Optimal Inspiratory Pressure for Facemask Pressure-controlled Ventilation in Children

Optimal Inspiratory Pressure for Facemask Pressure-controlled Ventilation in Children: Study Using Detection of Gastric Insufflation Using Ultrasonography of the Antrum and Epigastric Auscultation

The purpose of this study is to find an optimal inspiratory pressure to provide adequate tidal volume and prevent gastric insufflation in pediatric patients. The children under 5 years old are randomly assigned to muscle relaxation group and non-relaxation group. For muscle relaxation group, routine anesthesia induction is performed with muscle relaxant and mask ventilation is started by pressure-controlled mechanical ventilation. Gastric auscultation and abdominal ultrasonography are performed simultaneously during mask ventilation to detect inflow of air. Initial inspiratory airway pressure is 10 cmH2O and increased gradually by 2 cmH2O until gastric insufflation is detected by either of two methods. Tracheal intubation is done after detection of gas. For non-relaxation group, mask ventilation is performed in a same manner, without muscle relaxant. After detection of gas by any of the two methods, rocuronium 0.6 mg/kg is administered and tracheal intubation is performed.

The purpose of this study is to find an optimal inspiratory pressure to provide adequate tidal volume and prevent gastric insufflation in pediatric patients. The children under 5 years old are randomly assigned to muscle relaxation group and non-relaxation group. Stratum was constructed based on age and randomization scheme was performed separately within each stratum. Block randomization was done to ensure balance of the age groups. For muscle relaxation group, routine anesthesia induction is performed with muscle relaxant and mask ventilation is started by pressure-controlled mechanical ventilation. Gastric auscultation and abdominal ultrasonography are performed simultaneously during mask ventilation to detect inflow of air. Initial inspiratory airway pressure is 10 cmH2O and increased gradually by 2 cmH2O until gastric insufflation is detected by either of two methods. Tracheal intubation is done after detection of gas. For non-relaxation group, mask ventilation is performed in a same manner, without muscle relaxant. After detection of gas by any of the two methods, rocuronium 0.6 mg/kg is administered and tracheal intubation is performed. Tidal volume and oxygen saturation are recorded during study period.

During induction of anesthesia, mask ventilation by pressure controlled ventilation is performed with after rocuronium administration in children while continuous gastric auscultation and abdominal sonography are performed.

During induction of anesthesia, mask ventilation by pressure controlled ventilation is performed without rocuronium in children while continuous gastric auscultation and abdominal sonography are performed.

Mask ventilation is performed after administration of rocuronium or not. Initial inspiratory pressure is set as 10 cmH2O and increased gradually by 2 cmH2O until gastric insufflation is detected by either of two methods. Tracheal intubation is done after detection of gas.

Rocuronium 0.6 mg/kg is injected before mask ventilation in muscle relaxant group or after finish of study in non-relaxant group.

Difference in the inspiratory pressure that minimized the incidence of gastric insufflation, yet guaranteed a tidal volume of at least 6 ml/kg between the neuromuscular blocker and non-neuromuscular blocker groups. Gastric insufflation was measured using both gastric ultrasonography and epigastric auscultation.

Interval between start of mask ventilation and detection of gastric insufflation, an expected average of 100 sec

Interval between start of mask ventilation and detection of gastric insufflation, an expected average of 100 sec

Inclusion Criteria: Pediatric patients scheduled for elective surgery under general anesthesia BMI < 30 ASA class 1 or 2 Exclusion Criteria: with difficult airway preexisting pulmonary disease upper respiratory tract infection intestinal obstruction with risk of pulmonary aspiration history of stoke or moyamoya disease

Lee JH, Jung H, Kim EH, Song IK, Kim HS, Kim JT. Optimal inspiratory pressure for face mask ventilation in paralyzed and unparalyzed children to prevent gastric insufflation: a prospective, randomized, non-blinded study. Can J Anaesth. 2018 Dec;65(12):1288-1295. doi: 10.1007/s12630-018-1183-2. Epub 2018 Jul 11.