Preoperative Standard Oral Nutrition Supplements vs Immunonutrition: Results of a Systematic Review and Meta-Analysis

Abstract

Multiple studies and meta-analyses have suggested some benefit to immunonutrition (IN) supplements. These studies have often included pre-and post-operative regimens and have utilized inconsistent controls ranging from standard non-supplemented oral diets to high-quality isonitrogenous controls. This study aims to compare outcomes after preoperative nutritional supplementation with IN vs. standard oral nutritional supplements (ONS) or a regular diet without supplements.We performed a systematic literature review. 8 randomized controlled trials (RCTs) of preoperative IN vs. ONS were identified and 9 RCTs of IN vs. no supplements were also identified. Meta-analysis was performed for reported outcomes including wound infection, infectious and non-infectious complications, and length of stay (LOS). The meta-analysis was prepared in accordance with Preferred Reporting of Systematic Reviews and Meta-Analyses (PRISMA) recommendations.We identified 561 patients in 8 RCTs of preoperative IN vs. ONS. 895 patients were identified in 9 RCTs of IN vs. no supplements. When compared to ONS, preoperative IN was not associated with reduced wound infection (OR 0.97, 95% Confidence Interval (CI) 0.45 to 2.11), all infectious complications (OR 0.71, 95% CI 0.30 to 1.68), non-infectious complications (OR 1.25, 95% CI 0.64 to 2.43), or LOS (mean difference 0.07 days, 95% CI À2.29 to 2.43). In RCTs controlled with non-supplemented standard diets, preoperative IN was associated with decreased infectious complications (OR 0.49, 95% CI 0.30 to 0.83, p 0.01) and LOS (mean difference À2.22 days, 95% CI À2.99 to À1.45, p 0.01).In conclusion, there was no evidence for IN to be superior to ONS on several key clinical outcomes. Therefore standard ONS may offer an alternative to IN for preoperative nutritional supplementation.

American Society for Enhanced Recovery and Perioperative Quality Initiative Joint Consensus Statement on Nutrition Screening and Therapy Within a Surgical Enhanced Recovery Pathway

“…There was also concern that older studies were not controlled with isocaloric, isonitrogenous formulas. 85 Overall, IMN study sample sizes are smaller, although a number of medium size trials (n = ~200-300) are published. Concerns were raised regarding the level of industry sponsorship …”

Perioperative catabolism

“…112 Another study failed to show the superiority of preoperative immunonutrition over the use of standard oral supplements. 113 In selected surgical cancer populations (head and neck, pancreas), perioperative immunonutrition may be beneficial. [114][115][116] Some methodological problems, encountered in earlier reports, may explain the limited effectiveness of hypocaloric nutritional concepts in surgical patients.…”

Nutritional Status Deteriorates Postoperatively Despite Preoperative Nutritional Support

“…Hence, the benefit of early postoperative nutrition and its influence on nutritional status have been well studied in esophageal cancer patients [17][18][19] . Whether routine postoperative enteral tube feeding is better than early oral alimentation in these patients remains a matter of debate [4,18,20] . Nutritional status can take up to one year postoperatively to recover in gastric cancer patients [21] .…”

“…However, the timing and composition of the nutritional support regimen are still a matter of debate [4] . While there is a consensus that malnourished surgical patients need early nutritional support to counterbalance nutritional deficits most effectively, few data are available on postoperative evolution of nutritional status after timely administered nutritional support programs.…”