A prospective randomized controlled study comparing intravenous dexmedetomidine plus ketamine combination with intravenous dexmedetomidine alone for awake fibreoptic nasotracheal intubation

Background: The purpose of this study was to compare the efficacy and safety of dexmedetomidine versus dexmedetomidine and ketamine for sedation during awake fibreoptic intubation (FOI) in patients posted for elective surgeries. Ninety-eight American Society of Anesthesiologists Physical Status (ASA-PS) I-II patients with difficult airway and scheduled for elective surgeries were enrolled in this study after institutional ethics committee approval. Patients were randomly allocated into 2 groups, i.e. 49 patients in each group. Group D patients received 1 mu g/kg dexmedetomidine IV over 10 min in 100-mL normal saline followed by a continuous infusion at 0.5 mu g/kg/h till FOI and 5-mL normal saline followed by saline infusion. Group DK patients received 1 mu g/kg dexmedetomidine IV over 10 min in 100-mL normal saline. Further, they received IV ketamine 15 mg as a bolus of 5 mL, followed by continuous infusion of ketamine at 20 mg/h until the end of intubation. The primary objective was to compare the efficacy of the combination of IV dexmedetomidine and ketamine with IV dexmedetomidine alone as sedation for FOI. Vocal cord movement, sedation, coughing, facial grimace score, recall of procedure, and haemodynamics were also compared in both groups. Results: Demographic data, vocal cord movement, cough score, facial grimace score, total drugs used, hoarseness, sore throat and level of recall were comparable in both groups. Haemodynamics were significantly better in group DK at 2, 3, 4 and 5 min compared to group D. Conclusions: Addition of ketamine to dexmedetomidine did not improve intubating conditions, reduce cough or improve recall of FOI. However, patients remain sedated when ketamine was used with dexmedetomidine. The study was not registered prospectively in any clinical trial registry.