Efficacy of dexmedetomidine in attenuating pressor response to laryngoscopy and endotracheal intubation under bispectral index controlled anesthesia: a prospective randomized double-blinded study

Background Laryngoscopy and endotracheal intubation may lead to a remarkable hemodynamic pressor response. Dexmedetomidine, an a(2)-adrenergic receptor agonist, can be effectively used to attenuate this pressor effect. This study was aimed to compare the efficacy of two different doses of dexmedetomidine (0.5 mu g/kg and 1.0 mu g/kg) in attenuation of hemodynamic pressor response to largyngoscopy and endotracheal intubation under bispectral index (BIS) monitoring. One hundred twenty adult patients with American Society of Anesthesiologists (ASA) physical status I or II posted for various elective surgeries under general anesthesia were enrolled to receive an intravenous (IV) infusion of dexmedetomidine 0.5 mu g/kg (group D1; n = 40), 1.0 mu g/kg (group D2; n = 40) or normal saline over 15 min (group C; n = 40). The primary outcome measure was to assess the hemodynamic changes while the secondary outcome measures were to assess sedation, dose of propofol required for induction and side effects. Results The mean HR, SBP, DBP, and MAP remained significantly lower in both dexmedetomidine groups as compared to control group after study drug infusion, after induction, at and after intubation (P < 0.05). Group D2 also had significantly lower mean HR, SBP, DBP, and MAP in comparison to group D1 (P < 0.05). The induction dose of propofol was significantly less in dexmedetomidine groups as compared to control group (P < 0.05). Ramsay sedation scale (RSS) score was found to be significantly more in both groups D1 and D2 after study drug infusion (P<0.001). No significant difference was noted in incidence of side effects (P = 0.907). Conclusions Dexmedetomidine (0.5 mu g/kg and 1.0 mu g/kg) was found to be effective in attenuating the hemodynamic pressor response to laryngoscopy and endotracheal intubation with BIS monitoring.