What are the treatment guidelines for open wound infections?

Treatment Guidelines for Open Wound Infections

The most important therapy for an open wound infection is to open the incision, evacuate infected material, and continue dressing changes until the wound heals by secondary intention, with antibiotics reserved for cases with systemic signs of infection or extensive local involvement. 1

Assessment and Classification

• Open wound infections should be assessed for severity based on extent of erythema, presence of systemic signs (fever, tachycardia, abnormal WBC), and patient risk factors 1
• Wound infections can be classified as:
  • Superficial (limited to skin/subcutaneous tissue)
  • Deep (involving fascia/muscle)
  • With or without systemic involvement 1

Initial Management

Superficial Wound Infections

• For superficial infections with <5 cm of erythema and minimal systemic signs (temperature <38.5°C, WBC <12,000/µL, pulse <100/min), surgical drainage alone without antibiotics is recommended 1
• Incision and drainage is the primary treatment for simple abscesses or boils 1
• Obtain cultures from deep tissue after wound cleansing and debridement, avoiding swab specimens when possible 1
• Continue dressing changes until the wound heals by secondary intention 1

Moderate to Severe Infections

• For patients with temperature >38.5°C, heart rate >110/min, or erythema extending >5 cm beyond wound margins, both drainage and antibiotics are indicated 1
• Prompt surgical consultation is recommended for aggressive infections with signs of systemic toxicity or suspicion of necrotizing fasciitis 1
• Debridement is crucial for removing devitalized tissue and reducing bacterial load 1

Antibiotic Selection

Empiric Therapy Guidelines

1. For mild to moderate infections in patients without recent antibiotic exposure, target aerobic Gram-positive cocci (GPC) 1

   • First-line options: First-generation cephalosporin (e.g., cefazolin) 2

2. For severe infections, start broad-spectrum empiric therapy pending culture results 1

   • Options include:
     • Vancomycin or linezolid plus piperacillin-tazobactam
     • Vancomycin or linezolid plus a carbapenem
     • Vancomycin or linezolid plus ceftriaxone and metronidazole 1

3. For wounds involving perineum or following operations on GI/female genital tract:

   • Use antibiotics with anaerobic coverage:
     • Cephalosporin plus metronidazole
     • Levofloxacin plus metronidazole
     • Carbapenem monotherapy 1

4. Consider MRSA coverage when:

   • Patient has prior history of MRSA infection
   • Local prevalence of MRSA is high
   • Infection is clinically severe 1
   • Options include: vancomycin, daptomycin, or linezolid 1

Route and Duration of Therapy

• Prefer parenteral therapy initially for severe and some moderate infections, with transition to oral agents when the patient is systemically well and culture results are available 1
• Highly bioavailable oral antibiotics alone may be used for most mild and many moderate infections 1
• Recommended duration:
  • 1-2 weeks for mild soft tissue infections
  • 2-3 weeks for moderate to severe infections 1
  • Continue antibiotics until, but not beyond, resolution of infection signs (not through complete wound healing) 1

Special Considerations

Diabetic Foot Infections

• Obtain plain radiographs to assess for bony abnormalities, soft tissue gas, or foreign bodies 1
• Consider MRI when soft tissue abscess is suspected or osteomyelitis diagnosis is uncertain 1
• Osteomyelitis should be considered with any infected, deep, or large foot ulcer, especially if chronic or overlying bone 1

Chronic Wound Infections

• Chronic wounds often involve biofilms, which contribute to excessive inflammation and delayed healing 3
• Maintenance debridement and topical antimicrobials (antiseptics) are more effective than antibiotics for biofilm control 3
• Systemic antibiotics should be reserved for treating spreading local and systemic infection 3, 1

Biofilm Management

• Biofilms contribute to delayed healing through excessive inflammation 3
• Control strategies include:
  • Regular debridement
  • Topical antiseptics
  • Negative pressure wound therapy with irrigation 1

Common Pitfalls to Avoid

• Overuse of antibiotics in chronic wounds contributes to antibiotic resistance without improving outcomes 4, 3
• Relying on swab cultures rather than deep tissue specimens after debridement provides less accurate results 1
• Continuing antibiotics through complete wound healing rather than stopping after resolution of infection signs 1
• Failing to recognize necrotizing infections requiring urgent surgical intervention 1
• Neglecting appropriate wound care (debridement, dressing changes) which is essential even when antibiotics are used 1