Effects Of Low Doses Of Epinephrine And Ephedrine On The Onset Time Of Cisatracurium And The Hemodynamic During The Induction Of Anesthesia In The Elderly Patients

Objective To study the effects of low doses of epinephrine and ephedrine on the onset of cisatracurium and the hemodynamic during the induction of anesthesia in elderly patients and to provide the basis for a more security induction of anesthesia in eldly patients.Methods 75 elderly patients undergoing elective knee or hip replacement under general anesthesia were randomly assigned to three groups: Epinephrine group(Ep, n=25), Ephedrine group(Ed, n=25)and Control group(C, n=25).After the induction of anesthesia with 3μg/kg of fentanyl and 2.5 mg/kg of propofol, patients were randomly assigned to receive either 0.06 ug/kg of epinephrine, 70 ug/kg of ephedrine or a saline placebo, and then 0.15 mg/kg of cisatracurium was administrated. The onset time of cisatracurium and the intubation condition were measured. The changes of the cardiac output,invasive blood pressure and heart rate were monitored before induction, which was defined as baseline, one minute before intubation, before intubation,after intubation,one minute, two minute and three minute after intubation.Results The onset time of cisatracurium in Ep group and Ed group were significantly shorter than that in C group(P < 0.01, 0.05 respectively), and the intubation conditions were significantly better than C group(P< 0.05). There was a significant decrease in cardiac output and blood pressure in C group(P < 0.05, 0.01 respectively)and a significant decrease in blood pressure in Ep group and Ed group(P < 0.01,0.05 respectively), nevertheless, no statistical difference in cardiac output in two groups(P > 0.05)after induction compared with baseline. The blood pressure and cardiac output in Ep group and Ed group were significantly higher than C group(P < 0.05)and the mean arterial pressure in Ed group was significantly higher than Ep group and C group(P < 0.05)after induction. The blood pressure in Ed group was still higher than Ep group and C group(P < 0.05,0.01 respectively)after intubation. There was a significant decrease in heart rate before intubation compared with baseline in Ep,Ed and C group(P < 0.01, 0.05 and 0.01 respectively)and the heart rate is increased after intubation in Ed group compared with baseline (p< 0.05), but no statistical difference among three groups(P > 0.05). The incidences of hypotention before intubation in Ep group and Ed group were significant lower than C group (P<0.05,0.01 respectively),and the incidences of postintubation hypertention in Ed group was higher than in Ep and C group(P < 0.05),there were no statistical difference between Ep group and C group(P> 0.05).Conclusions Both 0.06 ug/kg of epinephrine and 70 ug/kg of ephedrine can accelerate the onset time of cisatracurium and alleviate circulatory depression caused by propofol and improve intubating conditions during induction of general anesthesia in elderly patients. The epinephrine is much more suitable for the elderly patients due to the short duration and less change to aggravate post intubation hypertension.