Early parenteral nutrition alone or accompanying enteral nutrition in critically ill patients: a systematic review and meta-analysis

Background: Although several large-scale clinical trials shave examined the relationship between early parenteral nutrition (ePN) and critically ill patients, a consensus has not been reached. In addition, no meta-analysis in this area has yet been published. The objective of this meta-analysis was to examine the effect of ePN, alone or accompanying enteral nutrition, in critically ill patients. Methods: A meta-analysis was performed to evaluate risk ratios (RR) and mean differences with 95% confidence intervals (CIs) between the ePN and control groups. Subgroup analyses were conducted to evaluate combinations of early enteral nutrition (eEN). Results: Five randomized control trials (RCTs) were included. Compared with controls, ePN had no effect on mortality (RR: 1.05, 95% CI: 0.96, 1.16). Secondary outcomes were variable: compared with the control group, the ePN group required fewer days of ventilation (p=0.007, RR: -0.95, 95% CI: -1.64, -0.27), but a longer hospital stay (p<0.001, RR: 3.76, 95% CI: 2.25, 5.28). Conclusion: Overall, this meta-analysis from RCTs indicates that provision of ePN within 24-48 hours has no benefit on the survival rate in critically ill patients. Thus, provision of ePN in patients is not needed in those who have contraindications to enteral nutrition or can tolerate a low volume of enteral nutrition.