Abstract
Necrotizing Fasciitis (NF) is a life-threatening infectious condition which requires expedient diagnosis to proceed with urgent surgical debridement. However, it can be difficult to establish an early diagnosis and expedite operative management as signs and symptoms are often non-specific and may mimic other pathology. Scoring systems such as The Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) have been proposed to incorporate laboratory findings to predict whether a soft tissue infection is likely to be NF. Recent studies have found the sensitivity and specificity of the LRINEC tool to be lower than originally cited by the LRINEC authors in a validation cohort. Furthermore, there seems to be a predilection for certain geographic locations of patients with NF transferred to our tertiary care center for management, however, to our knowledge, geographic risk factors for NF have not been reported. This study also aims to determine the morbidity and mortality rate of NF at our Canadian tertiary hospital in recent years.
Comorbidities such as smoking, diabetes, and steroid use will be analyzed for any correlation with developing NF. Identification of patient factors in correlation with laboratory values may help identify patients at higher risk for having NF upon their presentation to the emergency department. A resultant earlier diagnosis of necrotizing soft tissue infections would allow for earlier surgical debridement and positively influence patient outcomes.
A retrospective chart review of 125 cases of NF at Kingston Health Sciences Centre from 2005 to 2017 was carried out to assess the validity of the LRINEC in our population and to examine the effect of comorbid factors such as smoking, diabetes, and corticosteroid use on the development of NF. The study cohort included patients treated by all surgical disciplines at our institution over twelve years. A separate cohort of 125 cellulitis or abscess cases was analyzed to assess the validity of the LRINEC tool in differentiating necrotizing fasciitis from non-necrotizing infections such as cellulitis and soft tissue abscess.
The 30-day mortality rate of NF treated at our institution during the study period was 21%. Advanced age was found to be a significant risk factor for death within 30 days of diagnosis (p=0.001). Smoking and steroid use were both found to increase risk for developing NF (p=0.01 and p=0.03, respectively). Diabetes did not appear to increase risk NF. There was no statistical difference in mortality rates between males and females with NF. The sensitivity of LRINEC in detecting NF was only 47% with a specificity of 74%.
The mortality rate of NF at our center is similar to that of other countries in recent years. Males and females have nearly equal mortality rates from NF. Smoking and steroid use appear to increase risk for developing NF, while diabetes may not. The LRINEC assessment tool alone may underestimate risk for developing NF, however, use of other clinical factors such as comorbidity analysis will further aide in the diagnosis of NF allowing for earlier surgical debridement.
