Sarcopenia Is Associated With Increased Mortality in Patients With Necrotizing Soft Tissue Infections

Necrotizing soft tissue infections (NSTIs) are surgical emergencies associated with high morbidity and mortality. Identifying risk factors for poor outcome is a critical part of preoperative decision-making and counseling. Sarcopenia, the loss of lean muscle mass, has been associated with an increased risk of mortality and can be measured using cross-sectional imaging. Our aim was to determine the impact of sarcopenia on mortality in patients with NSTI. We hypothesized that sarcopenia would be associated with an increased risk of mortality in patients with NSTI.

This is a retrospective cohort study of NSTI patients admitted from 1995 to 2015 to two academic institutions. Operative and pathology reports were reviewed to confirm the diagnosis in all cases. Average bilateral psoas muscle cross-sectional area at L4, normalized for height (Total Psoas Index [TPI]), was calculated using computed tomography (CT). Sarcopenia was defined as TPI in the lowest sex-specific quartile. Primary outcome was in-hospital mortality. Multivariate logistic regression was performed to assess the association between sarcopenia and in-hospital mortality.

There were 115 patients with preoperative imaging, 61% male and a median age of 57 y interquartile range (IQR 46.6-67.0). Overall in-hospital mortality was 12.1%. There was no significant difference in sex, body mass index (BMI), comorbidities and American Society of Anesthesiologists classification (Table 1). After multivariate analysis, sarcopenia was independently associated with increased in-hospital mortality (Odds ratio, 3.5; 95% Confidence Interval [CI], 1.05-11.8).

Sarcopenia is associated with increased risk of in-hospital mortality in patients with NSTIs. Sarcopenia identifies patients with higher likelihood of poor outcomes, which can possibly help surgeons in counseling their patients and families.