Evaluation of different doses of dexmedetomidine alone versus the combination of dexmedetomidine and fentanyl in sedation during awake fiberoptic intubation in oral cancer surgery patients: A prospective, randomized, double-blind clinical trial.

BACKGROUND: Awake fiberoptic intubation (AFOI) is one of the principal techniques in the management of difficult airway in oral cancer surgery. We hypothesized that the addition of a small dose of fentanyl could improve the sedative criteria of dexmedetomidine during AFOI technique, without the need to increase the dose of dexmedetomidine which may be associated with airway compromise.

PATIENTS AND METHODS: One hundred and fifty American Society of Anesthesiologists physical status 1 and 2 patients planned for AFOI for oral cancer surgery patients were allocated into three groups (fifty patients each). Group D1: Received an infusion of 1 μcg/kg dexmedetomidine diluted in 50 ml saline over 20 min. Group D2: Received an infusion of 2 μcg/kg dexmedetomidine diluted in 50 ml saline over 20 min. Group DF: Received an infusion of 1 μcg/kg dexmedetomidine added to 1 μcg/kg fentanyl diluted in 50 ml saline over 20 min. AFOI was done by topical anesthesia and with the same technique in all patients. All patients were assessed for: airway obstruction, intubation scores (vocal cord movement, coughing, and limb movement), fiberoptic intubation scores, and hemodynamic variables. Any episode of bradycardia or hypoxia was recorded and managed.

RESULTS: Group D2 showed more incidence of airway obstruction than the other two groups. Limb movement scores were more in Group D1 compared to the other two groups. All groups were comparable as regard fiberoptic intubation scores, coughing, and vocal cord opening scores.

CONCLUSION: Adding a low dose of fentanyl (1 μcg/kg) to a low dose of dexmedetomidine can prevent the risk of airway obstruction associated with increasing the dose of dexmedetomidine while achieving the same favorable intubation scores.