Lancet：间歇充气加压能有效降低脑卒中患者深静脉血栓发生的风险

深静脉栓塞是造成住院患者死亡和发病的一种常见的但可以避免的原因，在脑卒中患者中也是如此。在接受手术的患者中，间歇加压充气（IPC）能降低深静脉血栓发生的风险，但是目前还没有确实可靠的证据可以证明IPC对脑卒中患者具有同样的疗效。为了评估IPC能否有效降低脑卒中患者深静脉血栓发生的风险，来自CLOTS研究协作组的研究者们设计了相关研究，并将其研究结果发表在The Lancet 5月的在线期刊上。

CLOTS 3研究是一个多中心平行随机研究，该研究旨在评估在行动不便的患者中（必须在他人的帮助下才能步行至厕所的患者）采用IPC治疗的有效性。研究者所纳入的受试者是入院当天至入院3天内的患者，并采用中央随机系统将上述受试者按照1:1的比例随机分为2组，一组接受IPC治疗，另一组不接受IPC治疗。由一名不知道患者所接受的治疗方案的技术员在第7-10天对受试者行双下肢压缩多普勒超声（CDU）检查，如果可行的话，在入组后第25-30天再次对上述受试者性CDU检查。照料受试者的人和受试者自身知晓其所接受的治疗方案。研究者对受试者的随访直至6个月以确定受试者的生存率和之后所出现的有症状的深静脉血栓的发生情况。本研究的主要终点事件为在随机化分组的30天内，采用CDU筛查所发现的近端静脉内深静脉血栓发生情况或经由影像检查所证实的任何有症状的近端深静脉血栓。研究者采用按方案分析对研究结果进行分析。研究注册号ISRCTN93529999。

在2008年12月8日至2012年9月6日期间，从英国的94个中心内研究者共纳入了2876名受试者。所纳入的受试者基本为行动不便的脑卒中患者，其平均年龄为76岁（IQR 67-84岁）。在IPC组中的1438名受试者中有122人（8.5%）出现本研究的主要终点事件，而在非IPC组的1438名受试者中有174人（12.1%）出现本研究的主要终点事件，两组的绝对降低风险为3.6%（95%可信区间为1.4-5.8）。在排除了323名在达到主要终点事件之前就死亡的受试者以及41名没有接受任何CDU的受试者之后，调整后的OR为0.65（IPC组的1267名受试者中有122人，非IPC组的1245名受试者中有174人），两组差异具有显著统计学意义。在治疗后的30天内，在IPC组中有156人（11%）死亡，而在非IPC组中有189人（13%）死亡，两组差异不具有显著统计学意义（p=0.057）；在IPC组中有44人（3%）出现腿部皮肤破裂，在非IPC组中有20人（1%）出现皮肤破裂，两组差异具有显著统计学意义（p=0.002）；IPC组中有33人（3%）因跌倒而受伤，而在非IPC组中有24人（2%）因跌倒而受伤，两组差异不具有显著统计学意义（p=0.221）。

本研究结果指出，间歇充气加压疗法能有效降低脑卒中后行动不便的患者的深静脉血栓发生的风险，或能改善上述患者的生存情况。

Effectiveness of intermittent pneumatic compression in reduction of risk of deep vein thrombosis in patients who have had a stroke (CLOTS 3): a multicentre randomised controlled trial
Background
Venous thromboembolism is a common, potentially avoidable cause of death and morbidity in patients in hospital, including those with stroke. In surgical patients, intermittent pneumatic compression (IPC) reduces the risk of deep vein thrombosis (DVT), but no reliable evidence exists about its effectiveness in patients who have had a stroke. We assessed the effectiveness of IPC to reduce the risk of DVT in patients who have had a stroke.
Methods
The CLOTS 3 trial is a multicentre parallel group randomised trial assessing IPC in immobile patients (ie, who cannot walk to the toilet without the help of another person) with acute stroke. We enrolled patients from day 0 to day 3 of admission and allocated them via a central randomisation system (ratio 1:1) to receive either IPC or no IPC. A technician who was masked to treatment allocation did a compression duplex ultrasound (CDU) of both legs at 7—10 days and, wherever practical, at 25—30 days after enrolment. Caregivers and patients were not masked to treatment assignment. Patients were followed up for 6 months to determine survival and later symptomatic venous thromboembolism. The primary outcome was a DVT in the proximal veins detected on a screening CDU or any symptomatic DVT in the proximal veins, confirmed on imaging, within 30 days of randomisation. Patients were analysed according to their treatment allocation. Trial registration: ISRCTN93529999.
Findings
Between Dec 8, 2008, and Sept 6, 2012, 2876 patients were enrolled in 94 centres in the UK. The included patients were broadly representative of immobile stroke patients admitted to hospital and had a median age of 76 years (IQR 67—84). The primary outcome occurred in 122 (8·5%) of 1438 patients allocated IPC and 174 (12·1%) of 1438 patients allocated no IPC; an absolute reduction in risk of 3·6% (95% CI 1·4—5·8). Excluding the 323 patients who died before any primary outcome and 41 without any screening CDU, the adjusted OR for the comparison of 122 of 1267 patients vs 174 of 1245 patients was 0·65 (95% CI 0·51—0·84; p=0·001). Deaths in the treatment period occurred in 156 (11%) patients allocated IPC and 189 (13%) patients allocated no IPC died within the 30 days of treatment period (p=0·057); skin breaks on the legs were reported in 44 (3%) patients allocated IPC and in 20 (1%) patients allocated IPC (p=0·002); falls with injury were reported in 33 (2%) patients in the IPC group and in 24 (2%) patients in the no-IPC group (p=0·221).
Interpretation
IPC is an effective method of reducing the risk of DVT and possibly improving survival in a wide variety of patients who are immobile after stroke.