:

Single-drug options: 2

• Piperacillin-tazobactam
• Ertapenem
• Other broad-spectrum agents

Combination options: 2, 5

• Ceftriaxone + metronidazole
• Ciprofloxacin + metronidazole

For Operations Involving Axilla or Perineum:

Metronidazole plus one of: 2

• Ciprofloxacin
• Levofloxacin
• Ceftriaxone

MRSA Coverage:

Add vancomycin 15 mg/kg every 12h IV if MRSA is suspected, particularly in patients with: 1, 2

• Long-stay care facility residence
• Hospitalization within preceding 30 days
• Recent antibiotic exposure (beta-lactams, carbapenems, quinolones)
• Age ≥75 years
• Prosthesis implantation 1

Pathogen Considerations

Clean Surgery (No GI/GYN/Respiratory Tract Entry):

• Staphylococcus aureus from skin flora or exogenous sources is the usual pathogen 1
• Groin procedures may involve Gram-negative bacteria despite being "clean" 1

Clean-Contaminated or Contaminated Surgery:

• Aerobic and anaerobic pathogens from endogenous microflora of the resected organ 1
• Polymicrobial infections common 1

Nosocomial Postoperative Infections:

Broader coverage needed for: 1

• Pseudomonas aeruginosa
• Enterobacter spp.
• Proteus spp.
• MRSA
• Enterococci
• Candida spp.

Critical Pitfalls to Avoid

Failure to recognize deeper infection: Any deep SSI that does not resolve as expected after treatment should be investigated as possible organ/space infection. 2

Routine antibiotic use without systemic signs: This represents overtreatment and contributes to resistance without improving outcomes. 1, 2

Inadequate drainage: Opening only part of the incision or delayed intervention allows infection progression. 2

Missing MRSA risk factors: Failure to add vancomycin in high-risk patients can lead to treatment failure. 1

Follow-Up and Monitoring

• Plan first re-examination within 12-24 hours 3
• Repeat evaluations until wound shows clear healing signs 3
• Re-evaluate sooner if clinical worsening or laboratory parameters deteriorate (particularly WBC count) 3
• For wounds with significant drainage, consider vacuum-assisted closure devices to manage exudate and promote granulation 3

Special Considerations

Superficial vs. Deep Incisional SSIs: Superficial infections are most common and typically respond to drainage alone, while deep incisional SSIs cause greater morbidity and may require antibiotics even without obvious systemic signs. 1

Culture guidance: If specific organisms are identified, adjust therapy accordingly rather than continuing empiric broad-spectrum coverage. 3

No role for postoperative antibiotic prophylaxis: There is no evidence supporting routine postoperative antibiotics to prevent SSIs. 1