Hull R D, Pineo G F, Francis C, Bergqvist D, Fellenius C, Soderberg K, Holmqvist A, Mant M, Dear R, Baylis B, Mah A, Brant R
Thrombosis Research Unit, 601 South Tower, Foothills Hospital, 1403-29 Street NW, Calgary, Alberta, Canada T2N 2T9.
Arch Intern Med. 2000 Jul 24;160(14):2208-15. doi: 10.1001/archinte.160.14.2208.
No randomized trials have directly evaluated the need for extended out-of-hospital thromboprophylaxis for patients who have hip arthroplasty in the United States or Canada. The uncertainty as to the need for extended prophylaxis in North American patients is complicated by early hospital discharge, resulting in a short thromboprophylaxis interval.
To resolve this uncertainty, we performed a randomized double-blind trial in 569 patients who underwent hip arthroplasty comparing the use of dalteparin sodium started immediately before surgery or early after surgery and extended out-of-hospital to an overall interval of 35 days with the use of warfarin sodium in-hospital and placebo out-of-hospital.
For patients with interpretable venograms in the preoperative, postoperative, and combined dalteparin groups, new proximal vein thrombosis out-of-hospital was observed in 1.3%, 0. 7% (P =.04), and 1.0% (P =.02) of patients, respectively, compared with 4.8% in the in-hospital warfarin/out-of-hospital placebo group. The respective overall cumulative frequencies of all deep vein thrombosis were 30 (17.2%) of 174 patients (P<.001), 38 (22.2%) of 171 (P =.003), and 68 (19.7%) of 345 (P<.001) in the dalteparin groups compared with 69 (36.7%) of 188 for the in-hospital warfarin/out-of-hospital placebo group. For proximal deep vein thrombosis, the respective frequencies were 5 (3.1%) of 162 (P =.02), 3 (2.0%) of 151 (P =.007), and 8 (2.6%) of 313 (P =.002) compared with 14 (9.2%) of 153. No major bleeding occurred during the extended prophylaxis interval.
Extended dalteparin prophylaxis resulted in significantly lower frequencies of deep vein thrombosis compared with in-hospital warfarin therapy. Despite in-hospital thromboprophylaxis, patients having hip arthroplasty in the United States and Canada remain at moderate risk out-of-hospital. The number needed to treat provides a public health focus; only 24 to 28 patients require extended prophylaxis to prevent 1 new out-of-hospital proximal vein thrombosis. Recent studies demonstrate that asymptomatic deep vein thrombi cause the postphlebitic syndrome; thus, extended out-of-hospital prophylaxis will lessen the burden to both the patient and society.
在美国或加拿大，尚无随机试验直接评估髋关节置换术后患者延长院外血栓预防治疗的必要性。北美患者延长预防治疗必要性的不确定性因早期出院而变得复杂，这导致血栓预防治疗间隔时间较短。
为解决这一不确定性，我们对569例行髋关节置换术的患者进行了一项随机双盲试验，比较术前或术后立即开始使用达肝素钠并延长至院外共35天的方案与院内使用华法林钠及院外使用安慰剂的方案。
在术前、术后及联合使用达肝素钠组中，可解释静脉造影的患者中，院外新发近端静脉血栓形成的发生率分别为1.3%、0.7%（P = 0.04）和1.0%（P = 0.02），而院内使用华法林钠/院外使用安慰剂组为4.8%。达肝素钠组所有深静脉血栓形成的累计总发生率分别为174例患者中的30例（17.2%）（P<0.001）、171例中的38例（22.2%）（P = 0.003）和345例中的68例（19.7%）（P<0.001），而院内使用华法林钠/院外使用安慰剂组为188例中的69例（36.7%）。对于近端深静脉血栓形成，发生率分别为162例中的5例（3.1%）（P = 0.02）、151例中的3例（2.0%）（P = 0.007）和313例中的8例（2.6%）（P = 0.002），而153例中有14例（9.2%）。在延长预防治疗期间未发生严重出血。
与院内华法林治疗相比，延长达肝素钠预防治疗可显著降低深静脉血栓形成的发生率。尽管进行了院内血栓预防治疗，但在美国和加拿大行髋关节置换术的患者院外仍处于中度风险。需治疗人数为公共卫生重点提供了依据；仅24至28例患者需要延长预防治疗以预防1例新的院外近端静脉血栓形成。近期研究表明无症状深静脉血栓会导致血栓形成后综合征；因此，延长院外预防治疗将减轻患者和社会的负担。
