Extreme Obesity and Outcomes in Critically Ill Patients.
Chest. 2011 Aug 4;
Authors: Martino JL, Stapleton RD, Wang M, Day AG, Cahill NE, Dixon AE, Suratt BT, Heyland DK
Abstract BACKGROUND: Recent literature suggests that obese critically ill patients do not have worse outcomes. However, outcomes in extreme obesity (body mass index [BMI] ?40kg/m2) are unclear. We sought to determine the association between extreme obesity and intensive care unit (ICU) outcomes. METHODS: We analyzed data from a multicenter international observational study of ICU nutrition practices that occurred in 355 ICUs in 33 countries during 2007-2009. Included patients were mechanically ventilated adults >18 years who remained in the ICU for >72 hours. Using generalized estimating equations and Cox proportional hazard modeling with clustering by ICU and adjusting for potential confounders, we compared extremely obese to normal weight patients in terms of duration of mechanical ventilation (DMV), ICU length of stay (LOS), hospital LOS, and 60-day mortality. RESULTS: Of the 8813 patients included in this analysis, 3490 were normal weight (BMI 18.5-24.9kg/m2), 348 had BMI 40-49.9kg/m2, 118 had BMI 50-59.9kg/m2, and 58 had BMI?60kg/m2. Unadjusted analyses suggested that extremely obese critically ill patients have improved mortality (odds ratio for death 0.77, 95% CI 0.62-0.94), but this association was not significant after adjustment for confounders. However, an adjusted analysis of survivors found that extremely obese patients have a longer DMV and ICU LOS, with the most obese patients (BMI ?60kg/m2) also having longer hospital LOS. CONCLUSIONS: During critical illness, extreme obesity is not associated with a worse survival advantage compared to normal weight. However, among survivors, BMI?40kg/m2 is associated with longer time on mechanical ventilation and in the ICU. These results may have prognostic implications for obese critically ill patients.
PMID: 21816911 [PubMed - as supplied by publisher]