Effect of pregnancy on gastric emptying of fluid: measurement using ultrasound

Objective To evaluate the effect of pregnancy on gastric emptying of fluid using ultrasound. Methods Thirty parturients who were at full term, aged 20-40 yr, of American Society of Anesthesiologists physical status Ⅰ or Ⅱ, were divided into 2 groups (n=15 each) according to the liquid ingested: clear water group (N group) and carbohydrate beverage group (S group). Parturients underwent food fasting ≥8 h and water fasting≥2 h. Parturients ingested clear water 200 ml in N group and carbohydrate beverage 200 ml in S group.The antral cross-sectional area (CSA) was measured in the semi-sitting position using bedside ultrasonography in the fasting state (T0), immediately after ingesting liquids (T1), and at 30, 60 and 120 min after the end of ingesting liquids (T2-4). Gastric emptying was defined as the antral CSA measured less than or equal to the antral CSA at T0. Results The rate of gastric emptying was all 100% at T4 between two groups.Compared with group N, the rate of gastric emptying was significantly decreased at T3 in group S (P<0.05). Conclusion Gastric emptying of fluid is achieved within 2 h after ingesting clean water or carbohydrate beverage in parturients who are at full term, and gastric emptying is delayed after ingesting carbohydrate beverage compared with that after ingesting clean water. Key words: Pregnancy; Solutions; Gastric emptying; Ultrasonography