Burn injury outcomes in patients with pre-existing diabetic mellitus: Risk of hospital-acquired infections and inpatient mortality

Abstract

Background: Diabetes mellitus (DM) is a major cause of illness and death in the United States, and diabetic patients are at increased risk for burn injury. We therefore sought to examine the impact of pre-existing DM on the risk of inpatient mortality and hospital acquired infections (HAI) among burn patients.

Methods: Adult patients (≥18 years old) admitted from 2004 to 2013 were analyzed. Weighted Kaplan-Meier survival curves - adjusting for patient demographics, burn mechanism, presence of inhalation injury, total body surface area, additional comorbidities, and differential lengths of stay - were used to estimate the 30-day and 60-day risk of mortality and HAIs.

Results: A total of 5539 adult patients were admitted and included in this study during the study period. 655 (11.8%) had a pre-existing DM. The crude incidence of HAIs and in-hospital mortality for the whole burn cohort was 8.5% (n=378) and 4.4% (n=243), respectively. Diabetic patients were more likely to be older, female, have additional comorbidities, inhalational injury, and contact burns. After adjusting for patient and burn characteristics, the 60-day risk of HAI among patients with DM was significantly higher, compared to non-diabetic patients (RR 2.07, 95% CI 1.28, 6.79). However, no significant difference was seen in the 60-day risk of mortality (RR 1.34, 95% CI 0.44, 3.10).

Conclusions: Pre-existing DM significantly increases the risk of developing an HAI in patients following burn injury, but does not significantly impact the risk of inpatient mortality. Further understanding of the immune modulatory mechanism of burn injury and DM is imperative to better attenuate the acquisition of HAIs.

Keywords: Burns; Diabetes mellitus; Hospital acquired infections; Outcomes.