Preoperative carbohydrate loading reduces length of stay after major elective, non-cardiac surgery when compared to fasting : a systematic review and meta-analysis

Preoperative fasting is a worldwide routine even though the most recent Enhanced Recovery After Surgery (ERAS) Guidelines recommend preoperative carbohydrate loading instead of fasting, but with low quality of evidence. Our aim was to compare the effects of preoperative carbohydrate loading to fasting and placebo in patients undergoing elective major non-cardiac surgery under general anaesthesia. Our systematic search was conducted on 15th of October 2021 in five databases, Medline, Embase, Central, Web of Science and Scopus, and updated on November 12th, 2024. We included randomized controlled trials that compared the carbohydrate loading (CHO-group) with fasting or with placebo. Main outcomes were length of hospital stay (LOS), postoperative glucose levels on postoperative, postoperative insulin levels, and C-reactive protein (CRP) levels. Our search revealed 44 eligible articles for data extraction. LOS was shorter in the CHO group as compared to the No-CHO group (MD: - 0.56 [95% CI: - 1.10, - 0.02]). There were no clinically significant differences between the CHO and No-CHO groups regarding the postoperative glucose, insulin and CRP levels. This meta-analysis found that preoperative CHO-loading as compared to preoperative fasting or placebo shortened the length of hospital stay in patients undergoing major elective, non-cardiac surgery. Although several details are still to be unveiled, these data provide further support that preoperative carbohydrate loading could be beneficial in this patient population.