Clinical usefulness of intermediate-dose dexmedetomidine (0.75 μg/kg) in flexible bronchoscopy – A prospective, randomized, double-blinded study

BACKGROUND: Dexmedetomidine, although an effective drug for conscious sedation during flexible bronchoscopy, has occasional side effects on the cardiovascular system which need to be addressed. MATERIALS AND METHODS: Patients between 18 and 65 years, requiring diagnostic flexible bronchoscopy, found eligible, after screening, were randomized to either receive 0.75 μg/kg intravenous dexmedetomidine over 10 min or intravenous midazolam 0.035 mg/kg over 1 min. Composite score was used as the primary outcome measure. Additional parameters recorded were: Hemodynamic variables, oxygen saturation, Ramsay sedation score, for pain intensity and distress Numerical Rating Scale, number of rescue medication doses, ease of doing bronchoscopy, Visual Analog Scale score for cough and response of the patient 24 h after bronchoscopy. RESULTS: In each group, 24 patients were enrolled. The composite score was in the ideal category in 24 patients in dexmedetomidine group and 21 in midazolam group, at nasopharynx (P = 0.234). The corresponding values at the level of trachea were 23 and 16 (P = 0.023). In dexmedetomidine group, patient response after 24 h of bronchoscopy showed quality of sedation to be excellent in 0 subjects, good in 13, fair in 9 and poor in 2 and discomfort to be nil in 7, mild 10, moderate in 7 and severe in 0. The corresponding values in midazolam group for quality of sedation were 0, 4, 14, 6, and for discomfort 0, 10, 14, 0. The Visual Analog Scale (VAS) for cough revealed a mean score of 0.800 and 1.812 (P = 0.011) during and 2.092 and 3.542 (P = 0.016) 24 h after bronchoscopy in the respective study groups. CONCLUSION: Low-dose dexmedetomidine (0.75 μg/kg single dose) appears to provide better patient comfort and equivalent safety profile when compared with midazolam.