Exploration of the Appropriate Combination of Positive End Expiratory Pressure and Tidal Volume Using the Intratidal Compliance Volume Profile in Children

Study Overview
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Brief Summary
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In children under 6 years of age undergoing regular surgery during general anesthesia, the intratidal compliance profile is evaluated when different tidal volumes are applied at different positive end expiratory pressures. Then determine the most appropriate combination of positive end-tidal pressure and tidal volume.

Official Title
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Exploration of the Appropriate Combination of Positive End Expiratory Pressure and Tidal Volume Using the Intratidal Compliance-volume Profile in Children

Conditions
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Respiratory Compliance

Intervention / Treatment
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* Other: Changes in positive end-expiratory pressure and tidal volume


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Children undergoing surgery > 1 hour under general anesthesia Children ≤ 6 years American society of anesthesiology physical status I, II Exclusion Criteria: Previous lung surgery Bronchopulmonary dysplasia, respiratory distress syndrome Other interstitial lung disease Laparoscopic surgery Thoracic surgery, abdominal surgery

Ages Eligible for Study
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Minimum Age: 1 Month
Maximum Age: 6 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: Other
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Evaluation of intratidal compliance<br>When the patient is in the supine position 10 minutes after induction of anesthesia, the following 4 mechanical ventilator settings are applied to the patients in order. Positive end-expiratory pressure 8 cmH2O, tidal volume 8 ml/kg Positive end-expiratory pressure 10 cmH2O, tidal volume 5 ml/kg Positive end-expiratory pressure 10 cmH2O, tidal volume 8 ml/kg Positive end-expiratory pressure 12 cmH2O, tidal volume 5 ml/kg | Other: Changes in positive end-expiratory pressure and tidal volume<br>* When the patient is in the supine position 10 minutes after induction of anesthesia, the following 4 mechanical ventilator settings are applied to the patients in order. Positive end-expiratory pressure 8 cmH2O, tidal volume 8 ml/kg Positive end-expiratory pressure 10 cmH2O, tidal volume 5 ml/kg Positive end-expiratory pressure 10 cmH2O, tidal volume 8 ml/kg Positive end-expiratory pressure 12 cmH2O, tidal volume 5 ml/kg<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Intratidal compliance profiles in each ventilator settings | The investigators will determine Intratidal compliance profile using the changes in compliance over time --> I, merely increasing compliance profile; IH, increasing turning into horizontal compliance profile; D, merely decreasing compliance profile; HD, horizontal turning into decreasing compliance profile; IHD, increasing turning into horizontal and further turning into decreasing compliance profile If compliance profile is I, the PEEP is low. On the other hand, compliance profile is D, PEEP level is considered to be high. | During general anesthesia (up to about 50 min-1 hr after induction of anesthesia) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Respiratory compliance | ml cmH2O-1 | During general anesthesia (up to about 50 min-1 hr after induction of anesthesia) | 
| Driving pressure | cmH2O | During general anesthesia (up to about 50 min-1 hr after induction of anesthesia) | 
| Blood pressure | mmHg | During general anesthesia (up to about 50 min-1 hr after induction of anesthesia) |