Target-Controlled Infusion of Propofol for Flexible Bronchoscopy Sedation

Study Overview
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Brief Summary
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Flexible bronchoscopy (FB) sedation requires keeping sedative level in a narrow window to prevent over or under sedation. Sedative drug titration according to subjective adjustment by individual physician may cause unsteady drug concentration. Target controlled infusion (TCI) has been provided a precise pharmacokinetic control of propofol, direct control the effect side, (eg. Brain) concentration (Ce), and been applied in surgical anesthesia and variable procedure sedation. We designed this pilot study to evaluate the optimal regimen of TCI in FB sedation.

Detailed Description
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Propofol is ideal for bronchoscopy sedation because of its fast onset and quick recovery effect. Our research and reports from different investigators demonstrate that patients received propofol sedation recover fast with excellent satisfaction for bronchoscopy. However, the amount of propofol for induction and maintenance is calculated simply by patient's body weight and physicians' experience. For those non-anesthesiologists, who perform sedative work outside the operating room, and inexperienced anesthesiologist without fully considering the individual pharmacokinetic and pharmacodynamic differences may generate unstable drug plasma concentration and increase cardio-respiration suppression. Therefore, a manner which can assess and measure objectively individual pharmacokinetic differences may improve the sedative quality and decrease the complication rate. A model called Target-controlled infusion(TCI), built from massive pharmacokinetic samples of propofol, could now give precise pharmacokinetic control. Several pharmacokinetic models built-in in TCI, includes the Schnider model which use concentration of effect site (Ce, the propofol concentration in the brain) as the sedative guide. The model integrates individual variants of age, height, weight and gender to calculate the infusion profile to achieve predetermined steady target effect site concentration (Cet). Because of the unique consideration of individual pharmacokinetic variants and Ce targeting, TCI provides predictable sedative level and is suitable for procedures requiring narrowing therapeutic level. Beside general anesthesia, TCI has been applied in breast biopsy, upper gastrointestinal endoscopic ultrasound and endoscopic retrograde cholangiopancreatography at outpatient clinic. According to these evidences, there is potential role of TCI in bronchoscopic sedation. Based on current evidence and our experience, we design this study to evaluate the optimal regimen for induction and procedure during bronchoscopy. We hope this study could provide the more safety and efficient bronchoscopic sedation for patients and physicians.

Official Title
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Target-Controlled Infusion of Propofol for Flexible Bronchoscopy Sedation: Determining the Optimal Titrating Regimen

Conditions
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Flexible Bronchoscopy

Intervention / Treatment
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* Procedure: TCI titration by different Cet.


