Comparison of Effect-site Concentration of Remifentanil for Preventing Cough Against Endotracheal Tube During Anesthetic Emergence According to Anesthetics (Sevoflurane, Desflurane, and Propofol)

Study Overview
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Brief Summary
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It has been reported that target-controlled infusion of remifentanil can reduce cough against endotracheal tube during emergence from general anesthesia. We hypothesized that effective concentration of remifentanil for preventing cough during anesthetic emergence varies depending on the type of main anesthetic agents which is administered with remifentanil during general anesthesia. The purpose of this study is to evaluate the effective concentrations of remifentanil to prevent coughing during emergence from general anesthesia according to main anesthetic agent (sevoflurane, desflurane, and propofol).

Conditions
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Female Patients Undergoing Thyroidectomy

Intervention / Treatment
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* Drug: up-and-down method to find out effective concentration of remifentanil for preventing cough


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: aged 20-60 ASA classification I II female patients patients who undergoing thyroidectomy Exclusion Criteria: Patients with acute or chronic respiratory disease patient who has smoking history patient who has hypertension patient who has esophageal reflux patient who having an expectorant or cough remedy

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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Female

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: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Sevo group<br>undergoing sevoflurane-remifentanil anesthesia | Drug: up-and-down method to find out effective concentration of remifentanil for preventing cough<br>* During the emergence from anesthesia, if the patient did not cough, the extubation was defined as smooth emergence and the predetermined effect site concentration of remifentanil for the subsequent patient was decreased by 0.5 ng/mL. Likewise, if the patient coughed anytime around extubation, it was considered a failed smooth emergence and the predetermined effect site concentration for the next patient was increased by 0.5 ng/mL. This up-and-down method was conducted independently for each of the three groups. EC50 of the remifentanil of each group was obtained using the Dixon's method.<br>|
| Active Comparator: Des group<br>undergoing desflurane-remifentanil anesthesia | Drug: up-and-down method to find out effective concentration of remifentanil for preventing cough<br>* During the emergence from anesthesia, if the patient did not cough, the extubation was defined as smooth emergence and the predetermined effect site concentration of remifentanil for the subsequent patient was decreased by 0.5 ng/mL. Likewise, if the patient coughed anytime around extubation, it was considered a failed smooth emergence and the predetermined effect site concentration for the next patient was increased by 0.5 ng/mL. This up-and-down method was conducted independently for each of the three groups. EC50 of the remifentanil of each group was obtained using the Dixon's method.<br>|
| Active Comparator: Pro group<br>undergoing propofol-remifentanil anesthesia | Drug: up-and-down method to find out effective concentration of remifentanil for preventing cough<br>* During the emergence from anesthesia, if the patient did not cough, the extubation was defined as smooth emergence and the predetermined effect site concentration of remifentanil for the subsequent patient was decreased by 0.5 ng/mL. Likewise, if the patient coughed anytime around extubation, it was considered a failed smooth emergence and the predetermined effect site concentration for the next patient was increased by 0.5 ng/mL. This up-and-down method was conducted independently for each of the three groups. EC50 of the remifentanil of each group was obtained using the Dixon's method.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| occurrence of cough | We will assess the occurrence of cough during emergence from general anesthesia in female patients undergoing target controlled infusion of remifentanil at predetemined concentration. | From the completion of surgery to 5minute after extubation |