Bispectral index-guided comparison of dexmedetomidine and fentanyl as an adjuvant with propofol to achieve an adequate depth for endotracheal intubation - A double-blind randomised controlled trial.

Background and aims: Laryngoscopy and tracheal intubation require an adequate depth of anaesthesia. The study's primary objective was to compare the time needed to achieve the bispectral index (BIS)-guided adequate depth of anaesthesia for endotracheal intubation using fentanyl and dexmedetomidine.

Methods: After institutional ethics committee clearance and written informed consent, this randomised study was conducted on 140 patients of either gender between 18 and 60 years who were scheduled for elective surgeries under general anaesthesia. Patients were randomised to intravenous dexmedetomidine 1 μg/kg (Group D) or fentanyl 2 μg/kg (Group F). The drugs were given as an intravenous infusion over 10 min before induction of anaesthesia. The primary outcome was the time required to achieve BIS 50. Normally distributed variables were compared using Student's t-test, and non-normally distributed variables were compared using the Mann-Whitney U test. Qualitative data were analysed using Chi-square/Fisher's exact test. A P value <0.05 was considered significant.

Results: The time to achieve BIS 50 was lesser in Group F, 1546 (27) as compared to Group D, 1558 (11) s [mean difference (95% confidence interval (CI) 12[5.11, 18.89]), P < 0.001]. Haemodynamic parameters were comparable at all time points between both the groups, except heart rate, which was significantly lower. Propofol consumption was significantly less in group D than in group F [125.9 (25.36) versus 157.3 (42.80) mg, respectively, mean difference (95% CI) 31.4 (-44.16 to -20.63) P < 0.001)].

Conclusion: Dexmedetomidine achieves BIS 50 faster and has a propofol-sparing effect as compared to fentanyl.