Effect of different doses of remifentanil on the cardiovascular response after endotracheal intubation: a randomized double-blind study.

Laryngoscopy and endotracheal intubation (EI) often provoke a marked sympathetic response, which leads to tachycardia and hypertension. The aim of this study was to investigate the effect of different doses of remifentanil on the cardiovascular response to laryngoscopy and EI.100 patients were included in this randomized study. The participants were divided into four groups of 25 patients each. The patients in the control group did not receive remifentanil. The patients from other three groups received remifentanil prior to induction of anesthesia at doses of 0.5 µg/kg, 1 µg/kg, and 1.5 µg/kg. Hemodynamic parameters were measured before and after administration of remifentanil, after induction of anesthesia and one minute after EI.After administration of remifentanil and induction of anesthesia, a decrease in arterial pressure and heart rate occurred in most patients. After EI, an increase in arterial pressure and heart rate was observed in most patients. The largest increase was recorded in the group of patients who did not receive remifentanil. The best hemodynamic response was observed in patients who received 1 and 1.5 µg/kg of remifentanil.Remifentanil at the doses of 1-1.5 µg/kg is absolutely safe for co-induction of anesthesia with thiopental. Such dosing regimen provides optimal conditions for reducing hemodynamic response to laryngoscopy and EI.