A comparison of different doses of remifentanil and tracheal lidocaine on attenuation of cardiovascular responses to laryngoscopy and tracheal intubation

Background: The efficacy of remifentanil infusion versus tracheal lidocaine for attenuation of the cardiovascular responses to tracheal intubation has been previously reported. This study compared hemodynamic stability during anesthesia induction and intubation using tracheal lidocaine and remifentanil. Materials and Methods: The study included 90 patients that were scheduled for elective surgery under general anesthesia and randomly allocated to 3 treatment groups: remifentanil 1 µg kg-1 min-1 bolus over 30 s, followed by an infusion of 0.5 µg kg-1 min-1 (R1); remifentanil 0.5 µg kg-1 min-1 over 30 s and an infusion of 0.25 µg kg-1 min-1 (R2); tracheal lidocaine (TL) (10%, 1.5 ml) spray 3 min after anesthesia induction (TL). Then the laryngoscope was removed and 3 min later, laryngoscopic intubation was performed. Heart rate, systolic arterial pressure, diastolic arterial pressure, mean arterial pressure, and rate-pressure product (RPP) were measured before induction of anesthesia (baseline), immediately before endotracheal intubation, and 1, 3, and 5 min after endotracheal intubation. Results: Just before endotracheal intubation, systolic, diastolic, and mean arterial pressure, heart rate, and RPP were significantly lower than at baseline in the R1 and R2 groups (P < 0.05). One minute after endotracheal intubation, systolic, diastolic, and mean arterial pressure, and RPP were significantly higher in the TL group than in the R1 group (P < 0.05). Heart rate was significantly higher in the TL group than in the R1 group 1, 3, and 5 min after laryngoscopy (P < 0.05). Conclusion: For attenuation of chronotropic response to tracheal intubation, remifentanil bolus and infusion was more effective than tracheal lidocaine.