Obesity is an independent risk factor of mortality in severely injured blunt trauma patients

Abstract

Hypothesis: Obesity is associated with increased morbidity and mortality in critically injured blunt trauma patients.

Design: Case-control study of all critically injured blunt trauma patients between January 2002 and December 2002.

Setting: Academic level I trauma center at a county referral hospital.

Patients: Two hundred forty-two consecutive patients admitted to the intensive care unit following blunt trauma. Patients were divided into 2 groups by body mass index. The obese group was defined as having a body mass index of 30 kg/m2 or higher, and the nonobese group was defined as having a body mass index lower than 30 kg/m2.

Main outcome measures: Univariate and multivariate analyses were performed to identify risk factors for mortality. Complications and length of stay were also evaluated.

Results: Of the 242 patients, 63 (26%) were obese, and 179 (74%) were nonobese. The obese and nonobese groups were similar with regard to age (mean +/- SD, 49 +/- 18 years vs 45 +/- 22 years), male sex (63% vs 72%), Glasgow Coma Scale score (mean +/- SD, 11 +/- 5 vs 11 +/- 5), and injury severity score (mean +/- SD, 21 +/- 13 vs 20 +/- 14). The obese group had a higher body mass index (mean +/- SD, 35 +/- 7 vs 24 +/- 3; P<.001). Mechanisms of injury and injury patterns were similar between groups. The obese group had a higher incidence of multiple organ failure (13% vs 3%; P =.02) and mortality (32% vs 16%; P=.008). Obesity was an independent predictor of mortality with an adjusted odds ratio of 5.7 (95% confidence interval, 1.9-19.6; P=.003).

Conclusions: Critically injured obese trauma patients have similar demographics and injury patterns as nonobese patients. Obesity is an independent predictor of mortality following severe blunt trauma.