Dexmedetomidine for Sedation of Endobronchial Ultrasound-guided Transbronchial Needle Aspiration
Condition: Bronchoscopy
Study type: Interventional
Phase: Phase 4

Summary: 
      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: 
      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.
    

Intervention name(s): Dexmedetomidine arm; Propofol arm
Intervention type(s): Drug; Drug
Intervention description(s): 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; 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.
Intervention MeSH terms: Dexmedetomidine; Propofol
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Other
Keywords: Sedation; dexmedetomidine; brain perfusion; bronchoscopy