Gastric emptying time of two different quantities of clear fluids in children: A double-blinded randomized controlled study

Background Perioperative pulmonary aspiration risk increases with increased preoperative gastric volume; hence traditionally, healthy children are kept fasted overnight before surgery. Current guidelines recommend 2-hours clear fluids fasting prior to anaesthesia. However, emerging evidence favours allowing 3 mL/kg clear fluids up to 1-hour before anaesthesia. We compared the gastric volume and gastric emptying time after ingestion of 3 mL/kg and 5 mL/kg of clear fluids. Methods The present study enrolled forty-four children, aged between 6 and 14 years. On the day of surgery, baseline gastric volume was estimated using ultrasound and patients were randomly allocated in to two groups of equal number i.e. Group 3 and Group 5 (patients received 3 mL/kg and 5 mL/kg 5% Dextrose respectively). Repeated gastric ultrasound was performed at every five-minutes until the gastric volume reached baseline levels. The primary objective of the study was to compare gastric emptying time. Secondary objectives included comparison of antral cross-sectional area (ACSA) and gastric volume. Results The demographic profile, preoperative fasting duration for clear fluids and baseline gastric volume were comparable between groups. In both groups, compared to baseline the ACSA and gastric volume increased significantly following fluid ingestion and then decreased exponentially to reach baseline within 1-hour. The median (IQR) (range)gastric emptying time (minutes) [35.0 (28.8, 40.0) (20.0 - 45.0) in group 3 and 40.0 (28.8, 45.0) (20.0 -50.0) in group 5] and emptying t1/2 (minutes) [17.0 (15.7, 21.5) (14.4 - 24.0) in group 3 and 18.6 (16.0, 22.0) (15.1 - 23.8) in group 5] were comparable [median difference -5 (95% CI -7.8 to 2.1) and-1.5 (95% CI -2.3 to 1.0) respectively] (p=0.16 and p=0.44 respectively). Conclusion As the gastric volume returned to baseline within 1-hour even after ingesting 5 mL/kg clear fluids, the preoperative fasting time can be reduced to 1-hour and healthy children undergoing elective procedure can be safely allowed to drink up to 5 mL/kg clear fluids.