Does body mass index affect infection-related outcomes in the intensive care unit?

Background: Obesity is a worldwide healthcare concern, but its impact on critical care (intensive care unit; ICU) outcomes is not well understood. The general hypothesis is that obesity worsens ICU outcomes, but published reports fail to demonstrate this effect consistently. We hypothesized that increasing BMI would be an independent predictor of higher mortality rates in the surgical/trauma ICU. Methods: Data on patients with infections, defined by U.S. Centers for Disease Control and Prevention criteria, were collected prospectively from a single university surgical/trauma ICU. From 1996 to 2003, 807 such patients had measurable BMIs on admission to the ICU and were divided into underweight (<18.5 kg/m2), normal weight (18.5–24.9 kg/m2), overweight (25.0–29.9 kg/m2), obese (30.0–39.9 kg/m2), and morbidly obese (≥40.0 kg/m2). The primary outcome was in-hospital death. Bivariate and multivariate analyses were performed. Results: In-hospital death was associated with increasing age, increasing average Acut...