Optimal Inspiratory Pressure for Facemask Pressure-controlled Ventilation in Children

Study Overview
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Brief Summary
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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
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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.

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

Conditions
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Child, Anesthesia

Intervention / Treatment
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* Other: Mask ventilation
* Drug: Rocuronium


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 1 Month
Maximum Age: 5 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Neuromuscular blocker<br>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. | Other: Mask ventilation<br>* 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.<br>Drug: Rocuronium<br>* Rocuronium 0.6 mg/kg is injected before mask ventilation in muscle relaxant group or after finish of study in non-relaxant group.<br>|
| Active Comparator: Non-neuromuscular blocker<br>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. | Other: Mask ventilation<br>* 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.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Inspiratory Pressure That Cause Gastric Insufflation | 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 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Diagnostic Method That Detects Gastric Insufflation First |  | Interval between start of mask ventilation and detection of gastric insufflation, an expected average of 100 sec |