Department of Surgery, Johannesburg Hospital, University of Witwatersrand, Johannesburg, South Africa.
Transfusion. 2009 Dec;49 Suppl 5:240S-7S. doi: 10.1111/j.1537-2995.2008.01987.x.
The secret with any alternative to transfusion is to minimize the need for transfusion in the first place. This can be done by reducing the volume of blood loss. The volume of blood being lost can be reduced by direct methods where possible (i.e., hemostasis at the point of bleeding), or by improving the coagulation profile of the patient, thereby improving the extrinsic coagulation. Recombinant activated factor VII (rFVIIa) offers theoretical possibilities of improving the coagulation profile.
The efficacy and safety of rFVIIa for the treatment of bleeding in patients with severe blunt and penetrating trauma has been investigated in two double-blind, placebo-controlled studies within a single trial-one on patients with blunt injury and the other in similar patients with penetrating injury.
In patients with blunt trauma alive at 48 hours, treatment with rFVIIa effected a significant reduction in the primary endpoint of 48-hour red blood cell (RBC) transfusion requirement (p = 0.02), and the safety of the dosing regimen was established. Similar trends were observed in patients with penetrating injuries. Across both studies and treatment arms, the 48-hour mortality rate ranged from 16 to 19 percent. In the blunt trauma study, this equated to 13 patients from each arm who died before the benefits of treatment could be adequately assessed. Analysis of data for the 117 blunt trauma patients who survived at least 48 hours after receiving study treatment shows that, in addition to reducing RBC requirement, rFVIIa significantly reduced the need for massive transfusion over 48 hours (>20 RBC units) (relative risk reduction of 56% [95% confidence interval: 9%-79%]; p = 0.03), and the fresh-frozen plasma (p = 0.036), platelet (p = 0.023), and cryoprecipitate (p = 0.053) requirements within 48 hours, and was associated with a significant reduction in the 30-day risk of acute respiratory distress syndrome (ARDS) (p = 0.05) and multiple organ failure and/or ARDS (p = 0.05).
Treatment with adjunctive rFVIIa significantly reduces transfusion requirements in the 48 hours after severe injury and these procoagulant effects may improve clinical outcome at 30 days.
替代输血的关键是首先尽量减少输血的需求。这可以通过减少失血量来实现。如果可能的话,可以通过直接方法(即止血在出血点)减少失血的量,或者通过改善患者的凝血状态,从而改善外源性凝血。重组活化因子 VII(rFVIIa)提供了改善凝血状态的理论可能性。
在一项单一试验中,对严重钝性和穿透性创伤患者的出血进行了两项双盲、安慰剂对照研究,以评估 rFVIIa 的疗效和安全性-一项针对钝性损伤患者,另一项针对类似的穿透性损伤患者。
在 48 小时存活的钝性创伤患者中,rFVIIa 治疗显著降低了 48 小时红细胞(RBC)输注需求的主要终点(p=0.02),并且确定了剂量方案的安全性。在穿透性损伤患者中也观察到类似的趋势。在两项研究和治疗组中,48 小时死亡率范围为 16%至 19%。在钝性创伤研究中,这相当于每个手臂各有 13 名患者在治疗的益处能够得到充分评估之前死亡。对接受研究治疗至少 48 小时后存活的 117 名钝性创伤患者的数据进行分析表明,除了减少 RBC 需求外,rFVIIa 还显著减少了 48 小时内大量输血的需求(>20 RBC 单位)(相对风险降低 56%[95%置信区间:9%-79%];p=0.03),并减少了 48 小时内新鲜冷冻血浆(p=0.036)、血小板(p=0.023)和冷沉淀(p=0.053)的需求,并且与 30 天急性呼吸窘迫综合征(ARDS)(p=0.05)和多器官衰竭和/或 ARDS(p=0.05)的风险降低显著相关。
辅助使用 rFVIIa 可显著减少严重损伤后 48 小时内的输血需求,这些促凝作用可能会改善 30 天的临床结果。