There was no evidence to suggest a shortened fluid fast results in an increased risk of aspiration, regurgitation or related morbidity compared with the standard 'nil by mouth from midnight' fasting policy. Permitting patients to drink water preoperatively resulted in significantly lower gastric volumes. Clinicians should be encouraged to appraise this evidence for themselves and when necessary adjust any remaining standard fasting policies (nil-by-mouth from midnight) for patients that are not considered 'at-risk' during anaesthesia.
Does 360 ml of apple juice ingested before elective surgery worsen gastric volume and acidity in patients given acid aspiration prophylaxis?
To evaluate whether 360 ml of oral clear liquids consumed within 4 hours of elective surgery worsens gastric volume and acidity in patients given acid aspiration prophylaxis.
                Randomized, unblinded study.
                Main operating room at a U.S. military hospital.
                Eighty-three adult inpatients scheduled to receive general anesthesia for elective surgery.
                Nineteen patients (Group 1) were given 150 mg of oral ranitidine (two doses), 10 mg of metoclopramide, and 360 ml of apple juice 3 hours before the scheduled start of surgery. Thirty-four patients (Group 2) fasted before surgery but received acid aspiration prophylaxis identical to that given to Group 1. Twenty-three additional patients (Group 3) received no oral fluids or acid aspiration prophylaxis before surgery.
                The residual gastric volume (RGV) and the pH of Group 1 patients were compared with measurements obtained in the two groups of patients who fasted. RGV measurements in Group 1 (14 +/- 3 ml) were similar to those in Group 2 (11 +/- 2 ml) and were significantly less than (p less than 0.05) those in Group 3 (26 +/- 4 ml). Gastric pH was significantly higher (p less than 0.001) in Group 1 (5.16 +/- 0.69) and Group 2 (5.78 +/- 0.43) than in Group 3 (1.97 +/- 0.27).
                Three hundred and sixty ml of apple juice consumed within 4 hours of elective surgery by patients given ranitidine and metoclopramide did not worsen gastric volume and acidity.