The effects of esmolol on the bispectral index and the hemodynamic responses of intubation-extubation during operations of the middle ear

The aim of this, the effects of esmolol which is a short- activing cardioselective beta-blocker, on the Bispectral index values (BIS) and the hemodynamic responses of laryngoscopy, endotracheal intubation -extubation were investigated.The study was consisted of 40 patients with an American Society of Anesthesiology (ASA) physical status of I-II were between 20-40 years of age and randomly divided into two groups. Following Institutional Ethical Committee approval, this clinical prospective randomized placebo controlled study was planned.None of the patients used premedication. The ECG in DII lead, peripheral oxygen saturation (SpO2), end ?tidal CO2 (EtCO2), noninvasive blood pressures and BIS of the patients who were taken to the operating room for operation were measured.After the monitorization of the patients, the baseline values were measured in the operation room. Systolic blood pressures, diastolic blood pressures, mean arterial pressures, heart rates, peripheral oxygen saturations were measured after a bolus of esmolol in Group E and a saline bolus in the placebo group ( Group K) immediately on this time ( before induction ), after extubation, 1 st, 2nd, 3rd, 4th and 5 th in minutes, after skin incision, 1 st, 3rd and 5 th in minutes, end of the anesthesia, extubation period, exiting from operation room and Aldrete Score ?9 in recovery room at this time. The BIS values of the patients after induction, intubation, operation and extubation on recovery room were measured.Esmolol (before induction (1 mg/kg ) and extubation (0,5 mg/kg)) was given to Group E, which was selected according to protocol. An aqual volume of isotonic saline iv bolus was given to the control group (Grup K).The application of 1 mg/kg dose of esmolol before the intubation effected on the BIS and increased heart rates and mean arterial blood pressures. The application of 0,5 mg/kg dose of esmolol before extubation suppressed significantly the increased heart rates and the mean arterial blood pressures.According to this study undesirable hemodynamic changes due to laryngoscopy intubation and extubation can effectively prevented by application of 0,5-1 mg/kg dose of esmolol during middle ear surgery.