Background: The objective of this study was to determine whether caloric intake independently influences mortality and morbidity of critically ill patients.
Methods: The study was conducted as a nested cohort study within a randomized controlled trial in a tertiary care intensive care unit (ICU). The main exposure in the study was average caloric intake/target for the first 7 ICU days. The primary outcomes were ICU and hospital mortality. Secondary outcomes included ICU-acquired infections, ventilator-associated pneumonia (VAP), duration of mechanical ventilation days, and ICU and hospital length of stay (LOS). The authors divided patients (n = 523) into 3 tertiles according to the percentage of caloric intake/target: tertile I <33.4%, tertile II 33.4%-64.6%, and tertile III >64.6%. To adjust for potentially confounding variables, the authors assessed the association between caloric intake/target and the different outcomes using multivariate logistic regression for categorical outcomes (tertile I was used as reference) and multiple linear regression for continuous outcomes.
Results: Tertile III was associated with higher adjusted hospital mortality, higher risk of ICU-acquired infections, and a trend toward higher VAP rate. Increasing caloric intake was independently associated with a significant increase in duration of mechanical ventilation, ICU LOS, and hospital LOS.
Conclusions: The data demonstrate that near-target caloric intake is associated with significantly increased hospital mortality, ICU-acquired infections, mechanical ventilation duration, and ICU and hospital LOS. Further studies are needed to explore whether reducing caloric intake would improve the outcomes in critically ill patients.