Abstract：
BACKGROUND: Practice on fasting prior to extubation in critically ill patients is variable. Efficacy of fasting in reducing gastric volume has not been well established. The primary objective of this study was to assess the effect of 4 h of fasting on prevalence of empty stomach using gastric ultrasonography in critically ill subjects who are fasted for extubation. The secondary objectives were to evaluate the change in gastric volumes during 4 h of fasting and to determine factors associated with empty stomach after fasting.
METHODS: This was a single-center, prospective, observational study on adult ICU subjects who were enterally fed for at least 6 h continuously and mechanically ventilated. Gastric ultrasound was performed immediately prior to commencement of fasting, after 4 h of fasting, and after nasogastric (NG) aspiration after 4 h of fasting. An empty stomach was defined as a gastric volume ≤ 1.5 mL/kg.
RESULTS: Forty subjects were recruited, and 38 (95%) had images suitable for analysis. The prevalence of empty stomach increased after 4 h of fasting (25 [65.8%] vs 31 [81.6%], P = .041) and after 4 h of fasting with NG aspiration (25 [65.8%] vs 34 [89.5%], P = .008). There was a significant difference in median (interquartile range) gastric volume per body weight between before fasting and 4 h after fasting (1.0 [0.5-1.8] mL/kg vs 0.4 [0.2-1.0] mL/kg, P < .001). No patient factors were associated with higher prevalence of empty stomach after 4 h of fasting.
CONCLUSIONS: Most mechanically ventilated subjects had empty stomachs prior to fasting for extubation. Fasting for 4 h further increased the prevalence of empty stomach at extubation to > 80%.
METHODS: This was a single-center, prospective, observational study on adult ICU subjects who were enterally fed for at least 6 h continuously and mechanically ventilated. Gastric ultrasound was performed immediately prior to commencement of fasting, after 4 h of fasting, and after nasogastric (NG) aspiration after 4 h of fasting. An empty stomach was defined as a gastric volume ≤ 1.5 mL/kg.
RESULTS: Forty subjects were recruited, and 38 (95%) had images suitable for analysis. The prevalence of empty stomach increased after 4 h of fasting (25 [65.8%] vs 31 [81.6%], P = .041) and after 4 h of fasting with NG aspiration (25 [65.8%] vs 34 [89.5%], P = .008). There was a significant difference in median (interquartile range) gastric volume per body weight between before fasting and 4 h after fasting (1.0 [0.5-1.8] mL/kg vs 0.4 [0.2-1.0] mL/kg, P < .001). No patient factors were associated with higher prevalence of empty stomach after 4 h of fasting.
CONCLUSIONS: Most mechanically ventilated subjects had empty stomachs prior to fasting for extubation. Fasting for 4 h further increased the prevalence of empty stomach at extubation to > 80%.
摘要：
背景：危重患者拔管前禁食的做法是可变的。禁食在减少胃体积方面的功效尚未得到很好的证实。这项研究的主要目的是使用胃超声检查评估禁食4小时对禁食拔管的危重病患者空腹患病率的影响。次要目标是评估禁食4小时期间胃体积的变化，并确定禁食后与空腹相关的因素。
方法：这是一个单中心，prospective,观察性研究的成人ICU受试者连续肠内喂养至少6小时并进行机械通气。在开始禁食之前立即进行胃超声检查，禁食4小时后，和禁食4小时后的鼻胃（NG）抽吸后。空腹定义为胃体积≤1.5mL/kg。
结果：招募了40名受试者，和38（95％）的图像适合分析。空腹4小时后空腹患病率增加（25[65.8％]vs31[81.6％]，P=.041），并在禁食4小时后进行NG抽吸（25[65.8％]vs34[89.5％]，P=.008）。禁食前和禁食后4小时之间的中位（四分位数范围）胃体积/体重存在显着差异（1.0[0.5-1.8]mL/kgvs0.4[0.2-1.0]mL/kg，P<.001)。禁食4小时后，没有患者因素与空腹患病率较高相关。
结论：大多数机械通气的受试者在禁食拔管前胃排空。禁食4小时后，拔管时空腹的患病率进一步增加至>80％。
方法：这是一个单中心，prospective,观察性研究的成人ICU受试者连续肠内喂养至少6小时并进行机械通气。在开始禁食之前立即进行胃超声检查，禁食4小时后，和禁食4小时后的鼻胃（NG）抽吸后。空腹定义为胃体积≤1.5mL/kg。
结果：招募了40名受试者，和38（95％）的图像适合分析。空腹4小时后空腹患病率增加（25[65.8％]vs31[81.6％]，P=.041），并在禁食4小时后进行NG抽吸（25[65.8％]vs34[89.5％]，P=.008）。禁食前和禁食后4小时之间的中位（四分位数范围）胃体积/体重存在显着差异（1.0[0.5-1.8]mL/kgvs0.4[0.2-1.0]mL/kg，P<.001)。禁食4小时后，没有患者因素与空腹患病率较高相关。
结论：大多数机械通气的受试者在禁食拔管前胃排空。禁食4小时后，拔管时空腹的患病率进一步增加至>80％。
