体外循环不同血流方式与内脏白细胞隔离及肿瘤坏死因子形成的影响

The effect of physiologic pulsatile and nonpulsatile perfusion on viscera leukocyte sequestration and TNFa formation

目的旨在探讨体外循环致全身炎症反应的机理及探寻减轻或消除这种反应的措施。方法对２０例风湿性心脏瓣膜病人随机分为搏动（ＰＦ）组及非搏动（ＮＰＦ）组，于体外循环不同时点在上、下腔静脉采血，计数白细胞及测定肿瘤坏死因子（ＴＮＦα）。结果在ＮＰＦ组心脏复跳前下腔静脉血内白细胞显著低于上腔静脉（Ｐ＜００５）；在ＰＦ组生理性搏动血流实现后上下腔静脉血内白细胞无差异（Ｐ＞００５）。于体外循环期间两组血内ＴＮＦα均有升高，但以ＮＰＦ组明显，两者比较差异有显著性。结论体外循环非搏动血流具有内脏白细胞隔离效应，生理性搏动血流几乎无内脏白细胞隔离作用，引起ＴＮＦα增加变化不明显，具有减轻或消除体外循环后全身炎症反应作用。

Objective To explore the mechanism of inflammatory response to cardiopulmonary bypass by determining viscera (liver, intestine) leukocyte sequestration and tumor necrosis factor a (TNFa) formation during physiologic pulsatile and nonpulsatile perfusion.Methods Twenty patients who underwent heart valve (s) replacement were divided into pulsatile and nonpulsatile perfusion groups at random. Blood was serially sampled from vena cava inferior and superior at 6 time points for leukocyte count and the blood from oxygenators at 4 time points for tumor necrosis factor a detection. Leukocytes were counted by means of Technnikon H1 counter. One step “sandwich” enzyme immunoassay was used for the quantitative determination of TNFa in the plasma.Results The leukocytes were significantly lower (P<0 05) in blood from vena cava inferior than superior before heart beating during nonpulsatile perfusion. There were no differences of leukocytes between vena cave inferior and superior after physiologic pulsatile perfusion achievement ( P >0.05). TNFa was detected in both groups, but it was significantly higher after crossclamp removal and 10 minutes after heart beating in the nonpulsatile group than pulsatile group.Conclusion The results suggest that nonpulsatile perfusion, compared with pulsatile perfusion, can induce viscera leukocyte sequestration and increase cytokine formation, this may be an important factor resulting in systemic inflammatory response to cardiopulmonary bypass.