Determination of sevoflurane minimum alveolar concentration in newborn and adult rats / 临床麻醉学杂志

ABSTRACT

Objective To measure and compare sevoflurane minimum alveolar concentration (MAC)in newborn and adult rats.Methods The rats were divided into newborn rat (6-8 days) group (25 cases)and adult rat (8-10 weeks)group (25 cases).All rats were settled in the self-made device for anesthesia with inhaled sevoflurane,and the tails of rats were exposed out of the device. Sevoflurane was given via an anesthesia machine.Up-and-down method and clamping tail stimulus were applied to measure the MAC values of sevoflurane in the two groups.1.5% of sevoflurane was set as the initial concentration,and± 0.2% as adjustable gradient.A positive or negative response was judged by clamping tail stimulus in a 20 minutes interval.The mean MAC value of all rats in each group was defined as the MAC value.Results The MAC value of newborn rats was (2.58 ± 0.1 1)%,and the MAC value of adult rats was (2.32 ±0.13)%.A significant difference was found between the two groups (P <0.01).Conclusion The MAC value of newborn rats was much higher than that of adult rats.Newborn rats need a higher concentration of sevoflurane at the same depth of anesthesia when compared with adult rats.