Dexmedetomidine for Sedation of Endobronchial Ultrasound-guided Transbronchial Needle Aspiration

Study Overview
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Brief Summary
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Preventing hypoxemia is one of the major goal of studies for bronchoscopic sedation. Dexmedetomidine is a sedative agents via α2 adrenergic agonist, with little respiratory suppression. In the preset study, we evaluate the safety and feasibility of the Dexmedetomidine in the specific bronchoscopic procedure, endobronchial ultrasound (EBUS)-guided transbronchial needle aspiration.

Detailed Description
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Patients undergoing flexible bronchoscopy (FB) experience procedure-related symptoms. Current guidelines of FB recommend sedation to all patients undergoing FB, except when there are contraindications. Propofol plus an opioid is the common combination used to improve patient tolerance and satisfaction during FB. However, controversy about combining propofol and opioids persists because of the risk of over-sedation and cardiopulmonary depression, especially for the time-consuming endobronchial ultrasound (EBUS)-guided transbronchial needle aspiration (TBNA). Similar with other published data, around 40% of hypoxemia event was observed during FB sedation in the investigators' hospital. Dexmedetomidine, is a sedative agents via α2 adrenergic agonist, with little respiratory suppression. It has been applied in patients with mechanical ventilation, undergoing gastroendoscopy and extracorporal shockwave lithotripsy. Little evidences are available for Dexmedetomidine in sedation for EBUS-TBNA. In this study, the investigators will evaluate the safety and feasibility of Dexmedetomidine for sedation of EBUS-TBNA comparing to Propofol for sedation of EBUS-TBNA. Generally, the FB sedation can divided into three parts: the induction (from starting sedative administration to insertion of bronchoscope); the maintenance ( from insertion of bronchoscope to its removal) and the recovery (from bronchoscope removal to patients gain consciousness). The primary endpoint is the proportion of patients with hypoxemia during maintenance of sedation. the investigators will also observe the other sedative outcomes, e.g. blood pressure, sedative drug dosing and patient tolerance and cooperation. The present study will also observe the association between brain perfusion and sedative outcomes via non-invasive monitor. Based on the unique pharmacokinetic property of Dexmedetomidine and the real-time brain perfusion monitor, Dexmedetomidine-based sedation may provide better safety profile for EBUS-TBNA than propofol and discover novel connection between sedative outcomes and brain perfusion.

Official Title
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Dexmedetomidine and Brain Perfusion Monitor for Sedation of Endobronchial Ultrasound-guided Transbronchial Needle Aspiration

Conditions
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Bronchoscopy

Intervention / Treatment
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* Drug: Dexmedetomidine arm
* Drug: Propofol arm


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients undergoing elective bronchoscopy and sedation Exclusion Criteria: Age less than 20 years American Society of Anaesthesiologists (ASA) physical status classification IV or V Mallampati score of 4 Severe sleep apnoea syndrome (apnoea-hypopnea index more than 40) Body mass index more than 42 in males or 35 in females Neurologic disorders or other conditions contributing to difficulty in assessing response Forced expiratory vital capacity (FVC) less than 15 ml/kg body weight, forced expiratory volume in one second (FEV1) less than 1000 ml, or FEV1/FVC less than 35% History of second or third degree atrioventricular block, heat rate less than 50 beat per minute or systolic blood pressure less than 90 mmHg Pregnancy Patients with a known history of allergy to the study drugs, or to eggs, soybeans or sulfite products

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 80 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: Other
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Dexmedetomidine arm<br>Dexmedetomidine will be administrated for sedation of EBUS-TBNA | Drug: Dexmedetomidine arm<br>* Induction: Dexmedetomidine 1ug/kg infusion for 10 minutes. 5 mg/kg alfentanil (1:10 dilution) slow injection 2 min before complete Dexmedetomidine induction Maintenance: Dexmedetomidine 0.5 1.4ug/kg/hour infusion±0.2ug/kg/hour to maintain stable vital signs and The Observer Assessment of Alertness and Sedation scale (OAA/S) 3 2. the infusion rate was increased by 0.2ug/kg/hour if the patient persistently had eye opening, talked, or became irritable and interfered with the procedure. The infusion rate was reduced by 0.2ug/kg/hour, if the following adverse events occurred: hypoxemia (SpO2 < 90%) or hypotension (mean arterial pressure (MAP) < 65 mmHg, or systolic blood pressure (SBP) < 90 mmHg) in any duration<br>|
| Active Comparator: Propofol arm<br>Propofol will be administrated for sedation of EBUS-TBNA | Drug: Propofol arm<br>* 5 mg/kg alfentanil (1:10 dilution) slow injection 2 min before induction Induction: The initial effect-site concentration (Ce) of propofol was targeted to 2.0 μg/ml for induction (Schneider model of target-controlled infusion (TCI), Injectomat total intravenous anaesthesia (TIVA) Agilia, Fresenius Kabi, France). If OAA/S did not reach 3 while Ce achieved 2.0 μg/ml, Ce was increased by 0.2 μg/ml every 90 seconds until OAA/S 3 2. Maintenance: the Ce was increased by 2.0 μg/mL every 90 seconds if the patient persistently had eye opening, talked, or became irritable and interfered with the procedure. The Ce was reduced by 0.2 μg/ml every 90 seconds, if the following adverse events occurred: hypoxemia (SpO2 < 90%) or hypotension (mean arterial pressure (MAP) < 65 mmHg, or systolic blood pressure (SBP) < 90 mmHg) in any duration.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Hypoxemia During Maintenance | The percentage of patients with hypoxemia (oxyhemoglobin saturation (SpO2)<90%) during maintenance of Bronchoscopic sedation | After starting bronchoscopy, up to 120 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Hypoxemia During Induction | The percentage of patients with hypoxemia (oxyhemoglobin saturation (SpO2)<90%) during induction of bronchoscopic sedation | After starting induction, up to 30 minutes. | 
| The Global Tolerance for Bronchoscopy | The Global Tolerance of patients for bronchoscopy will be evaluated by 100-mm visual analogue scale (VAS, 0: no bother, 100: worst intolerable) after recovery | After recovery from sedation, up to 120 minutes | 
| The Cooperation of Patients From the View of Bronchoscopists | The Cooperation of Patients will be evaluated by 100-mm visual analogue scale (VAS, 0: well cooperation, 100: worst cooperation) after recovery. | After recovery from sedation, up to 120 minutes | 
| Hypotension During Bronchoscopic Sedation | The percentage of patients with hypotension (mean arterial blood pressure (MAP) less than 65 mmHg with any duration. | After starting sedation, up to 120 minutes. | 
| Bradycardia During Bronchoscopic Sedation | The percentage of patients with bradycardia (heat beat per minute less than 60) | After starting sedation, up to 120 minutes. | 
| Procedure Time and Recovery Time | The procedure time of bronchoscopy and recovery time from sedation to awake. | After starting bronchoscopy, up to 120 minutes. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Sedation, dexmedetomidine, brain perfusion, bronchoscopy