Gastric insufflation and surgical view according to mask ventilation method for laparoscopic cholecystectomy: a randomized controlled study

Abstract

Background: Proper mask ventilation is important to prevent air inflow into the stomach during induction of general anesthesia, and it is difficult to send airflow only through the trachea without gastric inflation. Changes in gastric insufflation according to mask ventilation during anesthesia induction were compared.

Methods: In this prospective, randomized, single-blind study, 230 patients were analyzed to a facemask-ventilated group (Ventilation group) or no-ventilation group (Apnea group) during anesthesia induction. After loss of consciousness, pressure-controlled ventilation at an inspiratory pressure of 15 cmH2O was performed for two minutes with a two-handed mask-hold technique for Ventilation group. For Apnea group, only the facemask was fitted to the face for one minute with no ventilation. Next, endotracheal intubation was performed. The gastric cross-sectional area (CSA, cm²) was measured using ultrasound before and after induction. After pneumoperitoneum with carbon dioxide, gastric insufflation of the surgical view was graded by the surgeon for each group.

Results: Increase of postinduction antral CSA on ultrasound were not significantly different between Ventilation group and Apnea group (0.04 ± 0.3 and 0.02 ± 0.28, p-value = 0.225). Additionally, there were no significant differences between the two groups in surgical grade according to surgeon's judgement.

Conclusions: Pressure-controlled ventilation at an inspiratory pressure of 15 cmH₂O for two minutes did not increase gastric antral CSA and insufflation of stomach by laparoscopic view.

Trial registration: http://cris.nih.go.kr (KCT0003620) on 13/3/2019.

Keywords: Anesthesia induction; Gastric antral cross-sectional area; Gastric insufflation; Gastric ultrasound; Laparoscopy; Rapid sequence induction.

Fig. 1

Example of gastral antrum images on ultrasonography. A, antrum of stomach; L, left lobe of liver; Ao, descending aorta; SMA, superior mesenteric artery; P, pancreas

Fig. 2

Laparoscopic surgical grade of gastric insufflation. (A) Grade 1 = little gastric insufflation. (B) Grade 2 = stomach is expanded beyond the lower left end of the liver, but does not go beyond the round ligament. (C) Grade 3 = stomach is expanded beyond the lower left end of the liver and goes beyond the round ligament. (D) Grade 4 = stomach expands and goes beyond the round ligament, and it is impossible to secure the view around the cystic duct

Fig. 3

Flow diagram of patient selection in this study

Fig. 4

Vital sign changes during anesthesia induction. SpO₂, saturation of percutaneous oxygen; mBP, mean blood pressure; HR, heart rate; PSi, patient state index. Data were analyzed using a repeated measures general linear model. * p < 0.05 compared with Ventilation group; ** p < 0.005 compared with Ventilation group; † p < 0.05 compared with ‘Initial’ in Ventilation group; ‡ p < 0.05 compared with ‘Initial’ in Apnea group