Objective To investigate the efficacy of dexmedetomidine combined with target-controlled infusion (TCI) of propofol and remifentanil for fiberoptic bronchoscopy in the elderly patients.Methods Forty ASA Ⅱ or Ⅲ patients,aged 65-75 yr,with body mass index of 20-30 kg/m2,scheduled for elective fiberoptic bronchoscopy,were randomly divided into 2 groups (n =20 each):control group (group C) and dexmedetomidine group (group D).In group D,a loading dose of dexmedetomidine 0.5/μg/kg was injected at 10 min before induction of anesthesia,followed by infusion at 0.5 μg· kg-1 · h-1 until the end of fiberoptic bronchoscopy.While the equal volume of normal saline was given instead in group C.Anesthesia was induced with TCI of propofol and remifentanil.The target effect-site concentration (Ce) of propofol was 3 μg/ml.When the plasma concentration and Ce were balanced,TCI of remifentanil (target Ce 4 ng/ml) was started.The fiberoptic bronchoscope was placed after consciousness was lost and then the Ces of propofol and remifentanil were adjusted to 1-3 μg/ml and 2-4 ng/ml,respectively.MAP,HR and OAA/S score were recorded before induction (T0),immediately after induction (T1),when the tip of fiberoptic bronchoscope reached the glottis (T2) and carina (T3),at the end of bronchoscopy (T4)and 10 min after the end of bronchoscopy (T5).The consumption of propofol and remifentanil,duration of bron-choscopy,emergence time,adverse cardiovascular events and side effects such as hyoxemia,nausea and vomiting,regurgitation and aspiration were recorded.Results Compared with group C,OAA/S score at T5 and the consumption of propofol and remifentanil was reduced,and emergence time was shortened,and the incidence of hypotension and hyoxemia was decreased in group D (P ＜ 0.05).No patients developed side effects such as hyoxemia,nausea and vomiting,regurgitation and aspiration in both groups.Conclusion Dexmedetomidine (infusion at 0.5 μg·kg-1 ·h-1 after a loading dose of 0.5 μg/kg) combined with TCI of propofol and remifentanil can be safely and effectively used for fiberoptic bronchoscopy in the elderly patients.