Comparison between Dexmedetomidine and Midazolam-Fentanyl Combination in Flexible Bronchoscopy: A Prospective, Randomized, Double-blinded Study

Background: Dexmedetomidine has acceptable clinical utility for inducing sedation during flexible bronchoscopy. Reducing its dose may not only ameliorate its cardiovascular side effects, but also maintain its clinical usefulness. Methods: Patients between 18 and 65 years were randomized to either dexmedetomidine (0.75 µg/kg) or the midazolam-fentanyl group (0.035 mg/kg midazolam and 25 mcg fentanyl). The primary outcome measure was the composite score. Other parameters noted were: oxygen saturation, hemodynamic variables, Modified Ramsay Sedation Score, Numerical Rating Scale (NRS) for pain intensity and distress, Visual Analog Scale score for cough, rescue medication doses, ease of doing bronchoscopy, and patient response 24 hours after bronchoscopy. Results: In each arm, 31 patients were enrolled. The composite score at the nasopharynx was in the ideal category in 26 patients in dexmedetomidine and 21 in the midazolam-fentanyl group (P=0.007). At the tracheal level, the corresponding values were 24 and 16 (P=0.056). There was no significant difference between the 2 groups regarding the secondary outcome measures except hemodynamic parameters. The mean heart rate in the dexmedetomidine and midazolam-fentanyl groups, respectively, was as follows: at 10 minutes after start of FB (90.10±14.575, 104.35±18.48; P=0.001), at the end of FB (98.39±18.70, 105.94±17.45; P=0.016), and at 10 minutes after end of FB (89.84±12.02, 93.90±13.74; P=0.022). No patient developed bradycardia. Two patients (P=0.491) in the dexmedetomidine group developed hypotension. Conclusion: Low-dose dexmedetomidine (0.75 μg/kg single dose) appears to lead to a better composite score compared with the midazolam-fentanyl combination.