Pregnancy and Labor Epidural Effects on Gastric Emptying: A Prospective Comparative Study

Abstract

(Anesthesiology. 2022;136:542–550)

Strict fasting during labor has been practiced for more than 70 years in the United States. During that time, the incidence of peripartum aspiration pneumonia has significantly decreased, in part due to advances in anesthesia. Some European guidelines allow patients to consume low-residue food during labor, while US guidelines only allow for clear fluids. There is a lack of strong data concerning gastric emptying in labor. This study compared gastric emptying after a light meal in laboring patients with epidural analgesia, laboring patients without epidural analgesia, pregnant nonlaboring women, and nonpregnant women.

This was a prospective study conducted from May 17, 2018 until November 13, 2020. The study cohort included patients (laboring with epidural, laboring without epidural), and volunteers (pregnant nonlaboring women and nonpregnant women). Participants were all 40 years of age or younger, and all fasted from solid food for 6 hours and from clear liquids for 1 hour. Laboring participants had to be at >38 weeks’ gestation to be included in the study. Patients were excluded if they had a history of esophageal, duodenal, or gastric disorders. A mixture of 1 mg/mL ropivacaine and 0.25 μg/mL sufentanil was used for epidural analgesia. The analgesia administration protocol was as follows: initial bolus of 12 mL, continuous epidural infusion of 3 mL/h with 5-mL patient-controlled boluses (with a 15-min lock-out). An ultrasound examination with an abdominal probe was used to assess gastric contents at 15, 60, 90, and 120 minutes after eating. After the initial ultrasound confirming an empty stomach, participants consumed a light meal of yogurt (125 g, 120 kcal) in 5 minutes. Patients receiving epidural analgesia ingested the meal within an hour of epidural induction. The fraction of gastric emptying 90 minutes after eating was calculated.

A total of 40 patients, 10 in each group, were included in the study and in the analysis. At 90 minutes, the gastric emptying fraction in nonpregnant women was 52% (interquartile range 46 to 61); for nonlaboring pregnant women, 45% (31 to 56); for parturients without epidural analgesia, 7% (5 to 10); and for parturients with epidural analgesia, 31% (17 to 39) (P<0.0001). Laboring women receiving an epidural had a significantly lower fraction of gastric emptying at 90 minutes than the nonpregnant and nonlaboring pregnant groups. However, the group of laboring women who did not receive an epidural had a significantly lower fraction of gastric emptying at 90 minutes than those who did receive an epidural.

While laboring patients had delayed gastric emptying following a small meal, epidural analgesia improved gastric emptying rather than further delaying it.

Editorial to accompany article by Bouvet et al above