Ultrasound assessment of gastric content in the immediate postpartum period: a prospective observational descriptive study.

INTRODUCTION: Pulmonary aspiration of gastric contents in pregnant women undergoing general anesthesia or sedation/analgesia in the peripartum period is a feared complication in obstetric anesthesia. We assessed the changes in antral cross-sectional area (CSA) with ultrasonography in laboring women and in the immediate postpartum period.

PATIENTS AND METHODS: In an observational study in a university-affiliated maternity, gastric ultrasonography examinations were performed in non-consecutive laboring women, after epidural analgesia insertion and after childbirth. Assessment of antral CSA, difficulty of performance on a numerical scale, and factors that could influence gastric content were noted. A cut-off value of 381 mm2 was taken for the diagnosis of empty stomach.

RESULTS: One hundred women were enrolled in the study. Median antral CSA was 469 mm2 [25th-75th] [324-591] after epidural insertion and 427 mm2 [316-574] after delivery. Antral CSA was ≥ 381 mm2 in 59 of 90 women (65%) after epidural insertion vs. 48 of 100 women (48%) after delivery (P = 0.59). Median variation of antral CSA between two measurements was 36 mm2 [-42 to 114]. Gastric ultrasonography was significantly more difficult to perform during labor than immediately post-delivery (median difficulty score 5 [2-7] vs. 2 [1-4], P < 0.0001). No risk factors (pain, anxiety, diabetes, smoking) were significantly associated with the occurrence of full stomach post-delivery.

CONCLUSION: This study demonstrated that 48% of parturients in the immediate postpartum period presented an antral CSA ≥ 381 mm2 , cut-off being accepted for diagnosis of empty stomach and emphasizes the need for re-assessing before any general anesthetic procedure.