Department of Pharmacy, Washington Regional Medical Center, 3215 N. North Hills Blvd, Fayetteville, AR 72703, USA.
J Thromb Thrombolysis. 2011 Oct;32(3):318-27. doi: 10.1007/s11239-011-0594-5.
Acutely ill medical patients are at significant risk of venous thromboembolism (VTE). Thromboprophylaxis can substantially reduce the incidence of VTE, but to be optimally effective must consist of the correct choice of agent, at an appropriate dose, and for sufficient duration. Increasing evidence suggests that VTE risk persists beyond the standard period of prophylaxis. Although there is evidence that extended-duration prophylaxis is beneficial in preventing late VTE complications in high-risk surgical patients, few data exist in medical patients. The recent EXCLAIM study demonstrated that, subsequent to a standard prophylaxis regimen of 10 ± 4 days with enoxaparin 40 mg once daily, extended-duration prophylaxis (28 ± 4 days) with enoxaparin reduced total VTE events compared with placebo: 2.5% versus 4.0%; (absolute risk difference -1.53%; 95.8% confidence interval [CI] -2.54 to -0.52), with parallel increases in major bleeding rates (0.8% vs. 0.3%; absolute risk difference 0.51%; 95% CI 0.12-0.89%). The reduction in total VTE was principally driven by a decrease in symptomatic deep-vein thrombosis (absolute risk difference -0.60%; 95.8% CI -1.00 to -0.19%). Favorable benefit-to-risk ratios were observed in certain high-risk patient groups: level 1 immobility, women, and age >75 years. In addition to their underlying medical condition, medical patients often have multiple risk factors, placing them at sustained risk of VTE. Extended-duration prophylaxis might be most relevant in such patients. The development of appropriate risk assessment tools could help identify medical patients at greatest risk of late VTE events who might benefit most from extended-duration prophylaxis.
急性重病患者存在发生静脉血栓栓塞症 (VTE) 的显著风险。血栓预防可以显著降低 VTE 的发生率，但要达到最佳效果，必须选择正确的药物、合适的剂量和足够的疗程。越来越多的证据表明，VTE 风险在标准预防期之外仍然存在。虽然有证据表明，在高风险手术患者中，延长预防时间可预防晚期 VTE 并发症，但在医学患者中，相关数据很少。最近的 EXCLAIM 研究表明，在依诺肝素 40mg 每日一次、10±4 天的标准预防疗程后，与安慰剂相比，依诺肝素 28±4 天的延长预防疗程可降低总 VTE 事件：2.5%比 4.0%；（绝对风险差异-1.53%；95.8%置信区间[-2.54 至-0.52]），大出血发生率也平行增加（0.8%比 0.3%；绝对风险差异 0.51%；95%置信区间 0.12-0.89%）。总 VTE 的减少主要是由于症状性深静脉血栓形成的减少（绝对风险差异-0.60%；95.8%置信区间-1.00 至-0.19%）。在某些高危患者群体中观察到有利的效益风险比：1 级活动受限、女性和年龄>75 岁。除了基础疾病外，医学患者通常还存在多种危险因素，使他们持续面临 VTE 的风险。延长预防时间可能对这些患者最相关。开发适当的风险评估工具可以帮助确定最有可能发生晚期 VTE 事件且最有可能从延长预防时间中获益的医学患者。
