Effect of combined parenteral and enteral nutrition for patients with a critical illness: A meta-analysis of randomized controlled trials

BACKGROUND: Whether combined parenteral nutrition (PN) and enteral nutrition (EN) is superior to EN alone remains controversial. OBJECTIVES: This study aimed to evaluate the efficacy and safety of combined PN and EN versus EN alone for critically ill patients based on published randomized controlled trials (RCTs). DATA SOURCES: Studies designed as RCTs evaluating the treatment effectiveness of combined PN and EN versus EN alone for critically ill patients were identified from PubMed, Embase, and the Cochrane Library from inception to April 2019. METHODS: The pooled relative risks and weighted mean differences with corresponding 95% confidence intervals were calculated using the random-effects model. Twelve RCTs recruiting a total of 5609 adults and 1440 children were selected for the final meta-analysis. RESULTS: The summary relative risks indicated that combined PN and EN was not associated with the risk of all-cause mortality, respiratory infection, urinary tract infection, and nutrition-related complications. Moreover, combined PN and EN was associated with longer hospital stay and higher albumin and prealbumin levels compared with EN alone. No significant differences were, however, found between combined PN and EN and EN alone in terms of ventilatory support, intensive care unit stay, and transferrin and C-reactive protein levels. CONCLUSIONS: This study showed that combined PN and EN significantly increased hospital stay duration and albumin and prealbumin levels compared with EN alone for critically ill patients. Large-scale RCTs should be conducted to compare the treatment effectiveness of combined PN and EN versus EN alone for critically ill patients due to a specific cause.