麻醉药在低流量紧闭麻醉环路内分布的实验研究

Distribution of volatile anesthetics within closed circuit system in low-flow.

对低流量紧闭麻醉环路内注药的分布，以及环路外挥发器释出药物及其环路内稀释进行实验研究。结果显示，吸入段注入 １ｍｌ三种含氟麻醉药液体产生较高的吸入浓度峰值，均在 １％或更多，呼出段注药２ｍｌ则不然，最高不过１．７％，但可控性差。注药１ｍｌ后３０分，环路内橡皮和塑料对麻醉药的吸收以安氟醚最大（３０％），而新鲜钠石灰对麻醉药的摄取则是七氟醚最多（６２％）。环路外挥发器在５００ｍｌ／ｍｉｎ的低流量下，开至刻度“５”，经稀释后的吸入浓度上升缓慢，５分时安氟醚的吸入浓度仍不足１％，难以适应麻醉诱导的需要。

Vaporization of liquid volatile anesthetics and their followup distribution on a conventional anesthetic machine were studied, through the injection into a closed circuit, as well as enflurane delivery with the out-of - cir cuit specified vaporizer. The result were as follows: (1) an inspired peak concentration of 4% or more appeared after injection 1 ml of the three anesthetics in inspiratory limb, but less than 1. 7% when injected 2 ml in expiratory. Nevertheless, both were difficult to control ; (2)at 30 min after 1 ml injection, absorption by rubber and plastic was most pro nounced in enflurane (30% ) ; while the uptake of sevoflurane by fresh soda lime denotes the highest (62 % ); (3)in fresh gas flow of 500ml/ min passing 5 min with the out-of-circuit vaporizer dialed at'5', the inspired concentration obtained below 1% was much less than that demanded for induction.