Edited by Laura Lu and Matthew Lindsey - 7/1/2021
Descriptors
Necrotizing soft tissue infection, Necrotizing fasciitis, Flesh Eating Bacteria
Exam Pearls
Differentiate NSTI from garden variety cellulitis or abscess.
Bullae, discoloration, rapid progression, ischemia, and systemic and laboratory abnormalities are indicative of NSTI.
Workup
Radiographs: Orthogonal views of the limb (e.g., order AP and lateral views of limb)
Other imaging:
CT scan in equivocal/early cases, look for subcutaneous emphysema, fascial thickening, and associated abscesses.
MRI in equivocal/early cases (lack of T2 signal in fascia decreases likelihood)
Systemic: Monitor vital signs, q1hr checks, for SIRS/systemic manifestations.
Labs:
Full labs including CBC, BMP, ESR, CRP
LRINEC Score calculator
Other: None
Management
Need for acute intervention: Consults with any possibility of NSTI should be staffed with senior/fellow/attending ASAP.
Weight-bearing and range of motion: Weightbearing as tolerated but avoid dependent positioning and keep limb elevated.
Type of immobilization: Not necessary
Admission or discharge status: Admission to appropriate service, NPO, broad spectrum antibiotics
Anticoagulation: As prior, consider holding if high suspicion
Antibiotics: Immediate broad spectrum after blood cultures drawn.
MRSA-active agent like vancomycin, daptomycin, linezolid or ceftaroline
AND
Broad gram-negative coverage such as piperacillin–tazobactam, ampicillin–sulbactam, ticarcilin-clavulanate, extended-spectrum cephalosporins or carbapenems
AND metronidazole or clindamycin if no anaerobic coverage already
Surgical Indications
Absolute: High Clinical Suspicion and/or High LRINEC score
Relative: Equivocal clinical suspicion
Not an indication: Cellulitis, Rashes, Myositis
References
Anaya DA, Dellinger EP. Necrotizing soft-tissue infection: diagnosis and management. Clin Infect Dis. 2007 Mar 1;44(5):705-10. doi: 10.1086/511638. Epub 2007 Jan 22. PMID: 17278065.
Faraklas I, Yang D, Eggerstedt M, Zhai Y, Liebel P, Graves G, Dissanaike S, Mosier M, Cochran A. A Multi-Center Review of Care Patterns and Outcomes in Necrotizing Soft Tissue Infections. Surg Infect (Larchmt). 2016 Dec;17(6):773-778. doi: 10.1089/sur.2015.238. Epub 2016 Nov 11. PMID: 27834617; PMCID: PMC5124740.
Hua C, Bosc R, Sbidian E, et al. Interventions for necrotizing soft tissue infections in adults. Cochrane Database Syst Rev. 2018;5(5):CD011680. Published 2018 May 31. doi:10.1002/14651858.CD011680.pub2
Bechar J, Sepehripour S, Hardwicke J, Filobbos G. Laboratory risk indicator for necrotising fasciitis (LRINEC) score for the assessment of early necrotising fasciitis: a systematic review of the literature. Ann R Coll Surg Engl. 2017;99(5):341-346. doi:10.1308/rcsann.2017.0053
Bonne SL, Kadri SS. Evaluation and Management of Necrotizing Soft Tissue Infections. Infect Dis Clin North Am. 2017 Sep;31(3):497-511. doi: 10.1016/j.idc.2017.05.011. PMID: 28779832; PMCID: PMC5656282.