UNLABELLED: Current guidelines recommend 6-h milk fasting in periprocedural settings
however, recent evidence suggests potential overconservativeness and supports more liberal pediatric fasting protocols. This study assessed the gastric emptying of two different milk quantities in elementary school-age children using gastric ultrasonography. This prospective crossover trial involved 30 healthy children who fasted overnight on two separate occasions within one month, consuming either 5 or 10 mL/kg of milk. Gastric ultrasonography assessed the gastric antrum cross-section area in the right lateral decubitus position at intervals until milk emptying. The time for the gastric antrum to return to baseline and the gastric emptying time was recorded. After consuming 5 mL/kg of milk, the time for the gastric antrum to return to baseline varied from 1.5 to 3.5 h (mean: 2.35 ± 0.56 h
median: 2.50 (2.00-2.63) hours). The gastric emptying time ranged from 1.5 to 4.0 h, with the mean and median time of 2.63 ± 0.54 h and 2.50 (2.50-3.00) hours, respectively. With 10 mL/kg of milk, the time for the gastric antrum to return to baseline ranged from 2.0 to 5.0 h, with a mean of 3.35 ± 0.62 h and a median time of 3.50 (3.00-4.00) hours. The gastric emptying time ranged from 2.0 to 5.0 h with a mean and median time of 3.62 ± 0.61 h and 3.50 (3.38-4.00) hours. Subgroup analysis revealed no significant differences between children of different genders or body mass indexes. CONCLUSION: The gastric return and emptying times are different for both milk quantities, both shorter than the 6-h fasting recommendation, supporting the liberal fasting protocols recommended by the European Society of Anaesthesiology and Intensive Care. CLINICAL TRIALS REGISTRATION: This trial was registered in the Chinese Clinical Trial Registry (Registration number ChiCTR2300077790) on November 20, 2023. WHAT IS KNOWN: • The ESAIC guidelines recommend a 4-h fasting period for milk products in periprocedural settings for children. WHAT IS NEW: • Our research demonstrates that cow's milk is emptied from the stomach within 4 h, supporting the ESAIC recommendations.