Platelet damage caused by the centrifugal pump: in vitro evaluation by measuring the release of alpha-granule packing proteins.
Platelet damage caused by the centrifugal pump: in vitro evaluation by measuring the release of alpha-granule packing proteins.
复制标题
离心泵引起的血小板损伤：通过测量α颗粒包装蛋白的释放进行体外评估。
作者：
K. Kawahito;J. Mohara;Y. Misawa;K. Fuse
血小板比红细胞更容易受损，因为血小板在与体外循环回路接触以及受到剪切力作用时很容易被激活。然而，离心泵对血小板造成损伤的程度尚不清楚。为了评估不同泵血条件下的血小板损伤情况，在体外模拟左心室辅助装置（LVAD）和体外循环（CPB）条件下，测量了血小板α - 颗粒中特定蛋白质、β - 血小板球蛋白（β - TG）和血小板第4因子（PF - 4）的增加速率，并与红细胞损伤情况进行了比较。研究了LVAD在流量为5.0 L/min、压力差（ΔP）为100 mmHg（低压头条件）以及CPB在流量为5.0 L/min、压力差为350 mmHg（高压头条件）时的情况。使用新鲜人血，在带有Capiox（泰尔茂，东京，日本）离心泵的模拟回路中，每种条件进行4次、每次3小时的测试。每隔1小时采集血液样本，测量血浆游离血红蛋白（fHb）、β - TG和PF - 4。为了评估损伤程度，针对每种条件计算fHb、β - TG和PF - 4的增加速率，分别为ΔfHb/ΔN、Δβ - TG/ΔN和ΔPF - 4/ΔN，其中ΔfHb是血浆游离血红蛋白的增加量，Δβ - TG是β - TG的增加量，ΔPF - 4是PF - 4的增加量，ΔN是通过次数的增加量。通过次数由以下公式定义：N = Qt/V，其中t是时间，V是预充量，Q是流量。两种条件（低压头条件与高压头条件）下fHb的增加速率之间没有显著差异（0.0035 ± 0.0004对0.0034 ± 0.0010 g/100 L，无显著差异）。与此相反，高压头条件下血小板α - 颗粒中特定蛋白质的增加速率明显高于低压头条件。低压头条件下β - TG的平均增加速率为0.22 ± 0.03 ng/ml，高压头条件下为0.51 ± 0.05 ng/ml（p < 0.05）。低压头条件下PF - 4的增加速率为0.11 ± 0.02 ng/ml，高压头条件下为0.30 ± 0.06 ng/ml（p < 0.05）。这些结果表明，对于评估血细胞损伤，β - TG和PF - 4的测量可能是比溶血更敏感的参数，并且血小板比红细胞更容易受到离心泵的机械损伤。
Platelets are more vulnerable to damage than erythrocytes because platelets are easily activated by contact with extracorporeal circuits and by exposure to shear forces. However, the degree of platelet damage caused by centrifugal pumps is unclear. To evaluate platelet damage in different pumping conditions, the rates of increase for specific proteins in platelet alpha-granules, beta-thromboglobulin (beta-TG), and platelet factor 4 (PF-4) were measured in both in vitro simulated left ventricular assist device (LVAD) and cardiopulmonary bypass (CPB) conditions and compared with the erythrocyte trauma. A flow of 5.0 L/min with deltaP of 100 mm Hg for LVAD (low pressure head condition) and a flow of 5.0 L/min with deltaP of 350 mm Hg for CPB (high pressure head condition) were investigated. Each condition was tested 4 times for 3 h in a mock circuit with a Capiox (Terumo, Tokyo, Japan) centrifugal pump using fresh human blood. Blood was sampled at 1 h intervals, measuring plasma free hemoglobin (fHb), beta-TG, and PF-4. To evaluate the degree of damage, the rates of increase of fHb, beta-TG, and PF-4 were calculated for each condition as deltafHb/deltaN, deltabeta-TG/deltaN, and deltaPF-4/deltaN where deltafHb is the increase in plasma free hemoglobin, deltabeta-TG is the increase in beta-TG, deltaPF-4 is the increase in PF-4, and deltaN is the increase in the passing number. The passing number is defined in the following equation: N = Qt/V where t is the time, V is the priming volume, and Q is the flow rate. There was no significant difference between the 2 conditions (low pressure head condition versus high pressure head condition) in the rate of increase of fHb (0.0035+/-0.0004 vs. 0.0034+/-0.0010 g/100 L, NS). Contrary to this, the rates of increase for specific proteins in platelet alpha-granules in the high pressure head condition demonstrated a significantly higher rate of increase than in the low pressure head condition. The mean rate of increase for beta-TG in the low pressure head condition was 0.22+/-0.03 ng/ml and in the high pressure head condition was 0.51+/-0.05 ng/ml (p < 0.05). The rate of increase for PF-4 in the low pressure head condition was 0.11+/-0.02 ng/ml and in the high pressure head condition was 0.30+/-0.06 ng/ml (p < 0.05). These results suggest that measurements of beta-TG and PF-4 may be more sensitive parameters than hemolysis for evaluating blood cell trauma and that platelets are more vulnerable to mechanical damage by a centrifugal pump than erythrocytes.