A Prospective Randomized Controlled Study Comparing Intravenous and Nebulised Dexmedetomidine for Awake Fibreoptic...

Awake fiberoptic intubation (AFOI) is the gold standard for anticipated difficult airways but is limited by patient discomfort and hemodynamic stress. Dexmedetomidine may improve tolerance while preserving spontaneous ventilation. We compared intravenous and nebulized dexmedetomidine for AFOI.

In this prospective, randomized, double-blind trial, 46 American Society of Anesthesiologists (ASA) physical status I-II adults undergoing elective surgery requiring nasotracheal intubation were assigned to two groups. Patients in the nebulization group (Group N) received dexmedetomidine 1 μg/kg, combined with 4 mL of 4% lignocaine, via nebulization for four minutes, along with 20 mL of intravenous normal saline infused over 10 minutes. Patients in the intravenous group (Group I) were administered dexmedetomidine 1 μg/kg diluted in 20 mL normal saline intravenously over 10 minutes, along with 4 mL of 4% lignocaine via nebulization for four minutes. Sedation (Modified Observer's Assessment of Alertness/Sedation scale (OAA/S)), intubation conditions (cough severity, facial grimace), intubation time, hemodynamics, adjunct requirements (propofol dose; spray-as-you-go (SAYGO) lignocaine boluses), discomfort, recall, complications, and willingness to repeat anesthesia were assessed. P <0.05 was considered significant.

Baseline demographics were comparable. Adequate sedation (OAA/S ≤ 3) without propofol occurred in 100% with IV vs 0% with nebulization. Propofol requirement was lower in the intravenous group (0.74 ± 1.14 vs 4.22 ± 1.31 mg/kg; p<0.001). Intubation was faster in the intravenous group (5.22 ± 2.26 vs 8.00 ± 2.02 min; p=0.007). Cough was reduced in the intravenous group (no cough 69.6% vs 0%; severe cough >5 in sequence 0% vs 21.7%). Fewer SAYGO boluses were needed with intravenous (4.00 ± 1.51 vs 5.09 ± 1.88; p=0.04). Hemodynamics were stable and similar overall; one hypotension event occurred in the nebulization group. Postoperative complications were negligible. Discomfort was lower, and willingness to undergo the same technique again was higher with IV dexmedetomidine.

When combined with standardized nebulized lignocaine airway topicalization, intravenous dexmedetomidine 1 μg/kg provided superior sedation quality, better intubating conditions, reduced adjunct use, and shorter intubation time compared with nebulized dexmedetomidine, with comparable safety. Intravenous administration may therefore be preferred for sedation during AFOI.