儿科手术术前传统的禁食时间为12h,禁饮4h,以防止呕吐、反流及误吸的发生。Robert和Shirley标准认为胃液量≥0.4mg·kg~(-1)、胃液pH≤2.5有发生呕吐、反流及误吸的危险。但近期研究发现术前2～3h给予清亮饮料不增加呕吐发生率。本文应用实时超声波检查技术测量饮用饮料前后的胃窦体积、残余胃液容量,残余胃液pH值,评估术前饮用乳类或清亮饮料后安全的禁食时间。 The traditional fasting time before pediatric surgery was 12h, forbidden to drink for 4h to prevent vomiting, reflux and aspiration. Robert and Shirley standards that the amount of gastric juice ≥ 0.4mg · kg -1, gastric pH ≤ 2.5 are vomiting, reflux and aspiration risk. However, recent studies found that 2 ~ 3h before surgery to give clear drinks do not increase the incidence of vomiting. In this paper, the volume of gastric antrum, the residual gastric juice volume, the residual gastric juice pH value before and after the drinking beverage were measured by real-time ultrasonic inspection technique, and the safe fasted time before drinking the milk or clear beverage was evaluated.