Efficacy and Safety of Dexmedetomidine Nasal Spray as a Premedication in Patients Undergoing Fiberoptic Bronchoscopy Under Sedation: A Randomized Controlled Trial

Background: Fiberoptic bronchoscopy (FB) under sedation can provoke patient discomfort, cough, and hemodynamic fluctuations. This study evaluated the efficacy and safety of dexmedetomidine nasal spray as a premedication compared to intranasal normal saline and lidocaine. Methods: A total of 90 patients scheduled for FB under sedation were randomly assigned to three groups. Group D (dexmedetomidine), Group C (control, normal saline), and Group L (lidocaine) received pre-induction nasal sprays via the same metered-dose aerosolization device. At 10 min post-spray, all patients received standard monitored anesthesia care (MAC) with preserved spontaneous ventilation (respiratory rate, RR ≥ 10 breaths/min; peripheral oxygen saturation, SpO 2 ≥ 95%). Outcomes included hemodynamic parameters (heart rate, HR; mean arterial pressure, MAP) measured at specific time points (T 1 -T 8 ), Modified Observer’s Assessment of Alertness/Sedation (MOAA/S) scores, cough severity and adverse events. Results: Group D demonstrated better overall performance. Hemodynamically, HR in Group D was lower than Group C at T 3 and T 5 , and lower than Group L at T 5 . MAP in Group D was lower than both control groups from T 3 -T 6 . Recovery time in Group D was shorter than in both Group C and Group L. Group D also exhibited superior MOAA/S scores (lower at T 1 , but higher at T 6 -T 8 ), higher bronchoscopist satisfaction, and a lower incidence of both moderate-to-severe cough and postoperative nausea and vomiting (PONV) compared to the other groups. Respiratory rates were comparable, with Group D showing a higher RR than Group C at T 6 . Conclusion: Premedication with dexmedetomidine nasal spray in patients undergoing FB under sedation was associated with more effective suppression of procedure-induced cough, better hemodynamic stability, a lower incidence of PONV, and a faster recovery profile compared to both intranasal saline and lidocaine, without increasing respiratory depression. Consequently, dexmedetomidine nasal spray can effectively and safely enhance patient comfort and safety, and optimize the procedural conditions for the bronchoscopists. Keywords: dexmedetomidine nasal spray, normal saline, lidocaine, fiberoptic bronchoscopy, sedation