Does 360 ml of apple juice ingested before elective surgery worsen gastric volume and acidity in patients given acid aspiration prophylaxis?

Study Objective: 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. Design: Randomized, unblinded study. Setting: Main operating room at a U.S. military hospital. Patients: Eighty-three adult inpatients scheduled to receive general anesthesia for elective surgery. Interventions: 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. Measuremnts and Main Results: 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 < 0.05) those in Group 3 (26 ± 4 ml). Gastric pH was significantly higher ( p < 0.001) in Group 1 (5.16 ± 0.69) and Group 2 (5.78 ± 0.43) than in Group 3 (1.97 ± 0.27). Conclusions: 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.