Evaluation of Mexiletine Effect on Bispectral Index Changes and Hemodynamic Responses to Endotracheal Intubation and During General Anesthesia

Plaryngoscopy and tracheal intubation increase not only blood pressure and heart rate but also Bispectral Index (BIS) of the patients. In this study, hemodynamic and BIS changes were surveyed after tracheal intubation and during general anesthesia followed by mexiletine prescription. In this study, 50 patients aged between 20 and 60 who were candidates for orthopedic surgery of the upper limbs were surveyed. They were divided in two groups randomly. Two hours before induction of anesthesia, case and control groups received mexiletine 200 mg as capsule and oral placebo, respectively. Systolic and diastolic blood pressures, heart rate, and BIS of both groups were compared before induction and intubation; 1,3 and 10 minutes after intubation; and immediately, 15, 30, 45, and 60 minutes after surgical incision. There was not any significant differences in systolic and diastolic pressures of the two groups. The heart rate was lower in mexiletine group compared to control group, 30 minutes after surgical incision and immediately after extubation (P<0.05). BIS was significantly more in mexiletine groupcompared to control group (p<0/05). It was revealed that the hemodynamic changes after laryngoscopy and during general anesthesia were significantly lower in mexiletine group compared to the control group. It`s suggested that the prescription of this drug leads to the increase of BIS after intubation and during general anesthesia.