The Association Between Nutritional Adequacy and Long-Term Outcomes in Critically Ill Patients Requiring Prolonged Mechanical Ventilation: A Multicenter Cohort Study

Abstract

Objective: To examine the association between short-term nutritional adequacy received while in the ICU and long-term outcomes including 6-month survival and health-related quality of life in critically ill patients requiring prolonged mechanical ventilation.

Design: Retrospective analysis of data prospectively collected in the context of a multicenter randomized controlled trial.

Setting: An international sample of ICUs.

Patients: Adult patients who were mechanically ventilated for more than 8 days in the ICU.

Interventions: None.

Measurements and main results: Nutritional adequacy was obtained from the average proportion of prescribed calories received over the amount prescribed during the first 8 days. Survival status and health-related quality of life as assessed using the Short-Form 36 v2 were obtained at 3- and 6 months post ICU admission. Of the 1,223 patients enrolled in the randomized controlled trial, 475 met the inclusion criteria for this study. At 6-month follow-up, 302 of the 475 patients (64%) were alive. Survival time in those who received low nutritional adequacy was significantly shorter than those who received high nutritional adequacy while adjusting for important covariates (adjusted hazard ratio, 1.7; 95% CI, 1.1-2.6). At 3-month follow-up, a 25% increase in nutritional adequacy was associated with improvements in Physical Functioning and Role Physical of 7.3 (p = 0.02) and 8.3 (p = 0.004) points, respectively. At 6-month follow-up, adjusted increases in Physical Functioning and Role Physical scores for every 25% increase in nutrition adequacy became smaller and were no longer statistically significant (adjusted estimate for Physical Functioning = 4.2, p = 0.14; for Role Physical = 3.2, p = 0.25).

Conclusions: Greater amounts of nutritional intake received during the first week in the ICU were associated with longer survival time and faster physical recovery to 3 months but not 6 months post ICU discharge in critically ill patients requiring prolonged mechanical ventilation. Current recommendations to underfeed critically ill patients may cause harm in some long-stay patients.