Efficacy of dexmedetomidine versus remifentanil to blunt the hemodynamic response to laryngoscopy and orotracheal intubation: a randomized clinical trial.

The study aims to compare the efficacy of dexmedetomidine (DEX) vs . remifentanil (REM) to blunt the hemodynamic response to laryngoscopy and orotracheal intubation. Enrolled in a double-blind clinical trial, 124 patients undergoing elective surgery under general anesthesia at Amirkabir Hospital (Arak, Iran), were assigned into four groups equally (31 patients in each group), DEX, REM, DEX-REM, and normal saline (NS), who received intravenous DEX (1 µg/kg), REM (1 µg/kg), their equal mixture (each 0.5 µg/kg, 1 minute before tracheal intubation), and NS, respectively. Then, blood pressure (BP), heart rate (HR), and arterial oxygen saturation (SaO2 ) were measured on arrival to the operating room, 1 minute before laryngoscopy and tracheal intubation, immediately after intubation, and afterwards every 5 to 15 minutes, and finally the data were analyzed using SPSS 18.0. The groups were same regarding to age, sex and baseline hemodynamic variables including mean of BP ( P = 0.157), HR ( P = 0.105) and SaO2 ( P = 0.366). Tukey post-hoc test showed that there DEX, REM, and a DEX + REM groups was same regarding to MBP and HR, but these hemodynamic responses were higher in NS group than other groups at all time after laryngoscopy and intubation ( P < 0.05). Moreover, repeated measure test showed a decreasing trend in MBP and HR in three intervention groups at all time after intubation ( P > 0.05). A DEX/REM mixture had the lowest BP and three intervention groups had lower HR than the NS group. A mixture of the drugs used seems to lead to not only a prevented increase in HR and BP during laryngoscopy but also a decreased BP and HR. This study was registered in Iranian Registry Clinical Center with the registration No. IRCT2016092722254N1.