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Abstract

Introduction: To estimate the relation between BMI (Body Mass Index) with length of stay in the ICU and hospital. Methods: Patients admitted between Jan, 2012 and July, 2013 were included and data was assessed for retrospective analysis. A total of 878 patients were included and the variables collected included age, gender, APS (acute physiology score), predicted ICU length of stay (PIS) and predicted hospital length of stay (PHS), predicted mortality, actual ICU stay(AIS) and actual hospital stay (AHS), and actual mortality in context of BMI. World Health Organization classification of BMI for obesity was used for the study. Data was extracted through the APACHE- IV scoring system. We used analysis of variance and logistic regression analysis with SPSS version 22 (SPSS, Chicago, IL). Results: Increase in APS was found with increase in BMI but surprisingly the correlation was not found to be statistically significant. Mean ICU stay was 4.85, 5.21, 5.34, 6.20, 6.96 days for normal BMI, overweight, obesity class I, II, and III respectively. Both PIS and AIS correlated with increase in BMI in linear fashion (P < 0.01). Similarly, both PHS and AHS correlated with increase in BMI in linear fashion (P < 0.01). Surprisingly, no significant correlation was found between BMI and predicted ICU mortality or actual ICU mortality. Likewise, no significant correlation was found between age and gender of patients with ICU and hospital length of stay. Conclusions: BMI is related linearly with the ICU and hospital length of stay which could be explained by various comorbid conditions associated with obesity. However, absence of statistically significant correlation between increasing BMI with APS and ICU mortality was surprising, but supports the findings of previously published studies. Various theories have been proposed for this obesity paradox; for instance high level of anti-inflammatory cytokines, better nutritional reserve, and effective adrenal steroid synthesis in the critically ill obese population. It would seem, however, that obesity is an independent predictor of the ICU duration, and that should be factored into current reimbursement equations in our evolving health care environment.