03.18 High Stakes Venous Thromboembolism in Patients with Necrotizing Fasciitis

L. M. Adams1, T. W. Costantini1, N. Neel1, A. E. Berndtson1, J. J. Doucet1, L. N. Godat1  1University Of California – San Diego, Division Of Trauma, Surgical Critical Care, Burns And Acute Care Surgery – Department Of Surgery, San Diego, CA, USA

Introduction: Surgical patients with acute and critical illness have an increased risk of venous thromboembolism (VTE). Trauma patients have high rates of VTE (7-9%) and are started on aggressive prophylaxis with twice daily enoxaparin administration and weight-based dosing; however, the optimal pharmacologic prophylaxis regimen in the emergency general surgery (EGS) patient has not been clearly defined. Patients with necrotizing fasciitis (NF) represent a group of EGS patients who typically present with severe illness associated with tissue injury and a heightened inflammatory state putting them at high risk for VTE. A better understanding of VTE risk for patients with NF is needed to guide clinical care. We hypothesize that the rates of VTE in patients admitted with NF will be high.

Methods: A retrospective review of the National Inpatient Sample database for the years 2017 & 2018 was performed for all patients >18 years old and admitted with an ICD10 diagnosis code for NF. Each admission was assessed VTE based on ICD10 codes for acute deep vein thrombosis and/or acute pulmonary embolism (PE). In addition, all patients were analyzed for surgical excision during hospitalization based on the ICD10 procedure codes for excision of skin, subcutaneous tissue, muscle, or fascia; those who didn’t have surgical excision were excluded from the analysis. For each patient we also obtained their age, sex, race, length of stay (LOS), insurance payer, hospital type, and mortality.

Results: There were 5168 patients admitted over the 2-year period with a diagnosis of NF. Of these patients 3280 (63.5%) were treated with surgical excision. For patients with NF treated with surgical excision, the mean age was 50.314.1 and 42.3% were female.

The overall VTE rate for patients treated with surgical excision was 3.1%; while 21.8% of these were an acute PE. In patients with VTE the LOS was significantly longer with a mean of 28.8 days (95%CI 24.0-33.7days) and in those without VTE 13.8 days (95%CI 13.3-14.3 days), p<0.001. The overall mortality rate for NF patients who underwent surgery was 13.5%; those with VTE had a significantly higher mortality rate at 30.7% (p<0.001).

Conclusion: Though the rate of VTE in patients with NF was low, the associated risk of PE and mortality was unexpectedly high. Further investigations with expanded clinical data are needed to better understand the risk of VTE in patients with NF. Close attention should be paid to ensuring timely VTE prophylaxis is administered, and high intensity regimens should be considered in these high-risk patients.