Diagnosis of Necrotizing Faciitis with Bedside Ultrasound: the STAFF Exam
A 44-year-old female presented to the emergency department (ED) with a 3-day history of left groin and inner thigh redness, pain, and swelling; associated with fever, chills, and vomiting. The patient was seen the prior day in a local urgent care at which time she was treated with intravenous vancomycin for cellulitis and discharged on oral antibiotics. The patient presented to the ED within 24 hours of discharge from the urgent care. The initial ED vitals revealed an afebrile (36.9ºC), normotensive (126/63) patient with tachycardia (124) and mild tachypnea (22). On physical exam, the patient had left inner thigh and groin induration measuring 12 cm × 12 cm. The patient was morbidly obese with a BMI>45 kg/m2, making crepitus difficult to appreciate on physical exam. Her initial labs were as follows: lactate 3.5 mmol/L, WBC 18.2 × 103 per mm3, hemoglobin 12.3 g/dL, sodium 136 mmol/dL, glucose 225 mg/dL (12.5 mmol/L), and creatinine 1.8 mg/dL (159 μmol/L). This gave her a laboratory risk indicator for necrotizing fasciitis (LRINEC) score of 6, C-reactive protein (CRP) excluded. (CRP was not ordered in the ED). A bedside ultrasound was performed, which showed positive subcutaneous thickening, air, and fascial fluid (STAFF) concerning for necrotizing fasciitis (). The patient’s soft tissue ultrasound findings are significantly different when compared to normal soft tissue ultrasound (). The patient was started on intravenous vancomycin and piperacillin/tazobactam empirically, and surgery was consulted.\nBased on the LRINEC score, ultrasound findings, and physical exam, the patient was taken immediately to the operating room for presumed necrotizing fasciitis and forwent either CT or magnetic resonance imaging (MRI). In the operating room she underwent operative debridement of the left groin and perineum, resulting in excision of 15 cm × 23 cm of tissue with extensive washout. At the close of the surgery the patient was admitted to the surgical intensive care unit post-operatively for septic shock requiring vasopressors and ventilator dependence. The patient underwent repeat washouts with minor debridements daily for 3 days, with lactate normalization and a down-trending WBC to 13.5 × 103 per mm3 on post-operative day 3. She was extubated and transferred to a step-down unit on post-operative day 5, after which plastic surgery was consulted to evaluate for possible skin graft. Over the course of 9 days and 4 additional operative washouts, the patient was deemed to be a poor graft candidate. A wound vacuum-assisted closure (V.A.C.) device was placed, and the patient was transferred to the plastic surgery service on day 9. The decision was made to forgo skin graft during her immediate hospital stay. The patient was fully ambulatory and discharged home with a wound V.A.C. on post-operative day 28. The patient subsequently received a skin graft, and has been recovering well since.