Effect of Timing of Pharmaconutrition (Immunonutrition) Administration on Outcomes of Elective Surgery for Gastrointestinal Malignancies: A Systematic Review and Meta-Analysis

Background: Pharmaconutrition has previously been reported in elective surgery to reduce postoperative infective complications and duration of hospital length of stay. Objective: To update previously published meta-analyses and elucidate potential benefits of providing arginine-dominant pharmaconutrition in surgical patients specifically with regard to the timing of administration of pharmaconutrition. Design: Randomized controlled trials comparing the use of pharmaconutrition with standard nutrition in elective adult surgical patients between 1980 and 2011 were identified. The meta-analysis was prepared in accordance with Preferred Reporting of Systematic Reviews and Meta-Analyses (PRISMA) recommendations. Results: Twenty studies yielding 21 sets of data met inclusion criteria. A total of 2005 patients were represented (pharmaconutrition, n = 1010; control, n = 995), in whom pharmaconutrition was provided preoperatively (k = 5), perioperatively (k = 2), or postoperatively (k = 14). No differences were seen in postoperative mortality with the provision of pharmaconutrition irrespective of timing of administration. Statistically significant reductions in infectious complications and length of stay were found with perioperative and postoperative administration. Perioperative administration was also associated with a statistically significant reduction in anastomotic dehiscence, whereas a reduction in noninfective complications was demonstrated with postoperative administration. Preoperative pharmaconutrition demonstrated no notable advantage over standard nutrition provision in any of the clinical outcomes assessed. Conclusions: This meta-analysis highlights the importance of timing as a clinical consideration in the provision of pharmaconutrition in elective gastrointestinal surgical patients and identifies areas where further research is required.