RESUMO
The present study was conducted on 20 controlled hypertensive adult patients. They all received general anesthesia for elective surgery and dexmedetomidine infusion for 5 minutes before endotracheal intubation and for 10 minutes thereafter. It was found out that there was a significant mild reduction in systolic blood pressure, mean heart rate, and rate pressure product after start of infusion, P=0.01, 0.05, and 0.01, respectively. After intubation, there were insignificant changes in systolic blood pressure [P=0.05] and heart rate showed mild significant increase at 1, 2, and 4 minutes with back to normal values at 6, 8, and 10 minutes. Rate pressure products also showed insignificant increase at 2, 4, and 6 minutes and back to normal at 6, 8 and 10 minutes. Epinephrine plasma level showed insignificant change after 10 minutes of intubation from baseline value 79.5 +/- 21 Vs. 76.8 +/- 18 pg/ml [P=0.01], while norepinephrine level was 419 +/- 48 pg/ml as baseline Vs. 428 +/- 51 pg/ml at 10 minutes after intubation with also mild insignificant change. The total dose of propofol used for induction of anesthesia was less than calculated as evidenced by loss of eyelash reflex and apnea with a mean value of 159 mg [1.54 mg/kg Bwt.] indicating that dexmedetomidine infusion before induction significantly reduced the dose of propofol needed for induction of anesthesia