Preoperative carbohydrate loading reduces length of hospital stay compared to fasting in patients undergoing major elective, non-cardiac surgery: A systematic Review and Meta- Analysis

Abstract

Introduction 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. Methods Our systematic search was conducted on 15th of October 2021 in five databases, Medline, Embase, Central, Web of Science and Scopus. We included randomized controlled trials that compared the carbohydrate loading (CHO-group) with fasting (Fasting-group) and with placebo (Placebo-group). Main outcomes were length of hospital stay (LOS), postoperative glucose levels on postoperative day 1 and 2, postoperative insulin levels on postoperative day 1, and C-reactive protein (CRP) levels on postoperative day 1. Results Our search revealed 55 eligible articles for the data extraction. LOS was almost two days shorter in the CHO-group as compared to the Fasting-group (MD: -1,71 [95% CI: -3.04, -0,38] days), but there was no significant result when compared to the Placebo-group (-0.01 [-0.16; 0.16]). There were no significant differences between the CHO-group and Fasting-group and CHO-group and Placebo-group regarding the postoperative glucose, insulin and CRP levels. Conclusion This meta-analysis found that preoperative CHO-loading as compared to preoperative fasting 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 fluid intake with CHO-loading could be beneficial in this patient population.