Effects of different carrier gases on the performance of the Ohmeda Tec6 desflurane vaporizer / 中华麻醉学杂志

ABSTRACT

Objective To investigate the effects of different carrier gases on the performance of Ohmeda Tec6 desflurane vaporizer. Methods Forty ASA Ⅰ-Ⅱpatients undergoing surgery under general anesthesia with desflurane were enrolled in this study. The age ranged from 37-67 years(mean age 60 years) and body weight from 46-75kg(mean body weight 59.6kg). After induction of anesthesia and tracheal intubation anesthesia was maintained with desflurane. The fresh gas flow(FGF) rate of Ohmeda 210 anesthesia machine was maintained at 5.0L/min and vaporizer dial was set at 6% or 3% . The inspired Concentration of desflurane(FIdes) was analyzed by a Datex ULT-V Capnomac. Five different carrier gases were used(1) 100%O2;(2) 70% O2 + 30%N2O;(3) 30% O2 + 70%N2O;(4) 70% O2 + 30% N2;(5)30% O2 + 70% N2. There was an interval of 10 mm between two different carrier gases and 40 samples were analyzed for each carrier gas. Results Different carrier gases markedly affected the outflow of Tec6 desflurane vaporizer. The inspired concentration of desflurane decreased significantly with the decrease in oxygen concentration of FGF. Nitrous oxide affected FIdes more significantly than nitrogen at the same concentration of oxygen. Conclusions The oxygen and nitrous oxide concentration of carrier gas affects the inspired concentration of desflurane when Ohmeda Tec6 desflurane vaporized is used.