Nutritional Status Based on Body Mass Index Is Associated With Morbidity and Mortality in Mechanically Ventilated Critically Ill Children in the PICU*

Objective: To determine the influence of admission anthropometry on clinical outcomes in mechanically ventilated children in the PICU. Design: Data from two multicenter cohort studies were compiled to examine the unique contribution of nutritional status, defined by body mass index z score, to 60-day mortality, hospital-acquired infections, length of hospital stay, and ventilator-free days, using multivariate analysis. Setting: Ninety PICUs from 16 countries with eight or more beds. Patients: Children aged 1 month to 18 years, admitted to each participating PICU and requiring mechanical ventilation for more than 48 hours. Measurements and Main Results: Data from 1,622 eligible patients, 54.8% men and mean (sd) age 4.5 years (5.1), were analyzed. Subjects were classified as underweight (17.9%), normal weight (54.2%), overweight (14.5%), and obese (13.4%) based on body mass index z score at admission. After adjusting for severity of illness and site, the odds of 60-day mortality were higher in underweight (odds ratio, 1.53; p < 0.001) children. The odds of hospital-acquired infections were higher in underweight (odds ratio, 1.88; p = 0.008) and obese (odds ratio, 1.64; p < 0.001) children. Hazard ratios for hospital discharge were lower among underweight (hazard ratio, 0.71; p < 0.001) and obese (hazard ratio, 0.82; p = 0.04) children. Underweight was associated with 1.3 (p = 0.001) and 1.6 (p < 0.001) fewer ventilator-free days than normal weight and overweight, respectively. Conclusions: Malnutrition is prevalent in mechanically ventilated children on admission to PICUs worldwide. Classification as underweight or obese was associated with higher risk of hospital-acquired infections and lower likelihood of hospital discharge. Underweight children had a higher risk of mortality and fewer ventilator-free days.