Ultrasonographic Screening of Clinically-suspected Necrotizing Fasciitis

OBJECTIVE: To determine the accuracy of ultrasonography for the diagnosis of necrotizing fasciitis. METHODS: This study was a prospective observational review of patients with clinically-suspected necrotizing fasciitis presenting to the emergency department of an urban (Taipei) medical center between October 1996 and May 1998. All patients underwent ultrasonographic examination, with the ultrasonographic diagnosis of necrotizing fasciitis based on the criterion of a diffuse thickening of the subcutaneous tissue accompanied by a layer of fluid accumulation more than 4 millimeters in depth along the deep fascial layer, when compared with the contralateral position on the corresponding normal limb. The final diagnosis of necrotizing fasciitis was determined by pathological findings for patients who underwent fasciotomy or biopsy results for patients managed nonoperatively. RESULTS: Data were collected for 62 patients, of whom 17 (27.4%) were considered to suffer from necrotizing fasciitis. Ultrasonography revealed a sensitivity of 88.2%, a specificity of 93.3%, a positive predictive value of 83.3%, a negative predictive value of 95.4%, and an accuracy of 91.9% as regards the diagnosis of necrotizing fasciitis. CONCLUSIONS: Ultrasonography can provide accurate information for emergency physicians for the diagnosis of necrotizing fasciitis.