The Gastric Contents Of Pregnant And Parturient Women During Perioperative Period Were Observed Under Different Body Positions And The Related Factors Affecting Gastric Volume Were Discussed

Objective:Through the ultrasound examination of the gastric antrum in patients with full-term pregnancy and scheduled for cesarean section,the consistency of the transverse area of the gastric antrum（CSA）under the supine position and the right decubitus position was compared,and the relationship between the CSA of the gastric antrum and the characteristics of the subjects was discussed to observe the incidence of nausea and vomiting in the patients during the operation.Methods:Pregnant women preparing for cesarean section were selected to fasting according to the standard before the operation,and standardized ultrasound examination was performed on their gastric antrum after entering the operating room.Both the supine and right decubitus positions were evaluated qualitatively and quantitatively.Perlas classification method was used for gastric antrum classification,and the transverse area of gastric antrum（CSA）was formulated as follows:transverse area of gastric antrum（CSA）=（AP×CC×π）/4（AP,anterior and posterior axis diameter;CC,head to tail diameter）to calculate.Univariate correlation analysis was used to evaluate the relationship between CSA in the right lateral gastric antrum and subjects’characteristics.Subarachnoid block anesthesia was performed in L_3-4or L_2-3space,with 3ml of ropivacaine of 0.67%,and the anesthesia level was controlled below T₆.The occurrence of nausea and vomiting in the patients during the operation was observed.Results:There was no statistical difference between the two examination positions of sinus CSA when the Perlas grading of gastric antrum was 0 and 2 points.When the Perlas grading of gastric antrum was 1 point,the CSA of gastric antrum in the right decubi position was significantly greater than that in the supine position.Univariate correlation analysis showed that CSA in the right decubitus gastric antrum was positively correlated with age,body weight,and body mass index（BMI）,but not with gestational age.The incidence of intraoperative nausea and vomiting in the three Perlas scales was 5%,28%,and 50%,respectively.Conclusion:Compared with the two positions,the right decubitus position is more suitable for the ultrasound examination of the gastric antrum.Antrum CSA was positively correlated with age,body weight,and body mass index（BMI）of the subjects,but not with gestational age.