目的:探讨胃窦超声检查对剖宫产术前2小时口服300mL碳水化合物后胃排空的影响。并分析孕妇胃排空的危险因素。
方法:从2020年8月到2021年2月,共有80名患者,22-43岁,体重指数(BMI)<35kg/m2,胎龄≥36周,进入美国麻醉医师协会(ASA)的身体状况Ⅰ或Ⅱ,研究对象为北京大学国际医院剖宫产,分为干预组(n=40)和对照组(n=40).在干预组中,22:00后限制固体食物,要求患者在剖宫产前两小时服用300mL碳水化合物。在对照组中,手术前一天晚上22:00后,固体食物和液体摄入受到限制。所有患者均采用视觉模拟评分法(VAS)评估术前口渴感和饥饿感。麻醉前以仰卧位和右仰卧位测量胃窦横截面积(CSA),进一步计算两组的胃体积(GV)和胃体积/体重(GV/W)。Perlas在每个患者中进行半定量分级评估。入院时(T0)记录血压和心率,麻醉后5分钟(T1),胎儿分娩后立即(T2)和手术结束时(T3)。记录术中及术后24h恶心呕吐的发生情况。
结果:每组均排除一例,因为在超声评估期间未明确确定胃窦。在半坐姿,干预组的CSA为(5.07±1.73)cm2。对照组(5.24±1.96)cm2,分别;在右侧卧位,干预组CSA为(7.32±2.17)cm2。对照组(7.25±2.24)cm2,GV为(91.74±32.34)mL与(90.07±31.68)mL,GV/W为(1.27±0.40)mL/kgvs.(1.22±0.41)mL/kg,两组间差异无统计学意义(P>0.05)。PerlasA半定量分级在20例患者中显示为0(51.3%),1/16(41%),干预组3人中有2人(7.7%),22人中有0人(56.4%),1/15(38.5%),对照组2/2(5.1%),PerlasA半定量分级的比例两组间差异无统计学意义(P>0.05)。对PerlasA半定量2级患者(干预组3例,对照组2例),麻醉前静脉注射甲氧氯普胺0.2mg/kg。在这项研究中没有观察到误吸病例。干预组口渴、饥饿减少(P<0.05)。两组各时间点血压、心率比较差异无统计学意义(P>0.05)。两组术中低血压发生率比较差异无统计学意义(P>0.05)。两组患者术中、术后恶心发生率差异无统计学意义(P>0.05)。
结论:胃窦超声检查可为孕妇围手术期胃排空功能评估提供客观依据。手术前两小时摄入300毫升碳水化合物,不会增加GV和反流吸入的风险,并且有助于最小化对患者生理状态的干扰,因此导致更好的临床结果。
OBJECTIVE: To investigate the effect of gastric antrum ultrasonography in evaluating gastric emptying after oral administration of 300 mL carbohydrates two hours before cesarean section, and to analyze the risk factors of gastric emptying in pregnant women.
METHODS: From August 2020 to February 2021, a total of 80 patients, aged 22-43 years, body mass index (BMI) < 35 kg/m2, gestational age≥36 weeks, falling into American Society of Anesthesiologists (ASA) physical status Ⅰ or Ⅱ, scheduled for cesarean sections in Peking University International Hospital were recruited and divided into two groups: the intervention group (n=40)and the control group (n=40). In the intervention group, solid food was restricted after 22:00, the patients were required to take 300 mL carbohydrates two hours before cesarean section. In the control group, solid food and liquid intake were restricted after 22:00 the night before surgery. All the patients received assessment of preoperative feeling of thirst and starvation with visual analogue scale (VAS). The cross-sectional area (CSA)of gastric antrum was measured in supine position and right supine position before anesthesia, the gastric volume (GV)and the gastric volume/weight(GV/W)of the two groups was further calculated. Perlas A semi-quantitative grading assessments were performed in each patient. The blood pressure and heart rate were recorded at admission(T0), 5 minutes after anesthesia (T1), immediately after fetal delivery (T2) and at the end of the surgery (T3). The occurrence of nausea and vomiting during the operation and 24 hours after the operation were recorded.
RESULTS: One case in each group was excluded because the antrum was not clearly identified during the ultrasound assessments. In the semi-sitting position, the CSA was (5.07±1.73) cm2 in the intervention group vs. (5.24±1.96) cm2 in the control group, respectively; in the right lateral decubitus position, CSA was (7.32±2.17) cm2 in the intervention group vs. (7.25±2.24) cm2 in the control group, GV was (91.74±32.34) mL vs. (90.07±31.68) mL, GV/W was (1.27±0.40) mL/kg vs. (1.22±0.41) mL/kg, respectively; all the above showed no significant difference between the two groups (P > 0.05). Perlas A semi-quantitative grading showed 0 in 20 patients (51.3%), 1 in 16 (41%), 2 in 3 (7.7%)in the intervention group and 0 in 22 (56.4%), 1 in 15 (38.5%), 2 in 2 (5.1%)in the control group, the proportion of Perlas A semi-quantitative grading showed no significant difference between the two groups (P > 0.05). For the patients with Perlas A semi-quantitative grade 2 (3 cases in the intervention group and 2 cases in the control group), metoclopramide 0.2 mg/kg was intravenously injected before anesthesia. No aspiration case was observed in this study. The intervention group was endured less thirst and hunger (P < 0.05). There was no significant difference in blood pressure and heart rate between the two groups at each time point (P > 0.05). There was no significant difference in the incidence of intraoperative hypotension between the two groups (P > 0.05). There was no significant difference in the incidence of nausea intraoperatively and postoperatively between the two groups (P > 0.05).
CONCLUSIONS: Ultrasonography of gastric antrum can provide objective basis for evaluating gastric emptying of pregnant women perioperatively. 300 mL carbohydrates intake two hours before surgery, which does not increase GV and the risk of reflux aspiration, and is helpful in minimizing disturbance to the patient\'s physiological status, therefore leading to better clinical outcome.