The EC50 of Remifentanil Blunting Hemodynamic Response to Double Lumen Tube Intubation

Study Overview
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Brief Summary
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The purpose of this study is to evaluate the effect site concentration of remifentanil blunting hemodynamic changes to tracheal intubation of single or double lumen tubes.

Official Title
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The Effect Site Concentration of Remifentanil Blunting Hemodynamic Responses to Tracheal Intubation: Single Versus Double Lumen Tube

Conditions
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Hemodynamic Responses During Tracheal Intubation

Intervention / Treatment
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* Drug: Remifentanil
* Drug: Remifentanil


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients undergoing thoracic surgery that require one lung ventilation Exclusion Criteria: patient who does not agree with this study BMI < 16.0 or BMI > 30 cardiovascular disease, pulmonary disease, renal disease alcoholic abuser or drug abuser patient who takes any drug to influence cardiovascular system or sympathetic nervous system any use of local anesthetics or drugs to influence cardiovascular system during tracheal intubation

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
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Single lumen tube<br>Single lumen tube intubation during remifentanil infusion | Drug: Remifentanil<br>* According to previous patient's response, the investigators will allocate the effect site concentration of remifentanil of next patient during single lumen tube intubation. For this allocation of dose of remifentanil the investigators use up-and-down method. For the first patient, the dose of remifentanil would be fixed at 6.0 ng/ml which we predict as EC50. Step size of dose is 0.5ng/ml.<br>|
| Active Comparator: Double lumen tube<br>Double lumen tube intubation during remifentanil infusion | Drug: Remifentanil<br>* According to previous patient's response, the investigators will allocate the effect site concentration of remifentanil of next patient during double lumen tube intubation. For this allocation of dose of remifentanil the investigators use up-and-down method. For the first patient, the dose of remifentanil would be fixed at 6.0 ng/ml which we predict as EC50. And, step size of dose is 0.5ng/ml.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes from baseline in heart rate and mean arterial pressure after intubation | Heart rate and mean arterial pressure will be recorded at 2 minutes before intubation, 1 minute before intubation, during intubation, 1 minute after intubation. The mean value of heart rate and mean arterial pressure before intubation will be regarded as the baseline values. If maximum heart rate or mean arterial pressure after intubation increased by >15% from baseline value, the response will be regarded as fail and increased concentration of remifentanil will be applied to next patient by up and down sequential method. | intubation period |