Hypoalbuminemia is Not a Predictor of Mortality in Patients with Necrotizing Soft Tissue Infections

Author(s):
Manuel Castillo-Angeles ; Sean Hickey; Mehreen Kisat; Deepika Nehra; Stephanie Nitzschke; Ali Salim; Reza Askari

Background:

Necrotizing soft-tissue infections (NSTIs) are surgical emergencies associated with high morbidity and mortality. Risk factors associated with poor outcomes need to be identified as they play an important role in counseling patients. Emergency patients with hypoalbuminemia are known to have increased mortality. However, no previous studies have assessed the predictive value of low albumin on mortality in patients with NSTIs. We aimed at assessing the predictive power of hypoalbuminemia on in-hospital mortality in a cohort of NSTI patients.

Hypothesis:

We hypothesize that low albumin levels will be associated with an increased risk of mortality in patients with NSTI.

Methods:

This is a retrospective cohort study of NSTI patients admitted from 1995 to 2014 to two urban, tertiary-care, academic hospitals. Operative and pathology reports were reviewed to confirm all cases. Patients were divided into two groups according to their admission plasma albumin levels (<2.7 g/dL=low, >=2.7g/dL=normal). Primary outcome was in-hospital mortality. Multivariate logistic regression was performed to assess the association between albumin levels and in-hospital mortality. For sensitivity analysis, plasma albumin was used as a continuous variable in the model.

Results:

There were 420 patients with available albumin levels, 57.6% males and a median age of 57 years (IQR 46.6–67). 105 (25%) were immunocompromised. Overall in-hospital mortality was 16.9%. There was no significant difference in gender, body mass index (BMI), and comorbidities. Patients with hypoalbuminemia were older (p<0.05). In-hospital mortality rate was similar between patients with low or normal albumin (18.8 vs. 15.0%, p=0.297). After multivariate analysis, albumin levels were not independently associated with increased in-hospital mortality when used as a categorical (Odds ratio [OR], 1.1; 95% Confidence Interval [CI], 0.53-2.13, p=0.84, AUROC 0.83) or continuous variable (OR 0.73, CI 0.44 – 1.21, p=0.23, AUROC 0.83).

Conclusions:

Hypoalbuminemia is not associated with increased risk of in-hospital mortality in patients with Necrotizing soft-tissue infections. Other measures of nutritional status as well as inflammatory markers should be studied to identify NSTI patients with higher likelihood of poor outcomes.0