低温体外循环阻断主动脉期间氧代谢及乳酸的变化

CHANGES OF OXYGEN METABOLISM AND LACTATE DURING HYPOTHERMIC CARDIOPULMONARY BYPASS WITH AORTIC CROSS CLAMPING

观察了１５例心内直视手术病人在低温体外循环主动脉阻断后１ｍｉｎ，体温最低时、开放主动脉前１ｍｉｎ的氧供（ＤＯ＿２）、氧耗（ＶＯ＿２）、氧摄取率（ＥＲＯ＿２）及动脉血乳酸（ＬＡ）含量的变化。结果显示：在整个主动脉阻断期间ＤＯ＿２无明显变化；体温最低时ＶＯ＿２，ＥＲＯ＿２显著降低，而ＬＡ含量显著增高；开放主动脉前１ｍｉｎ与主动脉阻断后１ｍｉｎ比较，鼻咽温无明显变化，直肠温显著降低，而ＶＯ＿２，ＥＲＯ＿２及ＬＡ含量显著增高。

e observed the changes of oxygen delivery(DO2),oxygen consumption(VO2),oxygen ex-traction rate(ERO2)and plasma lactate(LA)during hypothermic cardiopulmonary bypass(CPB)with aortic cross clamping in 15 patients undergoing heart surgery. Results:There was nosignificant difference in DO2.VO2, ERO2 decreased and the LA increased significantly at the low-est temperature. One minute before the relief from aortic clamping was compared with 1 minuteafter clamping aortic artery:there was no significant difference in nasopharynged temperature,the rectal temperature decreased significantly,while VO2, ERO2 and LA increased significantly.Conclusion:There was tissue hypoxia at the lowest temperature during hypothermic CPB withaortic cross clamping because tissue oxygen extraction was lower than tissue oxygen demand.Itis important to increase DO2 in order to fulfill the tissue oxygen demand during rewarming.