Optimal Inspiratory Pressure for Facemask Pressure-controlled Ventilation in Children

Not Applicable

Completed

Brief Summary: 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.

Detailed Description: 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.

Recruitment & Eligibility

Inclusion Criteria

Exclusion Criteria

Arm && Interventions

Group	Intervention	Description
Neuromuscular blocker	Mask ventilation	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.
Neuromuscular blocker	Rocuronium	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.
Non-neuromuscular blocker	Mask ventilation	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.

Primary Outcome Measures

Name	Time	Method
Inspiratory Pressure That Cause Gastric Insufflation	Interval between start of mask ventilation and detection of gastric insufflation, an expected average of 100 sec	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.

Secondary Outcome Measures

Name	Time	Method
Diagnostic Method That Detects Gastric Insufflation First	Interval between start of mask ventilation and detection of gastric insufflation, an expected average of 100 sec