Calorie intake of enteral nutrition and clinical outcomes in acutely critically ill patients: a meta-analysis of randomized controlled trials

Background: The appropriate calorie intake to be provided to critically ill patients via enteral nutrition (EN) remains unclear. We performed a meta-analysis of randomized controlled trials to compare the effect of initial underfeeding and full feeding in acutely critically ill patients.

Materials and methods: We searched the Medline, EMBASE, and Cochrane Central Register of Controlled Trials databases to identify randomized controlled trials that compared underfeeding with full feeding in critically ill patients. The primary outcome was overall mortality. The secondary outcomes included length of hospital stay, length of intensive care unit (ICU) stay, duration of mechanical ventilation, incidence of pneumonia, Clostridium difficile colitis, other infectious complications, and gastrointestinal intolerance.

Results: In total, 4 studies were included in this meta-analysis. There was no significant difference in overall mortality between the underfeeding and full-feeding groups (odds ratio [OR], 0.94; 95% confidence interval [CI], 0.74-1.19; I (2) = 26.6%; P = .61). Subgroup analysis of the underfeeding subgroup that was fed ≥33.3% of the standard caloric requirement indicated that overall mortality was significantly lower in this underfeeding subgroup than in the full-feeding group (OR, 0.63; 95% CI, 0.40-1.00; I (2) = 0%; P = .05). In contrast, no difference in overall mortality was noted between the underfeeding subgroup that was fed <33.3% of the standard caloric requirement and the full-feeding group. The length of hospital stay and length of ICU stay did not differ between the 2 groups. Moreover, no differences in other secondary clinical outcomes were noted.

Conclusions: None of the analyzed clinical outcomes for the acutely critically ill patients were significantly influenced by the calorie intake of the initial EN.