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult patients (18 years old or more) required elective flexible bronchoscopy and sedation. Exclusion Criteria: American Society of Anesthesiologists classification of physical status 4 and 5, including hepatic or renal failure, severe obstructive sleep apnea and severe chronic obstructive pulmonary disease. Mallampati score 4 or 5. Significant Central nervous system disorders or other factors contributing to access consciousness difficultly. Men with body mass index(BMI) large than 42，Females with BMI large than 35. Allergic history to study drugs.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 95 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: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Titration by target effect site concentration (Cet) 0.5μg/ml<br>The investigator will titrate the Cet to keep stable vital signs and sedative level during the flexible bronchoscopy. The criteria for titration is descried in the intervention. | Procedure: TCI titration by different Cet.<br>* Induction: After topical xylocaine and alfentanil 5μg/kg iv 1 minute before, Cet 2.0μg/ml is started on the TCI pump ('Vial Injectomat TIVA Agilia syringe infusion pump, Fresenius Kabi, France). The sedative level will be accessed by sedation scale OAA/S every 30 seconds till OAA/S ≦3(Responds only to name called loudly). The current Ce will be set as the maintenance Cet. If desired OAA/S is not achieved after reaching 2.0μg/ml,Cet will be increased every 90 seconds by the regimens be assigned until OAA/S ≦3. The current Ce will be set as the maintenance Cet. Maintenance: The Cet will be increased according to the assigned regimens if: Patients become irritant and interfere procedures. Patients open eyes or talk to express uncomfortable. The Cet will be decreased if: Systolic blood pressure is less than 90mmHg; Mean arterial blood pressure is less than 65mmHg; Oxyhemoglobin saturation is less than 90 % with any duration.<br>|
| Active Comparator: Titration by Cet 0.2μg/ml<br>The investigator will titrate the Cet to keep stable vital signs and sedative level during the flexible bronchoscopy. The criteria for titration is descried in the intervention. | Procedure: TCI titration by different Cet.<br>* Induction: After topical xylocaine and alfentanil 5μg/kg iv 1 minute before, Cet 2.0μg/ml is started on the TCI pump ('Vial Injectomat TIVA Agilia syringe infusion pump, Fresenius Kabi, France). The sedative level will be accessed by sedation scale OAA/S every 30 seconds till OAA/S ≦3(Responds only to name called loudly). The current Ce will be set as the maintenance Cet. If desired OAA/S is not achieved after reaching 2.0μg/ml,Cet will be increased every 90 seconds by the regimens be assigned until OAA/S ≦3. The current Ce will be set as the maintenance Cet. Maintenance: The Cet will be increased according to the assigned regimens if: Patients become irritant and interfere procedures. Patients open eyes or talk to express uncomfortable. The Cet will be decreased if: Systolic blood pressure is less than 90mmHg; Mean arterial blood pressure is less than 65mmHg; Oxyhemoglobin saturation is less than 90 % with any duration.<br>|
| Active Comparator: Titration by Cet 0.1μg/ml<br>The investigator will titrate the Cet to keep stable vital signs and sedative level during the flexible bronchoscopy. The criteria for titration is descried in the intervention. | Procedure: TCI titration by different Cet.<br>* Induction: After topical xylocaine and alfentanil 5μg/kg iv 1 minute before, Cet 2.0μg/ml is started on the TCI pump ('Vial Injectomat TIVA Agilia syringe infusion pump, Fresenius Kabi, France). The sedative level will be accessed by sedation scale OAA/S every 30 seconds till OAA/S ≦3(Responds only to name called loudly). The current Ce will be set as the maintenance Cet. If desired OAA/S is not achieved after reaching 2.0μg/ml,Cet will be increased every 90 seconds by the regimens be assigned until OAA/S ≦3. The current Ce will be set as the maintenance Cet. Maintenance: The Cet will be increased according to the assigned regimens if: Patients become irritant and interfere procedures. Patients open eyes or talk to express uncomfortable. The Cet will be decreased if: Systolic blood pressure is less than 90mmHg; Mean arterial blood pressure is less than 65mmHg; Oxyhemoglobin saturation is less than 90 % with any duration.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The Number of Patients With Hypoxemia During Flexible Bronchoscopy | Hypoxemia is defined as: Oxyhemoglobin saturation (SPO2) is less than 90 % with any duration | During sedative induction and bronchoscopy | 
| The Number of Changes in Target Effect Site Concentration During Flexible Bronchoscopy | The investigator will titrate the target effect site concentration (Cet) during bronchoscopy according to protocol to keep stable vital signs and sedative levels. The numbers of adjustment will be recorded to show which regimen required less adjustment to keep stable sedative levels and vital signs. | During sedative induction and bronchoscopy | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The Recovery Time to Orientation | The recovery time to orientation was defined as the time between finishing bronchoscopy to the time when the patients could spontaneously open their eyes, recall their date of birth, and correctly perform finger-nose test. | after bronchosocpy | 
| The Total Doses of Propofol During Induction and Overall Procedures | The dosses of propofol used during induction and overall flexible bronchoscopy will be recored from the screen of the TCI pump. | after bronchoscopy | 
| The Cooperation of Patients From the View of Bronchoscopists | After the bronchoscopy, the bronchoscopist will be asked by 10-point Verbal Analogus Scale (0: the best cooperation, 10: the worst cooperation) to express how they fell about the cooperation of patients undergoing the bronchoscopy. | After bronchoscopy | 
| The Global Tolerance for Flexible Bronchoscopy | After the recovery, patients will be asked about the tolerance of bronchoscopy performed to them by 10-point Verbal Analogus Scale (0: best tolerance, 10: worst tolerance) | After recovery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Target-controlled infusion,, bronchoscopy,, sedation,, propofol