Preoperative carbohydrate loading for elective surgery: a systematic review and meta-analysis

Abstract

It is unclear whether the preoperative administration of oral carbohydrates (CHO) is safe and effective, and therefore we herein evaluated the efficacy and adverse events associated with CHO for elective surgery. Comprehensive searches were conducted to identify randomized controlled trials (RCTs), which evaluated preoperative CHO for elective surgery. Two reviewers independently selected the trials, extracted data, and assessed the methodological qualities and evidence levels. The data were analyzed by the RevMan 5.0 software program. CHO increased the insulin and glucose levels on the first day after surgery higher than those in overnight fasting group (fifteen RCTs) and i.v. glucose infusion group (three RCTs). The pooled results of thirteen RCTs showed greater declines in the insulin level at the induction of anesthesia and a smaller increase in the glucose level at the end of surgery, and fewer decreases in the postoperative insulin sensitivity index in the CHO group were observed as compared to the placebo group. No aspiration was observed in any of the included studies. CHO appears to be safe, and may attenuate postoperative insulin resistance as compared to placebo. However, the quality of most of the published trials has been poor, and the evidence levels for most outcomes were low, so rigorous and larger RCTs are needed in the future.