Obesity Is Not Associated With Increased Mortality and Morbidity in Critically Ill Children

Abstract

To evaluate the effect of obesity on mortality, length of mechanical ventilation, and length of stay (LOS) in critically ill children. Retrospective cohort study in 2- to 18-year-olds, admitted to the pediatric intensive care unit (PICU) at the Children's Hospital of Wisconsin from 2005-2009 who required invasive ventilation. Weight z score was used to categorize patients as normal (-1.89 to 1.04), overweight (1.05-1.65), obese (1.66-2.33), and severely obese (>2.33). Underweight patients were excluded. Age, gender, admission type, Pediatric Index of Mortality 2 score, operative status, trauma status, admission Pediatric Outcome Performance Category, and diagnosis categories were also collected. The outcomes were mortality, total ventilator days, and PICU LOS. Univariate analysis was used to compare the groups, and multivariate logistic regression was used to compare mortality. Total ventilation days and LOS were modeled with linear regression. In total, 1030 patients were included in the study, with 753 normal weight, 137 overweight, 76 obese, and 64 severely obese. The risk-adjusted mortality rates in overweight (odds ratio [OR], 1.06; 95% confidence interval [CI], 0.62-1.82), obese (OR, 0.68; 95% CI, 0.31-1.48), and severely obese patients (OR, 1.02; 95% CI, 0.45-2.34) were not significantly different compared with the normal-weight group. Total ventilation days (P = .9628) and PICU LOS (P = .8431) were not significantly different between the groups after adjusting for risk factors. Critically ill overweight, obese, and severely obese children who require invasive mechanical ventilation have similar mortality, length of stay in the PICU, and ventilator days as compared with normal-weight children.