Abstract. The aim of the present study was to evaluate the effect of a combination of dexmedetomidine and fentanyl on peripheral oxygen saturation (SpO 2 ) and hemodynamic stability in patients undergoing flexible bronchoscopy. One hundred patients undergoing elective flexible bronchoscopy were randomized into either a propofol-fentanyl group (PF group; n=50) or a dexmedetomidine-fentanyl group (DF group; n=50). SpO 2 values, heart rate (HR), systolic and diastolic blood pressure (SBP and DBP), patients' cough scores and discomfort scores as determined by patients and bronchoscopists, levels of sedation, number of times that additional lidocaine was required, elapsed time until recovery, and adverse events were recorded. The mean SpO 2 values in the DF group were significantly higher than those in the PF group (P<0.01), and HR, SBP and DBP were significantly lower in the DF group than in the PF group (P<0.05). There were no statistically significant differences between the two groups in terms of cough scores or discomfort scores, sedation levels, or number of times that additional lidocaine was required (P>0.05). Elapsed time until recovery in the DF group was significantly longer than in the PF group (P=0.002). The incidence of hypoxemia was significantly lower in the DF group than in the PF group (P= 0.027), but the incidence of bradycardia was significantly higher in the DF group than in the PF group (P= 0.037). Dexmedetomidine-fentanyl was superior to propofol-fentanyl in providing satisfactory SpO 2 . Furthermore, dexmedetomidine-fentanyl attenuated hemodynamic responses during bronchoscopy and maintained hemodynamic stability in the early stage of the procedure.
IntroductionFlexible bronchoscopy is commonly used for the diagnosis and management of a variety of pulmonary diseases. However, it is an invasive procedure that can induce coughing, pain, dyspnea and other adverse effects (1,2). The use of sedatives not only can increase patients' safety and comfort (3) but also can make it easier for the bronchoscopist to perform the procedure and thus avoid extending its duration (4). In addition to alleviating the physiological response to airway irritation during the procedure (5), the proper sedatives should have a rapid onset and a short duration of action, in addition to allowing rapid recovery.Propofol, a non-opioid and nonbarbiturate sedative hypnotic agent, is frequently used in the induction and maintenance of anesthesia. The properties of rapid onset and offset of action and of smooth recovery (6) make propofol an appealing agent alone or in combination with an opioid for procedural sedation (7-10). However, dose-dependent respiratory depression and hypoxemia are possible, owing to interactions and synergism between sedatives and opioids (11-13).Dexmedetomidine, a highly selective α 2 -adrenoceptor agonist, has an affinity for α 2 -adrenoceptors that is 8-fold greater than that of clonidine (14). In addition to providing sedative and analgesic effects (15), dexmedetomidine can be applied generally duri...