The Effect of Prolonged Face Mask Ventilation on Gastric Insufflation: A Prospective Observational Study

Background: Pulmonary aspiration is a potentially lethal perioperative complication that can be precipitated by gastric insufflation. Face mask ventilation (FMV), a ubiquitous anesthetic procedure, can cause gastric insufflation. FMV with an inspiratory pressure of 15 cm H(2)0 provides the best balance between adequate pulmonary ventilation anda low probability of gastric insufflation. There is no data about the effects of FMV > 120 seconds. Objectives: To investigate the effect of prolonged FMV on gastric insufflation. Methods: We conducted a prospective observational study at a tertiary medical center with female patients who underwent oocyte retrieval surgery under general anesthesia FMV. Pre- and postoperative gastric ultrasound examinations measured the gastric antral cross-sectional area to detect gastric insufflation. Pressure-controlled FMV with an inspiratory pressure of 15 cm H(2)0 was continued from the anesthesia induction until the end of the surgery. Results: The study comprised 49 patients. Baseline preoperative gastric ultrasound demonstrated optimal and good image quality. All supine measurements were feasible. The median duration of FMV was 13 minutes (interquartile range 9-18). In the postoperative period, gastric insufflation was detected in only 2 of 49 patients (4.1%). There was no association between the duration of FMV and delta gastric antral cross-sectional area (-0.01; 95% confidence interval -0.04 to 0.01, P= 0.31). Conclusions: Pressure-controlled FMV with an inspiratory pressure of 15 cm H(2)0 carries a low incidence of gastric insufflations, not only as a bridge to a definitive airway but as an alternative ventilation method for relatively short procedures in selective populations.