Necrotizing Soft Tissue Infection Management (IDSA 2014)

Algorithm Steps

1. ▶

   Start

   Suspected Necrotizing Soft Tissue Infection

   Rapidly progressive infection with systemic toxicity

   1. ●

      Action

      Clinical Features Suggestive of NSTI

      High suspicion with any of these

      • Pain out of proportion to exam findings
      • Rapidly spreading erythema/induration
      • Skin necrosis, hemorrhagic bullae
      • Crepitus on palpation (gas in tissues)
      • Systemic toxicity: Fever, tachycardia, hypotension
      • Failure to respond to initial antibiotics
      1. ●

         Action

         Immediate Resuscitation

         Hemodynamic stabilization

         • IV access, fluid resuscitation
         • Vasopressors if septic shock
         • Blood cultures x2
         • Labs: CBC, BMP, lactate, CK, CRP
         • Type and screen for OR
         1. ◆

            Decision

            Imaging Needed?

            DO NOT delay surgery for imaging if high suspicion

            • CT with contrast: Gas in soft tissues, fascial thickening
            • MRI: Most sensitive but time-consuming
            • Plain X-ray: May show gas
            • IMAGING SHOULD NOT DELAY SURGERY
            1. ●

               Action

               EMERGENT Surgical Consultation

               Surgery is the cornerstone of treatment

               • Call surgery IMMEDIATELY - do not delay
               • Surgical exploration is both diagnostic and therapeutic
               • Findings: Dishwater gray necrotic fascia, lack of bleeding
               • Positive finger test: Easy dissection along fascial planes
               1. ●

                  Action

                  Broad-Spectrum Empiric Antibiotics

                  Start immediately, before surgery

                  • Vancomycin 25-30mg/kg IV load, then 15-20mg/kg q8-12h
                  • PLUS Piperacillin-tazobactam 4.5g IV q6h (or Meropenem 1g q8h)
                  • PLUS Clindamycin 900mg IV q8h (toxin suppression)
                  • Alternative: Vancomycin + Ceftriaxone + Metronidazole + Clindamycin
                  1. ◆

                     Decision

                     NSTI Type Classification

                     Based on culture results and clinical context

                     1. ●

                        Action

                        Type I: Polymicrobial

                        Mixed aerobic/anaerobic, often post-surgical or diabetic

                        • Continue broad coverage: Pip-tazo + Vancomycin + Clindamycin
                        • Covers: GNR, anaerobes, GPC
                        • Common in: Diabetes, peripheral vascular disease, post-op
                        • Fournier's gangrene typically Type I
                        1. ●

                           Action

                           Aggressive Surgical Debridement

                           Repeat until margins clear

                           • Wide excision of all necrotic tissue
                           • Return to OR q24-48h for re-exploration
                           • Until healthy bleeding tissue margins
                           • May require fasciotomy, amputation in severe cases
                           • Wound VAC therapy between debridements
                           1. ●

                              Action

                              ICU Level Care

                              Ongoing critical care support

                              • Hemodynamic monitoring and support
                              • Nutrition: High protein, enteral preferred
                              • Wound care team involvement
                              • Daily reassessment for further debridement
                              • Pain management
                              1. ●

                                 Action

                                 Adjunctive Therapies

                                 Consider in select cases

                                 • IVIG: For streptococcal TSS (controversial)
                                 • Hyperbaric oxygen: For clostridial myonecrosis
                                 • Negative pressure wound therapy
                                 • Reconstructive surgery after infection controlled
                              2. ✓

                                 Outcome

                                 Survival

                                 Infection controlled, wound healing

                                 • Mortality: 20-40% despite optimal treatment
                                 • Earlier surgery = better outcomes
                                 • Reconstructive surgery for wound closure
                                 • Physical rehabilitation
                              3. ⚠

                                 Warning

                                 Poor Prognosis

                                 Delayed diagnosis, extensive disease

                                 • Risk factors for death: Delayed surgery >24h, septic shock, diabetes, immunosuppression
                                 • Truncal involvement worse than extremities
                                 • Age >60 associated with higher mortality
                     2. ●

                        Action

                        Type II: Monomicrobial (GAS)

                        Group A Streptococcus - most common cause

                        • Penicillin G 4 million units IV q4h
                        • PLUS Clindamycin 900mg IV q8h (suppresses toxin production)
                        • Can narrow from empiric therapy once culture confirmed
                        • Consider IVIG 1g/kg day 1, then 0.5g/kg days 2-3
                     3. ●

                        Action

                        Type III: Clostridial (Gas Gangrene)

                        Clostridium perfringens/septicum

                        • Penicillin G 4 million units IV q4h
                        • PLUS Clindamycin 900mg IV q8h
                        • Consider hyperbaric oxygen therapy (if available)
                        • C. septicum: Consider occult GI malignancy