Ultrasonography to measure gastric content in pregnant and nonpregnant female patients undergoing elective surgery

Background: Pulmonary aspiration in patients undergoing general anesthesia is a significant complication. Adequate fasting periods and an empty stomach preoperatively are crucial for preventing pulmonary aspiration. With limited evidence suggesting no significant difference in gastric emptying times between pregnant and nonpregnant populations, many anesthesiologists still consider pregnant patients to have “full stomachs”, despite the lack of clear guidelines on fasting periods for pregnant women. Methods: Forty-two term pregnant patients and 42 nonpregnant patients were included in the study. Ultrasonography was performed 15 minutes before surgery to measure gastric antrum dimensions, and the stomach contents (empty, liquid, or solid) were recorded. Using the cross-sectional area (CSA), the antrum volume was calculated based on Perlas formula (mL = 27.0 + 14.6 × CSA − 1.28 × age), and differences between the groups were analyzed. Results: Empty stomach (8/42 = 19% versus 34/42 = 81%), liquid content (16/42 = 38% versus 7/42 = 17%), and solid content (18/42 = 43% versus 1/42 = 2%) differed (p < 0.001) between the pregnant and nonpregnant patients. Antrum dimensions and antrum volumes were different as well (p < 0.001). Conclusions: The gastric emptying rate of pregnant patients differs from that of the normal population, which should be considered when evaluating patients on the operating table.

CUS; Pregnancy; Gastric emptying; Fasting

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