Xa因子抑制法动态测定体外循环围手术期血浆肝素浓度的应用研究

目的 动态测定体外循环（CPB）围术期患者血浆肝素浓度，探讨检测结果在指导临床医生合理使用鱼精蛋白拮抗肝素作用的临床意义。方法 采用Xa因子抑制示检测25例在CPB下行心瓣膜置换术的风心病患者在CPB前，肝素化5min及结束时和鱼精蛋白拮抗肝素后10min，1h及5h共6个时点血浆肝素浓度。结果 CPB前，患者肝素水平0.45U/ml，CPB术肝素化5min及结束时，肝素浓度分别为13.16U/ml和11.06U/ml，与各时点比较均有显著性差异（P＜0．05）；鱼精蛋白拮抗后10min，血浆肝素迅速回到CPB前水平，且鱼精蛋白结抗后3个时点肝素浓度间及与CPB术前比较均无显著性差异（P＞0．05）；Xa因子抑制法测定的肝素标准曲线批间变异高值为11．65％，低值为0．36％。结论 Xa因子抑制法测定血浆肝素浓度重复性好，精密度高，该法在围CPB术的临床应用显示，CPB术结束时各患者血浆肝素浓度是确定其自身鱼精蛋白用量的参比标准。

Factor Xa lnhibitory Assay to Detect Plasma Heparin Concentrations During and after Cardiopulmonary Bypass

Objective For establishment and application of Xa Factor Inhibitory Assay to detect plasma heparin concentrations during and after cardiopulmonary bypass (CPB) and to evaluate the treatment with low dose protamine reversal of heparin. Methods Venous blood samples were drawn from 25 patients with rheumatic valvular disease undergoing valvular replacement at different points (before CPB,after 5 min of heparinization,at termination of CPB, after 10 min,1 hr and 5 hr of protamine reversal of heparin), and the plasma heparin concentrations were detected. Results The mean of plasma heparin concentration was the highest (13.16 U/ml) after 5 min of heparinization. At termination of CPB, it decreased (11.06 U/ml) and was significantly different from the concentrations at other points ( P <0.05). After 10 min of low dose protamine reversal of heparin, the heparin concentration (0.45 U/ml) decreased to the same as that before CPB and continued to be stable at 1 hr and 5 hr; there was no significant difference in heparin concentration between these 4 points ( P >0.05). The highest batch CV in standard curves was 11.65%; the lowest was 0.37%. Conclusion Factor Xa Inhibitory Assay is of good accuracy and repetition. The results from its clinical application demonstrated that the plasma heparin concentration of the patient at termination of CPB should be used for reference in determining the dose level of protamine for that every patient subjected to CPB.