安氟醚对肺血分流的影响

The effect of enflurane on pulmonary shunt: a placebo--controlled Clinical study.

２０例行上腹部手术忠者，随机分为实验组和对照组，每组１０例。实验组在硬膜外阻滞下，吸入６０％Ｎ２Ｏ－４０％Ｏ２基础上吸入１．６％安氟醚。分别在麻醉前、插管后０．５小时，吸安氟醚１小时、２小时，停安氟醚０．５小时，拔管后吸空气１小时取动脉及右心室混合静脉血进行血气分析，计算分流量。结果表明实验组在吸安氟醚后肺内分流增加，明显高于对照组（Ｐ＜０．０５）。结论是安氟醚使肺内分流增加，并持续至手术后一段时间，可导致低氧血症，应予吸氧预防。

To estimate the effect of enflurane on pulmonary shunt (PS) ; twenty patients, ASA grade to ,aged between 25 and 60 years,scheduled to undergo upper abdominal surgery,were randomly divided into group I(n= 10) and group (n= 10). All of the subjets inhaled the mixture of 60% nitrous oxide and 40% oxygen (MNOO),afterwards the inhaled mixture of group I was combined with 1. 6% enflurane and that of group as the control was not. The blood samples in artery and right ventricle were taken to analyse the blood gas,before anesthesia,at 30 min after the inhalatin of MNOO,one and two hours following inhalation of enflurane, 30 min subsequent to withdrawal of enflurane and one hour posterior to extubation and breathing air respectively. Qs/Qt,the ratio of pulmonary shunt volume to cardiac output,serving as the parameter indicating PS,was caculated according to the values of the above blood gas. The results showed that following the inhalation combined with enflurane in group I,Qs/Qt level increased significantly (P<0. 01 ),after the withdrawal of enflurane for 30 min or breathing air for an hour,it remained higher level than baseline in spite of decreasing markedly (P<0. 05 ). During the procedures since the inhalation of enflurane, Qs/Qt value rose dramatically in group I,as compared correspondinghy with the control levels in group (P<0. 05). It is Concluded that enflurane may elevate PS, and its withdrawal can not return PS to normal in short duration,so it is necessary after enflurane anesthesia to apply continuously inhaling oxygen to the patients,especlally to those with respiratory diseases and the elderly.