[Relationship between intake volume of carbohydrates solution and gastric emptying time in termed parturients]

Objective: To investigate the relationship between intake volume of carbohydrates solution (CHO) and gastric emptying time in termed parturient, thus to optimize fasting time before anesthesia. Methods: This study was a prospective study. From May to July in 2016, a total of 100 termed parturients in Huangyan Hospital of Wenzhou Medical University, were divided into four groups equally by means of random number table: D1 (200 ml), D2 (300 ml), D3 (400 ml) and D4 (500 ml), based on the different intake volume of 12.5% CHO. All the parturients had been fasted preoperatively before the treatment of oral CHO. The cross-sectional area of gastric antrum (CSA) was measured with an ultrasound machine at baseline (T(0)), 3 min (T(1)), 30 min (T(2)), 60 min (T(3)), 90 min (T(4)), 120 min (T(5)) and 150 min (T(6)) after oral CHO, respectively. Gastric emptying in this study is defined as CSA at any time point is equal to or less than that at T(0). Results: Measurement was failed in eight parturients because of poor imaging quality, two each in D1 and D2 group and four in D4 group. The cubic curve was the best model for gastric emptying among several candidate models estimated with SPSS software, with R(2)>0.9 in all groups. Both the cubic curve and Kaplan-Meier curve indicated that gastric emptying time was prolonged as intake volume increased. Gastric emptying times in D1, D2, D3 and D4 were (76.96±17.69), (96.52±20.14), (109.20±14.70) and (122.86±16.17) min respectively, the difference was significant (F=50.471, P<0.001). All parturients in D1, D2 and D3 group had been in the status of gastric emptying 120 min after oral CHO, and all parturients in D4 group had been in the status of gastric emptying either 150 min after oral CHO. Conclusion: Gastric emptying time will be within two hours when 400 ml or less oral CHO is taken by termed parturient, and it will be prolonged as intake volume increases.