Point-of-Care Ultrasound in the Early Diagnosis of Necrotizing Fasciitis

Abstract

The aim: To detect the ultrasonographic signs of necrotizing fasciitis (NF) suitable for its early diagnosis. Materials and methods: Eigty two patients with soft tissue infection, including 14 with necrotizing faciitis, were examined by ultrasonography at the admission. Ultrasonografic features were compared to intraoperative findings by the same surgeon. Results: The thickening of subcutaneous tissue had high sensitivity (100%), but low specificity (5.8%). The hypoechoic and hyperechoic zones had the shape of “cobblestone” with sensitivity – 78.5%, specificity – 33.8%. Higher specificity (69.1%) had sign of “cobblestone separation” on two layers. The presence of fluid above the fascia (sensitivity – 71.4%; specificity – 69.1%), thickening of the fascia (sensitivity – 85.7%; specificity – 58.8%), indistinctness of the fascia edges (sensitivity – 85.7%; specificity – 66.1%) and loss of fascial homogeneity (sensitivity – 71.4%, specificity – 66.1%) were noted in early stages of NF. Advanced cases of NF were accompanied by the dissection of thick¬ened fascia with a strip of fluid (sensitivity – 57.1%, specificity – 92.6%) and accumulation of a fluid under the fascia (sensitivity – 28.5%, specificity – 95.5%). The muscles thickening (sensitivity – 28.5%; specificity – 67.6%), skin thickening (sensitivity – 57.1%; specificity – 58.8%), and loss of the skin’s lower edge clarity (sensitivity – 57.1%; specificity – 63.2%) don’t have diagnostic value without other signs of NF. Conclusions: Point-of-care ultrasonography allows visualization of soft tissue changes that may be hidden in the initial stages of necrotizing fasciitis and should be recommended for implementation as mandatory method of examination in patients with suspected surgical soft tissue infection.