Ultrasound assessment of gastric contents prior to placental delivery: A prospective multicentre cohort study.

Background: There is ongoing debate regarding the optimal general anaesthetic technique for manual removal of the placenta after vaginal delivery. Using ultrasound examination of the gastric antrum, this study aimed to assess the change in gastric contents during vaginal delivery and to determine the prevalence of stomach at risk for pulmonary aspiration in the immediate postpartum period before placental delivery.

Methods: In this prospective multicentre cohort study, antral ultrasonography was performed at full cervical dilatation within the thirty minutes preceding the beginning of expulsive efforts and after vaginal birth, before placental delivery.

Noninvasive ventilation during spontaneous breathing anesthesia: an observational study using electrical impedance tomography.

Study Objective: To assess the effects of noninvasive ventilation (NIV) during spontaneous breathing anesthesia on functional residual capacity and ventilation distribution.

Design: Prospective and observational study.

Setting: Operating room, military teaching hospital.