Estimating EC95 of Remifentanil for Cough Prevention During Emergence From Total Intravenous Anesthesia With Propofol and Remifentanil in Patients Undergoing Transsphenoidal Hypophysectomy

Study Overview
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Brief Summary
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In patients undergoing hypophysectomy through transsphenoidal approach, preventing cough during anesthetic emergence is important to avoid hemorrhage and cerebrospinal fluid leakage. Previous reports demonstrated that administration of remifentanil during anesthetic emergence could reduce the incidence and severity of cough during anesthetic emergence. Therefore, the objective of this study is to determine EC95 of remifentanil for preventing cough during anesthetic emergence in patients undergoing hypophysectomy with transsphenoidal approach.

Conditions
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Hypophysectomy

Intervention / Treatment
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* Drug: Administration of remifentanil with TCI system


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: scheduled to undergo hypophysectomy with transsphenoidal approach American Society of Anesthesiologists physical status I or II more than 20 years old Exclusion Criteria: acute or chronic respiratory disease uncontrolled hypertension taking sedatives or anti-tussive gastro-esophageal reflux pregnant or breast feeding patients who cannot understand statements for subjects or this study itself

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 65 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
Intervention Model: Single Group Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: group 1<br>administration of remifentanil with target-controlled infusion (TCI) system at a given concentration during anesthetic emergence | Drug: Administration of remifentanil with TCI system<br>* A given effect site concentration of remifentanil would be administered to subjects using TCI system. According to biased coin design, the given concentration of remifentanil is determined according to success or failure of just previously enrolled patient. If the former patient did not cough during anesthetic emergence at a given concentration (success), the next patient will be randomly allocated into the same concentration of remifentanil with 18/19 of probability or the lower concentration of remifentanil by 0.4 ng/ml with 1/19 of probability. If the former patient coughed during anesthetic emergence (failure), the next will be automatically allocated into the higher concentration of remifentanil by 0.4 ng/ml.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The occurrence of cough during anesthetic emergence | At a given effect-site concentration of remifentanil, if cough does not occur during anesthetic emergence, it would be considered as a success. On the other hand, if cough occurs during anesthetic emergence, it would be considered as a failure. | 5 min after extubation | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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EC95, effective concentration in 95% of subjects