Necrotising Fasciitis: Recent Management

Classification

Clinical Presentation

• Oedema extending beyond visible skin erythema
• Woody-hard texture of subcutaneous tissue
• Inability to distinguish fascial planes on palpation
• Disproportionate pain relative to skin changes
• Skin vesicles/bullae, soft-tissue crepitus
• Absence of lymphangitis

Figure: NF at presentation (a) - dusky, necrotic skin with progressive involvement

Figure: Rapid progression seen after 24 hours (b) - extensive devitalised tissue

Diagnosis

Clinical - Gold Standard

LRINEC Score

• Score ≥6: PPV 92%, NPV 96% for NF
• Score >8: significantly higher mortality and amputation risk
• Limitations: influenced by infection site, bacterial type, renal function, and peripheral vascular disease

Imaging

• Plain X-ray: may show gas in soft tissues (sensitive but non-specific)
• CT scan: modality of choice - shows fascial plane thickening, gas tracking along fascia, fluid collections. Do NOT delay surgery for CT if clinical suspicion is high.
• MRI: most sensitive but impractical in the emergency setting
• Radiology (Grainger & Allison's) documents NF as a recognised imaging entity requiring urgent communication

Microbiology

Management: The Five Pillars

1. Resuscitation and ICU Care

• Immediate IV access, aggressive fluid resuscitation
• Haemodynamic monitoring - arterial line, consider CVP/invasive monitoring
• Oxygen supplementation; endotracheal intubation if airway compromised
• Treat septic shock per Sepsis-3 bundle: broad-spectrum antibiotics, rapid fluid resuscitation, vasopressors to maintain MAP ≥65 mmHg
• DVT prophylaxis (tiered strategy - 2025 Consensus, Recommendation 13)
• Nutritional support: early enteral nutrition given the massive metabolic demand

2. Early Surgical Debridement (Cornerstone of Treatment)

"In cases where NF is highly suspected, surgical exploration should be conducted without delay."

• Timing: ideally within 6 hours of presentation (JAMA Surg 2024)
• Remove all devitalised tissue generously, going beyond the area of induration to clearly viable, bleeding tissue
• Wound is lightly packed with gauze after debridement
• Repeat debridements every 12-24 hours (some centres go daily) until no necrotic tissue remains and the patient shows clinical improvement
• Intraoperative cultures at every debridement
• Amputation is reserved for limbs with extensive muscle necrosis where function cannot be restored; it may be life-saving when fasciitis continues to spread despite debridement

3. Antimicrobial Therapy

• Antibiotics should be tailored based on intraoperative tissue culture results
• Duration: minimum 48-72 hours of initial therapy; extend to 2 weeks for severe disease
• For septic shock/organ dysfunction: highest-efficacy, broad-spectrum agents chosen rapidly
• Antibiotics should continue at minimum until debridement is complete and clinical improvement is evident

4. Wound Management and Reconstruction

• Vacuum-assisted closure (VAC) therapy after debridement accelerates wound healing and reduces the need for repeated theatre visits
• Early split-skin grafting in selected cases minimises protein and fluid losses (Bailey & Love)
• Reconstruction may require skin grafting, flap closure, or other techniques analogous to burn surgery
• Diverting colostomy may be needed to keep perineal wounds clean (Fournier's gangrene)

5. Adjunct Therapies

Hyperbaric Oxygen Therapy (HBOT)

• 2025 Expert Consensus (Recommendation 14, weakly recommended): "For patients with NF who have stable systemic conditions and can be safely transported, HBOT is recommended (evidence level: high)"
• Bailey & Love: mortality reduced to 9-20% with HBO vs 30-50% without
• Mechanism: enhances oxidative killing of anaerobes, promotes angiogenesis, boosts neutrophil function
• Not all centres have access; patient must be haemodynamically stable for transfer
• JAMA Surgery 2024 notes insufficient data to support routine use, but it remains a reasonable adjunct where available

Intravenous Immunoglobulin (IVIG)

• Proposed especially for Type II (GAS) NF - neutralises streptococcal superantigens (toxins responsible for the cytokine storm)
• Current evidence is insufficient to recommend routine use (JAMA Surg 2024; Curr Opin Infect Dis 2024)
• Some guidelines suggest consideration in severe GAS-associated toxic shock syndrome
• Ongoing trials are needed

Scoring and Prognosis

• Haemorrhagic bullae at presentation
• Peripheral vascular disease
• LRINEC score >8
• Bacteraemia
• Late amputation vs early amputation
• Septic shock on presentation
• Delayed time-to-surgery (>12-24 hours)

Special Variants

Summary Algorithm

High clinical suspicion of NF
         ↓
Immediate resuscitation + broad-spectrum IV antibiotics
         ↓
Surgical exploration (do not delay for imaging)
         ↓
Radical debridement → intraoperative cultures → wound pack
         ↓
ICU: haemodynamic support, nutritional support, DVT prophylaxis
         ↓
Return to theatre in 12-24 hours → repeat debridement
         ↓
Once clean wound: VAC therapy → skin grafting/flap reconstruction
         ↓
HBOT (if available + patient stable); consider IVIG for GAS-NF

Key Recent References

• 2025 Chinese Expert Consensus on Diagnosis and Treatment of Adult NF - most recent consensus document
• McDermott J et al. Necrotizing Soft Tissue Infections: A Review. JAMA Surgery, 2024 - PMID 39259555
• Allaw F et al. Necrotizing fasciitis: an update on epidemiology, diagnostic methods, and treatment. Curr Opin Infect Dis, 2024 - PMID 38037890
• Guliyeva G et al. Practical Review of Necrotizing Fasciitis: Principles and Evidence-based Management. Plast Reconstr Surg Glob Open, 2024 - PMID 38250213
• Bailey and Love's Short Practice of Surgery, 28th Ed. - Chapter 33 & 45