What is the treatment for necrotizing skin and soft tissue infections?

Treatment of Necrotizing Skin and Soft Tissue Infections

Immediate aggressive surgical debridement is the primary life-saving intervention for necrotizing soft tissue infections (NSTI), combined with broad-spectrum antibiotics and hemodynamic support—surgery must not be delayed for imaging or other diagnostic tests. 1

Surgical Management

Immediate Operative Intervention

• Surgical debridement should be performed immediately after fluid resuscitation, as delays beyond 24 hours after recognition result in 70% mortality versus 36% mortality when surgery occurs within 24 hours 2
• The operation must be radical, removing all devitalized tissue regardless of tissue loss—conservative surgery attempting to preserve tissue results in 71% mortality versus 43% mortality with initial radical debridement 2
• At operation, the fascia appears swollen and dull gray with stringy areas of necrosis, a thin brownish exudate (not true pus), and tissue planes that can be dissected with a gloved finger or blunt instrument 1

Repeat Debridement Protocol

• Patients must return to the operating room 24-36 hours after initial debridement and daily thereafter until no further necrosis is found 1, 3
• Procalcitonin ratio (day 1 to day 2) above 1.14 indicates successful surgical source control with 83.3% sensitivity and 71.4% specificity 1

Antibiotic Therapy

Empiric Regimen Selection

Broad-spectrum empiric antibiotics must cover gram-positive (including MRSA), gram-negative, and anaerobic organisms because 76% of cases are polymicrobial 1, 2

For Polymicrobial Necrotizing Fasciitis:

• Vancomycin, linezolid, or daptomicin (for MRSA coverage with toxin suppression benefit) 1, 3
• PLUS piperacillin-tazobactam (in settings without high ESBL prevalence) 1, 3
• OR meropenem/imipenem-cilastatin/doripenem (in settings with high ESBL prevalence or for Pseudomonas coverage) 1, 4
• Alternative: Ceftriaxone plus metronidazole, or fluoroquinolone plus metronidazole 3

For Group A Streptococcal Necrotizing Fasciitis:

• Clindamycin plus penicillin (clindamycin inhibits toxin production) 1, 3

Antibiotic Duration

• Continue antibiotics until repeated debridement is no longer necessary, the patient has clinically improved, and fever has been absent for 48-72 hours 1, 3
• In patients without secondary complicating infections, a 7-day course after final operative debridement is typically sufficient 5
• Procalcitonin monitoring may guide antibiotic discontinuation 1
• Adjust antibiotics based on culture results and sensitivities once available 1

Supportive Care

Fluid Resuscitation

• Aggressive fluid administration is mandatory because these wounds discharge copious amounts of tissue fluid 1, 3
• Hemodynamic support must be provided for sepsis and shock 1

Wound Management

• Negative pressure wound therapy (NPWT) should be considered after complete removal of necrosis to promote granulation tissue formation, reduce edema, and absorb exudates 1
• For Fournier's gangrene with fecal contamination, consider fecal diversion via colostomy or rectal diversion devices with NPWT to prevent wound contamination 1

Critical Pitfalls to Avoid

• Do not delay surgery for imaging studies (CT/MRI)—clinical judgment is paramount, and requesting imaging may delay definitive treatment 1
• Do not perform conservative debridement attempting to preserve tissue—this significantly increases mortality 2
• Do not rely on single clinical signs like tissue gas, fever, or WBC count for diagnosis or treatment decisions, as these are neither sensitive nor specific 1, 5, 2
• Do not use narrow-spectrum antibiotics empirically—the polymicrobial nature demands broad coverage from onset 2
• If necrotizing infection is suspected but uncertain, perform exploratory incision in the area of maximum suspicion—if no necrosis is found, the procedure can be terminated with minimal morbidity 1

Multidisciplinary Approach

• Coordination between surgeons, intensivists, and infectious disease specialists is mandatory from initial treatment 1
• Long-term management requires wound care specialists, physical therapy for functional recovery, and reconstructive surgery 1