354 Diagnostic Utility of Point-of-Care Ultrasound in the Evaluation of Necrotizing Soft Tissue Infections

Abstract

Necrotizing soft-tissue infections (NSTIs) are potentially life-threatening medical emergencies that require rapid identification and aggressive treatment. Emergency physicians are utilizing point-of-care ultrasound (POCUS) for a wide variety of applications. The objective of this study was to determine the diagnostic utility of POCUS in the evaluation of patients with suspected SSTI in the emergency department (ED). This was a retrospective review of ED patients presenting to an academic center with symptoms suspicious for NSTI and received a POCUS. POCUS findings were collected from ED POCUS archiving database. Medical records were then reviewed for history, physical examination findings, laboratory results, additional diagnostic testing, operative intervention, disposition, and final diagnosis. POCUS findings were compared with LRINEC scores and operative findings. A total of 65 patients (15 females, 50 males; mean age, 55 years +/- 13.6) were included in this study. Patients presented with pain (46/65), swelling (33/65), redness (28/65) and open wound (21/65). Most common symptomatic sites were feet (27%) and upper arm (21%). Nineteen patients reported injection drug use. In triage, 53% patients were tachycardiac and 5 patients were hypotensive. Pain out of proportion was documented in 3 patients. Based on operative findings, 38% (25/65) patients were found to have NSTI. All patients with final diagnosis of NSTI had sonographic findings (hypoechoic fluid tracking along the deep fascial layers, fluid accumulation > 4 mm in depth along the deep fascial layers, air in the soft tissues) indicating NSTI on POCUS. In addition, POCUS demonstrated abscess (28%), cellulitis (62%), pyomyositis (2.9%) and superficial Fasciitis (27%). Subcutaneous gas was noted in 11 patients. Early surgical consultation was obtained in these eleven patients prior to laboratory results and additional imaging studies. Six patients with LRINEC Score < 6 were found to have NSTI and all 6 patients had sonographic findings suggestive of NSTI on POCUS. Only one of these patients had abnormal vital signs in triage. Our study suggests that POCUS can be a useful adjunct in the evaluation of patients with NSTI. Integration of POCUS findings into LRINEC Score could improve risk stratification.