CAUSATIVE ORGANISMS

POLYMICROBIAL

• Perianal abscesses, penetrating abdominal trauma, surgical procedures involving bowel, decubitus ulcer, IV drug use, genital site or vulvovaginal infection
  • Mixed aerobic-anaerobic

MONOMICROBIAL

• Group A strep
• Staph aureus
• V. vulnificus
• A. hydrophilia
• Peptostreptococcus

RECOMMENDED EMPIRIC TREATMENT

1. Prompt surgical consultation for surgical intervention for patients with necrotizing fasciitis or gas gangrene
   1. Cultures should be done in OR to aid antibiotic therapy
   2. Blood cultures should be drawn
   3. Many patients require multiple surgical debridements
2. Antibiotic therapy should continue until no further surgical debridements are needed and the patient has improved clinically and has been afebrile for 48-72 hours.

EMPIRIC ANTIBIOTIC THERAPY

1. Vancomycin PLUS piperacillin/tazobactam 3.375 g IV q8h
2. Vancomycin PLUS cefepime 1 gm IV q8h PLUS metronidazole 500 mg IV q8h (or clindamycin 600-900 mg IV q8h if allergic to metronidazole)
3. Vancomycin PLUS levofloxacin 750 mg IV q24h PLUS metronidazole 500 mg IV q8h (or clindamycin 600-900 mg IV q8h if allergic to metronidazole)
4. Vancomycin PLUS meropenem 1g IV q8h (ID approval required)

POST CULTURE TREATMENT & ANTIBIOTIC SELECTION

1. Modify antibiotics according to culture results
2. If culture results with Grp A strep change to penicillin 2-4 million units IV q4-6h PLUS clindamycin 600-900 mg IV q8h
3. Get ID Consult

• If severe penicillin allergy
  1. MIXED INFECTION
     1. Clindamycin 600-900 mg IV q8h PLUS levofloxacin 750 mg IV q24h
     2. Metronidazole 500 mg IV q8h PLUS levofloxacin 750 mg IV q24h
     3. Clindamycin 600-900 mg IV q8h PLUS aminoglycoside (last line option)
  2. STAPH/STREP INFECTION
     1. Vancomycin
     2. Linezolid (Requires ID consult)
     3. Daptomycin​ (Requires ID consult)