Advantages of New Preoperative Fasting Guidelines for Surgery

It is common practise to have patients fast for an extended period of time before to elective surgery in order to lower stomach volume and acidity, avoid vomiting during anaesthesia, and minimise the risk of aspiration pneumonia. Traditional fasting and abstinence-only regimens (fasting for 8–12 hours and abstaining from alcohol for 4–6 hours) have an effect on the body's metabolism. The American Society of Anesthesiology (ASA) and the Enhanced Recovery After Surgery (ERAS) updated their preoperative fasting recommendations in 1999 and 2012, respectively, to reduce the amount of time spent fasting and not drinking prior to surgery. According to the new index, patients scheduled for elective surgery may ingest sugar-free clear liquids such as tea, water, or juice two hours before to operation. Additionally, patients may consume readily digested items such as milk and bread six hours before to surgery and may eat regularly eight hours prior to surgery. While the American Association of Anesthesiologists' new recommendations clearly minimise the amount of time spent fasting and abstaining from alcohol, their clinical usefulness and safety must be validated. A meta-analysis of randomised controlled trials (RCTs) employing both new and classic methods was recently published in order to offer an evidence-based basis for elective surgery.

PubMed, EBSCO, MEDLINE, Science Direct, Cochrane Library, CNKI, China Biomedical Resources Database, Wanfang Database, Weipu, and the Western Biomedical Journal Literature Database were used to search for publications. Authors chose RCTs that examined the effects of fasting before to surgery during the screening period. Elective surgery, preoperative, fasting and no drinking, patient comfort, thirst, hunger, collapse, hypoglycemia, preoperative gastric volume, preoperative gastric juice pH, and intraoperative stomach volume were among the Chinese and English search terms. To assess the quality of included documents, the RevMan 5.3 software offered by the Cochrane cooperation network was employed. Two independent specialists examined the literature, gathered data, and assessed the possibility of bias.

Six studies were included. Hunger was substantially more prevalent in experimental patients receiving elective surgery than in control patients [Z=3.90; relative risk (RR) =0.58; 95 percent confidence interval (CI): 0.44, 0.76; P0.0001]. Thirst was substantially more prevalent in the experimental group than in the control group (Z=7.22; RR =0.21; 95% CI: 0.13, 0.32; P0.00001).

For patients, surgery, regardless of its size or complexity, results in some degree of trauma. Prolonged fasting and abstinence from alcohol may create an imbalance in the patient's internal milieu, manifested mostly by reduced insulin secretion and elevated growth hormone and glucagon levels, resulting in an imbalance in the body's glucose metabolism. Additionally, people who have surgery acquire insulin resistance. Fasting for an extended period of time before to surgery may easily exacerbate postoperative insulin resistance, impairing the body's capacity to fight infection and interfering with tissue regeneration and wound healing. The meta-analysis indicated that the new recommendations may greatly decrease patients' hunger and thirst, enhance their satisfaction after surgery, and are therapeutically applicable.

For further reading -

He Y, Wang R, Wang F, Chen L, Shang T, Zheng L. The clinical effect and safety of new preoperative fasting time guidelines for elective surgery: a systematic review and meta-analysis. Gland Surg 2022;11(3):563-575. doi: 10.21037/gs-22-4