Atchison Christie, Widdershins Afton, Chandler Wayne L
Department of Critical Care, Seattle Children's Hospital, Seattle, Washington, USA.
Department of Laboratories, Seattle Children's Hospital, Seattle, Washington, USA.
Artif Organs. 2023 Jan;47(1):160-167. doi: 10.1111/aor.14395. Epub 2022 Oct 5.
Most pediatric patients show a decline in platelet counts while on extracorporeal life support (ECLS) and require multiple platelet transfusions. To better understand platelet loss during ECLS, this study estimated platelet loss rates due to diagnostic phlebotomy, platelet activation, bleeding and other causes.
We collected data on 91 patients (1d-20y, 50 M, 41F). Platelet losses were estimated based on changes in platelet count, patient+circuit blood volume, and transfused platelet volumes. Platelet extracellular vesicles were measured by flow cytometry.
Median platelet loss was 2.8 × 10 /L/hr, more than twice the normal rate of platelet removal and equivalent to a 67 000/μl decrease in platelet count per day. While platelet loss was correlated with platelet transfusion (r = 0.51), transfusion underestimated platelet loss in patients with large decreases in platelet count and over-estimated platelet loss in neonates where the circuit volume > patient blood volume. Patients with disseminated intravascular coagulation before or significant bleeding during ECLS have double the rate of platelet loss. Platelet activation accounted for ~32% of total platelet loss, bleeding ~36% and phlebotomy 4%, with the remaining one-third due to other causes. Annexin-negative platelet extracellular vesicle release, a measure of platelet damage, was increased 9-fold during ECLS.
Our study is the first to quantitate total, phlebotomy and activation related platelet loss during ECLS. Platelet activation accounts for ~32% of total platelet loss, while bleeding doubles the platelet loss rate. The etiology of the remaining platelet loss is unknown.
大多数儿科患者在接受体外生命支持（ECLS）时血小板计数会下降，需要多次输注血小板。为了更好地了解ECLS期间的血小板损失情况，本研究估计了诊断性静脉穿刺、血小板激活、出血及其他原因导致的血小板损失率。
我们收集了91例患者（年龄1天至20岁，男性50例，女性41例）的数据。根据血小板计数、患者加体外循环血量及输注血小板量的变化来估计血小板损失。通过流式细胞术检测血小板细胞外囊泡。
血小板损失中位数为2.8×10⁹/L/小时，是正常血小板清除率的两倍多，相当于血小板计数每天减少67000/μl。虽然血小板损失与血小板输注相关（r = 0.51），但在血小板计数大幅下降的患者中，输注量低估了血小板损失，而在体外循环血量大于患者血量的新生儿中，输注量高估了血小板损失。在ECLS前发生弥散性血管内凝血或期间有大量出血的患者，血小板损失率加倍。血小板激活约占总血小板损失的32%，出血约占36%，静脉穿刺占4%，其余三分之一归因于其他原因。膜联蛋白阴性的血小板细胞外囊泡释放（一种血小板损伤的指标）在ECLS期间增加了9倍。
我们的研究首次对ECLS期间总的、与静脉穿刺及激活相关的血小板损失进行了定量。血小板激活约占总血小板损失的32%，而出血使血小板损失率加倍。其余血小板损失的病因尚不清楚。
