Comparative evaluation of nebulized versus intravenous dexmedetomidine on intubating conditions during awake fiberoptic nasotracheal intubation

Background: There is a search for an ideal agent to facilitate awake fiberoptic intubation (AFOI). Dexmedetomidine is a selective alpha 2 agonist which can be administered through intravenous, intramuscular, buccal, intranasal & inhalational routes. It provides good intubation conditions without oxygen desaturation but may cause hypotension and bradycardia when administered intravenously. Hence, alternative routes of administering dexmedetomidine which may improve its safety profile are worth exploring. Methods: In this randomised, controlled, double-blind trial, 46 ASA I/II adult participants scheduled for elective ENT surgery were randomly allocated to Group ND (Nebulised Dexmedetomidine) (n = 23) to receive nebulisation with dexmedetomidine 1 mu g.kg(-1) and Group ID (Intravenous Dexmedetomidine) (n = 23) to receive intravenous dexmedetomidine 1 mu g.kg(-1) before AFOI. All the patients received injection midazolam 1 mg i.v. as premedication before anaesthesia was initiated. The primary outcome was the cough score. The secondary outcomes were the RSS, SAYGO boluses, post-intubation score, hemodynamic parameters, recall of the procedure, patient satisfaction score and any side effects. Results: The cough score was significantly lower in nebulized group (2.43 +/- 0.992 vs 3.52 +/- 1.082) with p = 0.001. RSS(3.30 +/- 0.926 vs 4.22 +/- 1.126; p = 0.004), number of SAYGO boluses required (2.74 +/- 0.864 vs 3.57 +/- 1.161; p = 0.009) & the post intubation score (1.48 +/- 0.593 vs 2.17 +/- 0.778; p = 0.001) were also significantly lower in nebulized group. Conclusions: Nebulisation with dexmedetomidine results in desirable degree of sedation and better tolerance of the procedure with adequate attenuation of the haemodynamic responses to intubation.