Khoschnewis Schahla, Hannes Françoise Marie, Tschopp Markus, Wuillemin Walter A
Division of Hematology and Central Hematology Laboratory, Kantonsspital Laboratory, Kantonsspital Luzern, 6000 Lucerne 16, Switzerland.
Thromb Res. 2004;113(5):327-32. doi: 10.1016/j.thromres.2004.03.021.
The prothrombin time (PT), also called thromboplastin time ("Quick"), is usually measured using citrated plasma from venous blood. Recently, portable coagulation monitors have been developed, which measure PT using non-anticoagulant capillary whole blood from a finger stick. In the present study, we compared the International Normalized Ratio (INR) of the standard laboratory method (INRven) with the newly developed reagent PT(N) for the CoaguChek Pro portable monitor (INRcap) in various patient groups: healthy individuals, patients with oral anticoagulation and patients with a deficiency of coagulation factor V, factor VII or factor X, respectively.
One hundred and fifty-five patients were included in this prospective open comparison study. Capillary PT was measured with the portable coagulation monitor CoaguChek Pro using the new disposable cartridge PT(N) (containing rabbit brain thromboplastin). In comparison, PT was measured using citrated venous plasma and the reagent Innovin on the coagulation analyzer STA-R.
We found a correlation coefficient of 0.85 between capillary and venous INR values among the 100 patients with oral anticoagulation. The slope of the regression line was 1.4 and the y-intercept is -0.65. Agreement between both methods was found to be 80% (95% CI: 72-88%) and the standard-agreement was 85% (95% CI: 78-92%). Among the 30 healthy subjects, the individual differences between INRven and INRcap were in 4 cases 0, in 21 cases 0.1 and in 5 cases 0.2.
The new test cartridge PT(N) was found to be a valuable tool for measuring PT among healthy subjects. However, among patients with oral anticoagulation, agreement between INRcap measured with the new cartridge PT(N) and INRven was only moderate. Our results show that improvements are necessary for a more valuable measurement of capillary PT with portable coagulation monitors.
凝血酶原时间（PT），也称为凝血活酶时间（“Quick”），通常使用静脉血的枸橼酸盐血浆进行测量。最近，已开发出便携式凝血监测仪，其使用来自手指针刺的非抗凝毛细血管全血来测量PT。在本研究中，我们比较了标准实验室方法（INRven）的国际标准化比值（INR）与新开发的用于CoaguChek Pro便携式监测仪的试剂PT（N）（INRcap）在不同患者组中的情况：健康个体、口服抗凝剂的患者以及分别缺乏凝血因子V、因子VII或因子X的患者。
155名患者纳入了这项前瞻性开放比较研究。使用便携式凝血监测仪CoaguChek Pro和新的一次性检测盒PT（N）（含兔脑凝血活酶）测量毛细血管PT。相比之下，使用枸橼酸盐静脉血浆和凝血分析仪STA - R上的试剂Innovin测量PT。
在100名口服抗凝剂的患者中，我们发现毛细血管和静脉INR值之间的相关系数为0.85。回归线的斜率为1.4，y轴截距为 - 0.65。两种方法之间的一致性为80%（95%CI：72 - 88%），标准一致性为85%（95%CI：78 - 92%）。在30名健康受试者中，INRven和INRcap之间的个体差异在4例中为0，在21例中为0.1，在5例中为0.2。
新的检测盒PT（N）被发现是在健康受试者中测量PT的有价值工具。然而，在口服抗凝剂的患者中，使用新检测盒PT（N）测量的INRcap和INRven之间的一致性仅为中等。我们的结果表明，对于使用便携式凝血监测仪更有价值地测量毛细血管PT而言，有必要进行改进。
