Impact of obesity on mortality and complications in trauma patients

To examine the association between obesity and outcomes in injured patients.

The United States is facing an obesity epidemic affecting 1 in 3 adult Americans. Very little is known about the role of obesity in acute illness. Optimal care of obese trauma patients can only be achieved once we gain a better understanding of the impact of severe obesity on trauma outcomes.

We conducted a retrospective cohort study of 147,680 patients admitted to 28 level I and level II Pennsylvania trauma centers between 2000 and 2009. Logistic regression was used to examine the association between obesity and in-hospital mortality and major complications, adjusting for injury severity, age, gender, mechanism of injury, systolic blood pressure, and the motor component of the Glasgow Coma Scale, comorbidities, and year of admission. Patients were grouped into predefined weight categories: underweight (<1st percentile), reference (1st-74th percentile), grade 1 obesity (75th-90th percentile), grade 2 obesity (91th-95th percentile), grade 3 obesity (96th-99th percentile), and grade 4 obesity (>99th percentile). Body mass index was not calculated because height data was not available.

After adjusting for injury severity and other risk factors, male patients with severe obesity-grade 3 obesity [adjusted odds ratio (AOR) 1.28; 95% confidence interval (CI): 1.00, 1.64; P = 0.052] or grade 4 obesity (AOR 2.30; 95% CI: 1.48, 3.58; P < 0.001)-were more likely to die than nonobese patients. Severe obesity was associated with an approximately twofold higher risk of major complications: male patients with grade 3 obesity (AOR 1.71; 95% CI: 1.48, 1.97; P < 0. 001) or grade 4 obesity (AOR 2.14; 95% CI: 1.83, 2.51; P < 0.001). Similar results were obtained for female patients. Male and female patients with severe obesity had a 2.5- to 4-fold higher risk of developing acute renal failure. Severely obese females had 2.5- to 4.5-fold higher risk of developing wound complications, and a 4-to 8-fold higher risk of developing decubiti.

Severely obese trauma patients were at least 30% more likely to die and approximately twice as likely to have a major complication compared with nonobese patients.