The Influence of LMA Cuff Pressure on Gastric Insufflation Assessed by Ultrasound in Pediatric Patient

Study Overview
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Brief Summary
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Cuff inflation up to the maximum cuff pressure when using LMA flexible can cause sore throat and discomfort after the surgery, and if the surgery is unexpectedly prolonged, there can be a side effect that can cause ischemic damage around the neck. If keeping cuff pressure low will not increase gastric insufflation and there is no change in other outcome variables, keeping it low may have a positive effect on anesthesia management and outcome in children.

Official Title
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The Influence of LMA Cuff Pressure on Oropharyngeal Leak Pressure and Gastric Insufflation Assessed by Ultrasound in Pediatric Patients

Conditions
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Aspiration

Intervention / Treatment
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* Behavioral: lower pressure
* Behavioral: higher pressure


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: pediatric patients undergoing general anesthesia with LMA flexible Exclusion Criteria: Unstable vital sign, significant arrhythmia or hypotension, Shock anticipated difficult intubation or the patient who have facial deformity high risk of aspiration recent upper respiratory tract infection history

Ages Eligible for Study
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Minimum Age: 1 Year
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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: higher pressure<br>During the operation, cuff pressure of LMA flexible is maintained to 50cmH2O | Behavioral: higher pressure<br>* During the operation, cuff pressure of LMA flexible is maintained to 50cmH2O<br>|
| Experimental: lower pressure<br>During the operation, cuff pressure of LMA flexible is maintained to 30cmH2O | Behavioral: lower pressure<br>* During the operation, cuff pressure of LMA flexible is maintained to 30cmH2O<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of gastric insufflation(antrum) | Incidence of gastric insufflation which was recognized in gastric antrum with ultrasound | During the surgery(up to 3 hours) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The size of gastric antrum and body | The size of gastric antrum and body assessed immediately after insertion of LMA flexible and after finishing the surgery | During the surgery(up to 3 hours) | 
| Time for insertion of LMA flexible | Time for insertion of LMA flexible | During the anesthesia induction(up to 1 hour) | 
| Success rate of insertion of LMA flexible | Success rate of insertion of LMA flexible | During the anesthesia induction(up to 1 hour) | 
| The number of insertion attempt | The number of insertion attempt | During the anesthesia induction(up to 1 hour) | 
| The number and the type of additional manipulation for successful ventilation | The number and the type of additional manipulation for successful ventilation | During the surgery(up to 3 hours) | 
| Ease of insertion of LMA flexible | Ease of insertion of LMA flexible(very easy, easy, moerate, difficult, very difficult) | During the anesthesia induction(up to 1 hour) | 
| Incidence of gastric insufflation(body) | Incidence of gastric insufflation which was recognized in gastric body with ultrasound | During the surgery(up to 3 hours) | 
| Incidence of gastric insufflation recognized with the ausculation | Incidence of gastric insufflation recognized with the ausculation after finishing surgery | During the surgery(up to 3 hours) | 
| peak pressure observed before, during, after surgery | peak pressure observed before, during, after surgery | During the surgery(up to 3 hours) | 
| oropharyngeal leak pressure | oropharyngeal leak pressure will be assessed by setting the APL valve of the circle system at 30 cmH2O with fresh gas flow of 3 L/min after the surgery | During the surgery(up to 3 hours) | 
| the complication rate | the complication rate such as desaturation, blood staining of LMA flexible, hoarseness, dental/lip/tongue injury, aspiration | During the surgery and after surgery (up to 6 hours) |