Lai K N, Ho K, Li M, Szeto C C
Department of Medicine, Queen Mary Hospital, University of Hong Kong, Pokfulam.
Int J Artif Organs. 1998 Apr;21(4):196-200.
Low-molecular-weight (LMW) heparin has recently been used for anti-coagulation in maintenance hemodialysis. The LMW heparin was administered as a single bolus in hemodialysis that usually lasted for four hours or less. The regimen for administering LMW heparin in hemodialysis of longer duration (5 hours or more) is not well documented and manufacturers recommend a supplementary dose equivalent to one-quarter of the initial dose to be given at 4 hours after the commencement of hemodialysis. In this study, we explored whether administering a single dose of LMW heparin is feasible in hemodialysis of longer duration. Maintenance five-hour hemodialysis sessions were performed in nine uremic patients with two different heparin regimens: single dose of LMW heparin (nadroparin) 12,500 ICU AXa at the beginning of dialysis or a priming dose of nadroparin 10,000 ICU AXa at the beginning of dialysis followed by a supplementary dose of nadroparin 2,500 ICU AXa at the beginning of the fifth hour of dialysis. Clots in the airtraps or clotting of the dialyser were not observed in hemodialysis with the single dose heparin regimen. The anti-Xa activities at different time intervals during dialysis were above the therapeutic range of 0.5 U/ml except towards the end of the hemodialysis treatment. There was no difference between anti-Xa activities determined in dialysis sessions using two different regimens of LMW heparin at any individual time interval. The anti-thrombotic effect determined by the area under the time response curve for anti-Xa activity was comparable in the two LMW heparin regimens. Hence, our findings suggest a single bolus dose of LMW heparin (nadroparin) at 12,500 ICU AXa provides adequate, safe, and effective anti-coagulation for five-hour hemodialysis. This practice is convenient and avoids the necessity of administering a double dose of LMW heparin.
低分子量（LMW）肝素最近已用于维持性血液透析的抗凝治疗。在通常持续4小时或更短时间的血液透析中，LMW肝素以单次推注的方式给药。在持续时间较长（5小时或更长时间）的血液透析中给予LMW肝素的方案尚无充分记录，制造商建议在血液透析开始后4小时给予相当于初始剂量四分之一的补充剂量。在本研究中，我们探讨了在持续时间较长的血液透析中给予单剂量LMW肝素是否可行。对9例尿毒症患者进行了5小时的维持性血液透析，采用两种不同的肝素方案：透析开始时单次给予LMW肝素（那屈肝素）12,500国际单位抗Xa因子，或透析开始时给予那屈肝素首剂10,000国际单位抗Xa因子，然后在透析第5小时开始时给予那屈肝素补充剂量2,500国际单位抗Xa因子。在采用单剂量肝素方案的血液透析中，未观察到空气捕集器中的凝血块或透析器凝血。除血液透析治疗接近结束时外，透析期间不同时间间隔的抗Xa活性均高于0.5 U/ml的治疗范围。在任何单个时间间隔，使用两种不同LMW肝素方案的透析疗程中测定的抗Xa活性之间没有差异。两种LMW肝素方案中，通过抗Xa活性时间反应曲线下面积确定的抗血栓形成作用相当。因此，我们的研究结果表明，单剂量12,500国际单位抗Xa因子的LMW肝素（那屈肝素）可为5小时的血液透析提供充分、安全和有效的抗凝作用。这种做法很方便，避免了给予双倍剂量LMW肝素的必要性。
