Effectiveness and Safety of Preoperative Oral Carbohydrates in Enhanced Recovery after Surgery Protocols for Patients with Diabetes Mellitus: A Systematic Review.

To evaluate the necessity and safety of preoperative oral carbohydrates in enhanced recovery after surgery (ERAS) protocols for diabetes mellitus patients. We searched PubMed, EMBASE, the Cochrane Library, Chinese Biomedical Literature Database, China National Knowledge Infrastructure, and WANFANG databases for articles published through September 2018. We used the Cochrane risk-of-bias tool to assess the methodological quality of included studies. Literature screening, data extraction, and quality evaluation were performed independently by two investigators. Of the 6328 retrieved articles, five eligible randomized controlled trials were included. Two were from China and three were from Germany, Sweden, and Canada. Preoperative oral carbohydrates may facilitate control of preoperative blood glucose, improve postoperative insulin resistance in diabetes patients, and decrease the occurrence of adverse reactions. However, the overall quality of the included studies was low. The available evidence shows that preoperative oral carbohydrates are probably beneficial for patients with diabetes mellitus. High-quality, large randomized controlled trials are needed to verify our findings and provide quantitative results.