NHS Blood & Transplant/Oxford Radcliffe Hospitals Trust, Oxford, United Kingdom.
Transfus Med Rev. 2010 Jul;24(3):163-71. doi: 10.1016/j.tmrv.2009.11.002.
Although considerable advances have been made in many aspects of platelet transfusion therapy in the last 30 years, some areas continue to provoke debate, including the use of prophylactic platelet transfusions for the prevention of thrombocytopenic bleeding in patients with bone marrow failure. We have designed a randomized controlled trial to compare prophylactic platelet use with a threshold of a platelet count of 10 x 10(9)/L with no prophylaxis in adult thrombocytopenic patients with hematologic malignancies. The trial question is whether a no-prophylactic policy for the use of platelet transfusions in patients with hematologic malignancies is not inferior to a threshold prophylactic policy at 10 x 10(9)/L, for bleeding at World Health Organization (WHO) grade 2, 3, or 4, up to 30 days from randomization. The primary outcome measure is the proportion of patients who have a significant clinical bleed, defined as WHO grade 2 or higher up to 30 days from randomization. Subsidiary clinical outcome measures include time to first bleed and a descriptive analysis of all severe bleeds. A bleeding assessment form is completed daily for all study subjects until day 30 from randomization. Minor modifications were made to the definitions at WHO grades 1 and 2 for petechiae and duration of nose bleeds, after piloting of the bleeding assessment forms. This study has been designed as a 2-stage randomized trial with an interim analysis planned after a minimum of 100 patients had been randomized and had completed their period of observation. Patients have initially been enrolled through 3 United Kingdom hematology centers. The interim analysis has been completed, and the results have confirmed a final sample size of 600 patients. Recruitment is now being extended to other centers in United Kingdom and Australia. Local research nurses are not blinded to treatment allocation, but a number of measures to reduce risk of assessment bias include repeated education around standard operating procedures, common definitions, and duplication of assessments. The expected completion date for the 5-year study is December 2011.
尽管在过去的 30 年中，血小板输注治疗在许多方面都取得了相当大的进展，但仍有一些领域继续引发争议，包括预防性血小板输注用于预防骨髓衰竭患者的血小板减少性出血。我们设计了一项随机对照试验，比较预防性血小板输注与血小板计数阈值为 10×10(9)/L 且无预防性治疗的方案，用于治疗患有血液恶性肿瘤的血小板减少症成人患者。该试验的问题是，对于血液恶性肿瘤患者，不进行预防性血小板输注的策略是否不比血小板计数阈值为 10×10(9)/L 的策略差，对于随机分组后 30 天内的世界卫生组织（WHO）分级 2、3 或 4 级出血。主要结局指标是发生显著临床出血的患者比例，定义为随机分组后 30 天内的 WHO 分级 2 级或更高。次要临床结局指标包括首次出血时间和所有严重出血的描述性分析。所有研究对象在随机分组后 30 天内每天填写出血评估表。在对出血评估表进行试点后，对 WHO 分级 1 和 2 的瘀斑和鼻出血持续时间的定义进行了轻微修改。该研究设计为 2 期随机试验，计划在至少 100 例患者随机分组并完成观察期后进行中期分析。患者最初通过英国的 3 个血液学中心招募。中期分析已经完成，结果证实最终样本量为 600 例患者。目前正在将招募范围扩大到英国和澳大利亚的其他中心。当地的研究护士未对治疗分配进行盲法，但采取了多项措施来降低评估偏倚的风险，包括围绕标准操作程序、共同定义和评估重复进行教育。该 5 年研究的预计完成日期为 2011 年 12 月。
