Necrotizing Soft Tissue Infections (NSTIs)

• NSTIs include a range of conditions characterized by rapid progression, extensive necrosis, and high mortality. NSTIs may involve any layer of the soft tissue compartment including dermis, subcutaneous tissue, superficial/deep fascia or muscle.
• Most commonly a polymicrobial infection with mix of gram-positive cocci, gram-negative rods, and anaerobes.
• Early clinical features include swelling, erythema, pain, sense of heaviness in the affected part, low grade fever, tachycardia; late features include tense edema, pain out of proportion, ecchymosis, blisters/ bullae, necrosis, crepitus, and/ or subcutaneous gas
• Making The Diagnosis
• Maintain a high clinical suspicion and recognize early clinical signs and symptoms
• Consider risk factors: diabetes mellitus, injection drug use, alcoholism, immune suppression, chronic skin infections
• Xray findings may include gas within soft tissue and ultrasound may reveal fluid collections along fascial plane or subcutaneous gas
• Treatment
• Urgent surgical consultation for debridement. May include fasciotomy or amputation.
• Aggressive resuscitation with IV fluids and IV antibiotics: vancomycin 1g Q12 plus meropenam 1g IV Q8. Alternatively, piperacillin/ tazobactam 4.5g IV every 6 hours
• Add clindamycin to inhibit toxin synthesis, which can be critical for controlling the inflammatory response in patients with clostridial or streptococcal infections.
• Tetanus prophylaxis

References

• Anaya DA, Dellinger EP. Necrotizing soft-tissue infection: diagnosis and management. Clin Infect Dis. 2007 Mar 1;44(5):705-10. Epub 2007 Jan 22.
• Kelly EW, Magilner D. Soft Tissue Infections. In: Tintinalli JE, Stapczynski J, Ma O, Yealy DM, Meckler GD, Cline DM. eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 8e New York, NY: McGraw-Hill; 2016.
• Photo credit: https://www.podiatrytoday.com/treating-necrotizing-fasciitis-caused-iser...