Collecting venous blood of pre-anesthesia(T0),1 hour(T1),3 hours(T2) after intubation and 4 hours(T3) after operation respectively,and the content of ET was then measured via radio immunoassay.

• 分别于麻醉诱导前、全麻插管后1h、3h、术后4h采静脉血,用放射免疫分析法测定内皮素含量。