Kovacs M J, Weir K, MacKinnon K, Keeney M, Brien W F, Cruickshank M K
Department of Medicine, University of Western Ontario, Canada.
Thromb Res. 1998 Aug 1;91(3):137-42. doi: 10.1016/s0049-3848(98)00083-8.
Enoxaparin after joint arthroplasty is effective prophylaxis against venous thromboembolism. This is usually given as a fixed dose without monitoring of anti-Xa levels. This study assesses the relationship between trough anti-Xa levels, body weight, and venous thromboembolism. Consenting patients at three institutions were treated with Enoxaparin 30 mg subcutaneously bis in die postoperatively until discharge. Chromogenic anti-Xa levels were measured on the fifth postoperative day by the method of Stachrome (Diagnostica Stago). All patients had bilateral compression doppler ultrasonography on day 10 or discharge and were followed for 12 weeks for evidence of venous thromboembolism. Eleven patients developed objectively confirmed venous thromboembolism during the study. In this study, there was poor correlation between weight and anti-Xa levels. In addition, body weight and anti-Xa levels of patients who developed venous thromboembolism were compared to those who did not and there were no significant differences between the two groups. In conclusion, this study shows that there is poor correlation of trough anti-Xa levels with body weight. Recognizing the low overall event rate this study does not support the need to monitor anti-Xa levels or adjusting the dose according to weight.
关节置换术后使用依诺肝素是预防静脉血栓栓塞的有效方法。通常以固定剂量给药，无需监测抗Xa水平。本研究评估谷值抗Xa水平、体重与静脉血栓栓塞之间的关系。三个机构中同意参与研究的患者术后每日两次皮下注射30mg依诺肝素，直至出院。术后第5天采用Stachrome法（Diagnostica Stago）测定显色抗Xa水平。所有患者在第10天或出院时接受双侧压迫式多普勒超声检查，并随访12周以观察静脉血栓栓塞迹象。研究期间有11例患者发生了经客观证实的静脉血栓栓塞。本研究中，体重与抗Xa水平之间的相关性较差。此外，对发生静脉血栓栓塞的患者与未发生者的体重及抗Xa水平进行了比较，两组之间无显著差异。总之，本研究表明谷值抗Xa水平与体重之间的相关性较差。鉴于总体事件发生率较低，本研究不支持监测抗Xa水平或根据体重调整剂量的必要性。
