***TASK***
the task is to simplify the input abstract of a biomedical literature

***INPUT***
the input is the abstract of a biomedical literature

***OUTPUT***
the output is the simplified abstract for the input abstract of a biomedical literature

***DOCUMENTATION***

***EXAMPLES***

Input: This first update of the review identified two additional eligible studies, bringing the total number of included studies to 25 (forty seven randomised controlled comparisons involving 2543 children considered to be at normal risk of regurgitation or aspiration during anaesthesia). Only one incidence of aspiration and regurgitation was reported. Children permitted fluids up to 120 minutes preoperatively were not found to experience higher gastric volumes or lower gastric pH values than those who fasted. The children permitted fluids were less thirsty and hungry, better behaved and more comfortable than those who fasted. Clear fluids preoperatively did not result in a clinically important difference in children's gastric volume or pH. Evidence relating to the preoperative intake of milk was sparse. The volume of fluid permitted during the preoperative period did not appear to impact on children's intraoperative gastric volume or pH contents. There is no evidence that children who are denied oral fluids for more than six hours preoperatively benefit in terms of intraoperative gastric volume and pH compared with children permitted unlimited fluids up to two hours preoperatively. Children permitted fluids have a more comfortable preoperative experience in terms of thirst and hunger. This evidence applies only to children who are considered to be at normal risk of aspiration/regurgitation during anaesthesia.
Output:

However, the review of trials found that drinking clear fluids up to a few hours before surgery did not increase the risk of regurgitation during or after surgery. Indeed there is an added benefit of a more comfortable preoperative experience in terms of thirst and hunger. Some children are considered more likely to regurgitate under anaesthetic, including those who are obese or have stomach disorders. More research is needed to determine whether these children can also safely drink up to a few hours before surgery.