健康志愿者液体胃排空时间：核磁共振法确定

Gastric emptying time for liquids in healthy volunteers： determination by magnetic resonance imaging

目的 采用核磁共振法确定健康志愿者液体胃排空时间,为探讨合理的术前禁饮时间提供参考.方法 选择健康志愿者19名,ASA分级Ⅰ或Ⅱ级,年龄20～ 60岁,性别不限.于试验前1 d 22：00时开始禁饮、禁食,试验当日8：00（T0）时进行MRI检查,记录基础胃内液体容积.口服12.5％碳水化合物溶液（含40 g麦芽糊精和10 g蔗糖）400 ml.于口服溶液后即刻测量胃内液体容积,之后每25 min复测1次,直至胃内液体容积恢复至口服前基础状态或者小于25 ml,分别记录为T25、T50、T75、T100等.将液体容积通过计算机作图,得到胃排空曲线,计算半量胃排空时间和完全胃排空时间.结果 志愿者液体半量胃排空时间（32±12） min,完全胃排空时间（99±22） min.与T0时比较,T25 、T50、T75 、T100时胃内液体容积增多（P＜0.05）,T125、T150和T175时胃内液体容积差异无统计学意义（P＞0.05）.结论 健康志愿者液体胃排空时间约为2h,提示禁饮时间可缩短至麻醉前2h.

Objective To determine the gastric emptying time for liquids in the healthy volunteers by magnetic resonance imaging （MRI） and to provide a reference for reasonable preoperative fasting time.Methods Nineteen healthy volunteers of both sexes,of ASA physical status Ⅰ or Ⅱ,aged 20-60 yr,were enrolled in the study.The volunteers were fasted from the intake of liquids or solids starting from 22：00 the night before the trial,and 12.5% carbohydrate solution 400 ml containing 40 g maltodextrin and 10 g sucrose was given orally.MRI was performed to measure the baseline gastric fluid volume at 8：00 on the day of the trial （T0）.The gastric fluid volume was measured immediately after administration of the oral solution,and then measured every 25 min until the gastric fluid volume was returned to the baseline before administration of the oral solution or to 〈25 ml,and was recorded as T25,T50,T75,T100,et al.The gastric fluid volume was drawn using a computer to obtain the curve for gastric emptying.The gastric half and total emptying time was calculated using the curves.Results The gastric half emptying time was （32± 12） min,and the gastric total emptying time was （99±22） min in the volunteers.Compared with those at Tb,the gastric fluid volume was significantly increased at T25,T50,T75,T100,and no significant change was found in gastric fluid volume at T125,T150and T175.Conclusion After oral intake of liquids,the gastric emptying time is about 2 h,indicating that the preoperative fasting time for liquids can be shortened to 2 h before anesthesia in the healthy volunteers.