Gastric Insufflation During Positive Pressure Ventilation

Study Overview
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Brief Summary
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Effect of peak inspiratory pressure on the gastric insufflation is evaluated using ultrasonography during face mask ventilation in obese adults. Effect of facial mask holding techniques on the gastric insufflation is also evaluated.

Official Title
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Effect of the Peak Inspiratory Pressure and Facial Mask Holding Techniques on the Gastric Insufflation During Positive Pressure Ventilation With Facemask in Obese Adults

Conditions
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Gastric Insufflation

Intervention / Treatment
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* Diagnostic Test: ultrasound examination of air insufflation in the upper esophageal region and stomach


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with body mass index ≥ 30 kg/m2 who are scheduled for general anesthesia Exclusion Criteria: Risk of delayed gastric emptying or gastroesophageal reflux (gastroesophageal reflux disease, achalasia, history of stomach surgery, gastrointestinal obstruction, uncontrolled DM) Pregnancy Known or predicted difficult airway

Ages Eligible for Study
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Minimum Age: 20 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Non-Randomized
Intervention Model: Sequential Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: C-E Mask ventilation under PIP 10 cmH2O<br>Two-handed C-E technique is performed during face mask ventilation using a mechanical ventilator with a peak inspiratory pressure of 10 cmH2O. | Diagnostic Test: ultrasound examination of air insufflation in the upper esophageal region and stomach<br>* Presence of air insufflation is assessed using ultrasound in the upper esophageal region and stomach during face mask ventilation<br>|
| Experimental: C-E Mask ventilation under PIP 15 cmH2O<br>Two-handed C-E technique is performed during face mask ventilation using a mechanical ventilator with a peak inspiratory pressure of 15 cmH2O. | Diagnostic Test: ultrasound examination of air insufflation in the upper esophageal region and stomach<br>* Presence of air insufflation is assessed using ultrasound in the upper esophageal region and stomach during face mask ventilation<br>|
| Experimental: C-E Mask ventilation under PIP 20 cmH2O<br>Two-handed C-E technique is performed during face mask ventilation using a mechanical ventilator with a peak inspiratory pressure of 20 cmH2O. | Diagnostic Test: ultrasound examination of air insufflation in the upper esophageal region and stomach<br>* Presence of air insufflation is assessed using ultrasound in the upper esophageal region and stomach during face mask ventilation<br>|
| Experimental: V-E Mask ventilation under PIP 10 cmH2O<br>Two-handed V-E technique is performed during face mask ventilation using a mechanical ventilator with a peak inspiratory pressure of 10 cmH2O. | Diagnostic Test: ultrasound examination of air insufflation in the upper esophageal region and stomach<br>* Presence of air insufflation is assessed using ultrasound in the upper esophageal region and stomach during face mask ventilation<br>|
| Experimental: V-E Mask ventilation under PIP 15 cmH2O<br>Two-handed V-E technique is performed during face mask ventilation using a mechanical ventilator with a peak inspiratory pressure of 15 cmH2O. | Diagnostic Test: ultrasound examination of air insufflation in the upper esophageal region and stomach<br>* Presence of air insufflation is assessed using ultrasound in the upper esophageal region and stomach during face mask ventilation<br>|
| Experimental: V-E Mask ventilation under PIP 20 cmH2O<br>Two-handed V-E technique is performed during face mask ventilation using a mechanical ventilator with a peak inspiratory pressure of 20 cmH2O. | Diagnostic Test: ultrasound examination of air insufflation in the upper esophageal region and stomach<br>* Presence of air insufflation is assessed using ultrasound in the upper esophageal region and stomach during face mask ventilation<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Presence of gastric insufflation in the epigastric region | Under ultrasound, air signal is assessed in the epigastric region | During anesthesia induction | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cross-sectional area of the antral cross-sectional area | During ultrasound examination, anterior-posterior diameter and cranio-caudal diameter of the antrum are measured. Cross-sectional area of the gastric antrum is calculated as follows; (AP × CC × π)/4 (AP=antero-posterior diameter and CC=cranio-caudal diameter). | During anesthesia induction | 
| Presence of gastric insufflation in the upper esophageal region | Under ultrasound, air signal is assessed in the upper esophageal region. | During anesthesia induction | 
| Expiratory tidal volume | Expiratory tidal volumes displayed on the monitor of the anesthesia machine are recorded. | During anesthesia induction |