Comparison of Tapered- vs. Cylindrical-shaped Tube Cuffs Pressure Alteration With Nitrous Oxide

Study Overview
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Brief Summary
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When using nitrous oxide for general anesthesia, nitrous oxide diffusion induces intracuff hyperinflation of the endotracheal tube. Furthermore the difference among various types of cuffed endotracheal tubes in cuff pressure behavior during nitrous oxide exposure. TaperGuard(TM) tube has been newly introduced and has tapered-shape cuff. In vitro study, the intracuff pressure of TaperGuard(TM) tube was lower than that of conventional tube with cylindrical-shaped cuff of the conventional tube(Hi-Lo(TM) tube). Therefore, this clinical study is needed to evaluate the intracuff pressure during general anesthesia with nitrous oxide exposure.

Detailed Description
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During 60 minutes after routine anesthetic induction and intubation of the endotracheal tubes, intracuff pressures will be measured every 10 minutes with a manometer (VBM, Sulz, Germany). 60% nitrous oxide will be added at time 0. For 60 minutes from the beginning of general anesthesia, intracuff pressures will be measured every 10 minutes. After 60 minutes, Intracuff pressures will be maintained around 20 cm H2O during the remaining period of the surgery. The questionnaire for a sore throat, hoarseness, and dysphagia will be questioned at about 1, 6, and 24 hours after the surgery and the general anesthesia.

Official Title
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Comparison of Tapered- vs. Cylindrical-shaped Tube Cuffs Pressure Alteration With Nitrous Oxide Diffusion Under General Anesthesia

Conditions
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Adverse Effect of Other General Anesthetics, Anesthesia Intubation Complication, Inhalation of Nitrous Oxide, Trachea

Intervention / Treatment
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* Device: Cylindrical-shape cuff ETT (Group C)
* Device: Tapered-shape cuff ETT (Group T)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients who will undergo general anesthesia in a supine position with a neutral position of the head (hand and forearm sugery) 18 70 years old American society of anesthesiologists physical status 1-2 Body mass index < 30 kg/m2 Exclusion Criteria: Contraindication for nitrous oxide Difficult intubation Cormack-Lehane grade > 3 Airway-related or pulmonary diseases Short or long operation time (< 1 hour or > 3 hours)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 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

Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Cylindrical-shape cuff ETT (Group C)<br>Control group: Mallinckrodt HiLo(TM) endotracheal tube. Intracuff pressures of the tubes every 10 minutes, Adult patients under general anesthesia with Mallinckrodt Hi-Lo(TM) tube. | Device: Cylindrical-shape cuff ETT (Group C)<br>* Randomized allocation of the endotracheal cuffs for general anesthesia, mechanical ventilation will be maintained with Mallinckrodt Hi-Lo(TM) endotracheal tube.<br>* Other names: Mallinckrodt Hi-Lo(TM) endotracheal tube;|
| Experimental: Tapered-shape cuff ETT (Group T)<br>Experimental group: Mallinckrodt TaperGuard(TM) endotracheal tube. Intracuff pressures of the tubes every 10 minutes, Adult patients under general anesthesia with Mallinckrodt TaperGuard(TM) tube. | Device: Tapered-shape cuff ETT (Group T)<br>* Randomized allocation of the endotracheal cuffs for general anesthesia, mechanical ventilation will be maintained with Mallinckrodt TaperGuard(TM) endotracheal tube.<br>* Other names: Mallinckrodt TaperGuard(TM) endotracheal tube;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Intracuff pressure of the endotracheal tube after 60 min (1 hour) with exposure to nitrous oxide |  | One hour after the exposure to nitrous oxide under general anesthesia | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Intracuff pressure of the endotracheal tubes | Intracuff pressures will be measured with a manometer (VBM, Sulz, Germany) | 0, 10, 20, 30, 40, 50 minutes after exposure to nitrous oxide | 
| Postoperative sore throat: incidence |  | About 1, 6, 24 hours after termination of anesthesia | 
| Postoperative hoarseness: incidence |  | About 1, 6, 24 hours after termination of anesthesia | 
| Postoperative dysphagia: incidence |  | About 1, 6, 24 hours after termination of anesthesia | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Cuff pressure, Cylindrical cuff, Endotracheal tube, Nitrous oxide, Tapered cuff