Puget Sound Blood Center, Seattle, WA 98104-1256, USA.
N Engl J Med. 2010 Feb 18;362(7):600-13. doi: 10.1056/NEJMoa0904084.
We conducted a trial of prophylactic platelet transfusions to evaluate the effect of platelet dose on bleeding in patients with hypoproliferative thrombocytopenia.
We randomly assigned hospitalized patients undergoing hematopoietic stem-cell transplantation or chemotherapy for hematologic cancers or solid tumors to receive prophylactic platelet transfusions at a low dose, a medium dose, or a high dose (1.1x10(11), 2.2x10(11), or 4.4x10(11) platelets per square meter of body-surface area, respectively), when morning platelet counts were 10,000 per cubic millimeter or lower. Clinical signs of bleeding were assessed daily. The primary end point was bleeding of grade 2 or higher (as defined on the basis of World Health Organization criteria).
In the 1272 patients who received at least one platelet transfusion, the primary end point was observed in 71%, 69%, and 70% of the patients in the low-dose group, the medium-dose group, and the high-dose group, respectively (differences were not significant). The incidences of higher grades of bleeding, and other adverse events, were similar among the three groups. The median number of platelets transfused was significantly lower in the low-dose group (9.25x10(11)) than in the medium-dose group (11.25x10(11)) or the high-dose group (19.63x10(11)) (P=0.002 for low vs. medium, P<0.001 for high vs. low and high vs. medium), but the median number of platelet transfusions given was significantly higher in the low-dose group (five, vs. three in the medium-dose and three in the high-dose group; P<0.001 for low vs. medium and low vs. high). Bleeding occurred on 25% of the study days on which morning platelet counts were 5000 per cubic millimeter or lower, as compared with 17% of study days on which platelet counts were 6000 to 80,000 per cubic millimeter (P<0.001).
Low doses of platelets administered as a prophylactic transfusion led to a decreased number of platelets transfused per patient but an increased number of transfusions given. At doses between 1.1x10(11) and 4.4x10(11) platelets per square meter, the number of platelets in the prophylactic transfusion had no effect on the incidence of bleeding. (ClinicalTrials.gov number, NCT00128713.)
我们进行了一项预防性血小板输注的试验，以评估血小板剂量对低增生性血小板减少症患者出血的影响。
我们将接受造血干细胞移植或血液系统恶性肿瘤或实体瘤化疗的住院患者随机分为低剂量、中剂量或高剂量组（分别为每平方米体表面积输注 1.1x10(11)、2.2x10(11)或 4.4x10(11)个血小板），当清晨血小板计数低至 10,000/立方毫米或更低时。每天评估临床出血迹象。主要终点是根据世界卫生组织标准定义的 2 级或更高等级的出血。
在接受至少一次血小板输注的 1272 名患者中，低剂量组、中剂量组和高剂量组分别有 71%、69%和 70%的患者出现主要终点（差异无统计学意义）。三组之间更高等级出血和其他不良事件的发生率相似。低剂量组输注的血小板中位数（9.25x10(11)）明显低于中剂量组（11.25x10(11)）或高剂量组（19.63x10(11)）（低 vs. 中剂量，P=0.002；低 vs. 高剂量和高 vs. 中剂量，P<0.001），但低剂量组输注的血小板中位数（5 次，中剂量组和高剂量组均为 3 次；低 vs. 中剂量和低 vs. 高剂量，P<0.001）显著更高。与血小板计数为 6000 至 80,000/立方毫米的研究日相比，血小板计数为 5000/立方毫米或更低的研究日有 25%发生出血（P<0.001）。
低剂量血小板预防性输注可减少每位患者输注的血小板数量，但增加了输注次数。在每平方米 1.1x10(11)至 4.4x10(11)个血小板的剂量范围内，预防性输注的血小板数量对出血发生率没有影响。（临床试验.gov 编号，NCT00128713）。
