The Effect Of Menstrual Cycle On The Dose Of Propofol In Induction Of General Anesthesia

Background:In recent years, growing attention has been drawn to gender difference in the anesthetic pharmacokinetics and pharmacodynamics. There were few studies on comparing drugs variations in gender, which resulted in the lack of pharmacological data in gender difference. Estrogen and progesterone take on a fluctuating change in the reproductive cycle, while progesterone and its metabolites have sedative, anxiolytic, anticonvulsant and anesthetic effects. Fear of air pollution of inhalation anesthesia, the proportion of total intravenous anesthesia is going up year by year. However, the relationship between the female menstrual cycle and the dose of propofol in induction has not been reported yet. In the current study, we selected women at reproductive age undergo laparoscopic surgery under general anesthesia to compair the effect of different menstrual cycle on the dose of propofol in induction.Objective:To observe the effect of menstrual cycle on the dose of propofol in induction of general anesthesia. Method:According to the level of estradiol and progesterone, sixty patients aged 20-40 years scheduled for laparoscope surgery were divided into two groups:the follicular group and the luteal group. Propofol given with target controlled infusion system (using pharmacokinetic parameters reported by Marsh) was started by Ct=1.5ug/ml, added 0.5ug/ml per 30's till the value of BIS at 50. MAP, HR, and BIS were continuously monitored during the study. The plasma concentration of propofol was recorded at T1 (loss of eyelash reflex), T2(the value of BIS below 50) and T3(recovery of anesthesia). The total requirments of propofol were calculated.Result:The plasma concentration of propofol in the follicular group was significantly larger than in the luteal group at T1 and T2 (P<0.05). But there were no difference between two groups at T3 (P>0.05). The total requirments of propofol in the follicular group (106.3±13.3mg) were significantly larger than in the luteal group (89.7±12.2mg) (P<0.05).Conclusion:High progesterone levels during the luteal phase might be the cause of decreased propofol requirement in induction of general anesthesia.