['Propofol is an accepted method of sedation for an ERCP and generally achieves deep sedation rather than conscious sedation, and dexmedetomidine has sedative properties of equivalent efficacy.', 'To examine the hypothesis that dexmedetomidine is as effective as propofol combined with fentanyl for providing conscious sedation during an ERCP.', 'Randomized, blind, double-dummy clinical trial.', 'Twenty-six adults, American Society of Anesthesiologists status I to III, underwent an ERCP.', 'Patients were randomized to receive either propofol (n = 14) (target plasma concentration range 2-4 microg/mL) combined with fentanyl 1 microg/kg, or dexmedetomidine (n = 12) 1 microg/kg for 10 minutes, followed by 0.2 to 0.5 microg/kg/min. Additional sedatives were used if adequate sedation was not achieved at the maximum dose allowed.', 'The sedation level was assessed by the Richmond alertness-sedation scale and the demand for additional sedatives. Furthermore, heart rate, blood pressure, oxygen saturation, and respiratory rate were continuously assessed.', 'The relative risk (RR) was 2.71 (95% CI, 1.31-5.61) and the number of patients that needed to be treated (NNT) was 1.85 (95% CI, 1.19-4.21) to observe one additional patient with drowsiness 15 minutes after sedation in the dexmedetomidine group. Also, the RR was 9.42 (95% CI, 1.41-62.80), and the NNT was 1.42 (95% CI, 1.0-2.29) to require additional analgesic. However, there was also a greater reduction in blood pressure, a lower heart rate, and greater sedation after the procedure.'] Is clinical efficacy of dexmedetomidine alone less than propofol for conscious sedation during ERCP?