Department of Anesthesia and Intensive Care Medicine, University of Basel Hospital, Basel, Switzerland.
Platelets. 2009 Nov;20(7):458-65. doi: 10.3109/09537100903236462.
Point-of-care platelet monitoring is increasingly used in cardiac patients treated with antiplatelet agents. The validity of a new assay needs to be evaluated not only for reproducible data in clinical samples, but also for other pre-analytical conditions that may influence measurements. The aim of this study was to evaluate the influence of a pneumatic tube system (PTS) for specimen transport on impedance platelet aggregometry. We evaluated 50 consecutive patients scheduled for coronary artery bypass surgery under oral therapy with 100 mg/d acetylsalicylic acid (aspirin). In each patient, three blood samples for platelet function analysis were taken before induction of anesthesia. The first sample was measured in the operating room (OR) area and designated as the reference value. The second sample was again measured by the same operator in the OR area using a random PTS transport. The third sample was sent to the central laboratory by PTS where it was measured by a local technician. Platelet function was assessed in whole blood by impedance aggregometry with a Multiplate analyzer using thrombin-related activation peptide (TRAP test) and arachidonic acid (ASPI test) (Dynabite GmbH, Munich, Germany). Mean +/- SD for TRAP test was 1009 +/- 196 in the reference measurement. Bias +/- 95% limit of agreement between the reference measurement and a second measurement for TRAP test were 126 +/- 284 (n = 25) for untransported and 181 +/- 316 (n = 25) for PTS transported samples. In the reference measurements, 48/50 (96%) of TRAP values were within the normal range. After PTS transport, 35/50 (70%) of TRAP measurements in the central laboratory were within the normal range (p < 0.001). Mean +/- SD for ASPI test was 175 +/- 137. Bias +/- 95% limit of agreement for ASPI test were 12 +/- 109 (n = 25) for untransported and 68 +/- 250 (n = 25) for PTS transported samples. In the reference measurements, 7/50 (14%) ASPI values were above the cut-off level and defined as reduced aspirin responsiveness. After PTS transport, only 1/50 (2%) of the patients showed reduced aspirin responsiveness in the central laboratory measurements (p = 0.031). In conclusion, PTS transport had a significant influence on platelet function testing by the Multiplate() analyzer. Significantly fewer test results indicated normal platelet function in TRAP test and reduced aspirin responsiveness in ASPI test after PTS transport. Therefore, clinical decisions regarding platelet function and aspirin responsiveness should not be based on blood specimens transported by a PTS system.
即时血小板监测在接受抗血小板药物治疗的心脏病患者中越来越多地使用。新检测方法的有效性不仅需要在临床样本中评估可重复的数据，还需要评估可能影响测量的其他分析前条件。本研究旨在评估气动输送管系统（PTS）对阻抗血小板聚集检测的影响。我们评估了 50 例连续接受口服 100mg/d 乙酰水杨酸（阿司匹林）治疗的拟行冠状动脉旁路手术的患者。在每个患者中，在麻醉诱导前采集 3 份血小板功能分析样本。第一份样本在手术室（OR）区域进行测量，指定为参考值。第二份样本由同一位操作员在 OR 区域再次使用随机 PTS 输送进行测量。第三份样本由 PTS 送到中央实验室，由当地技术员进行测量。采用血栓素相关激活肽（TRAP 试验）和花生四烯酸（ASPI 试验）的阻抗聚集仪（Multiplate 分析仪）在全血中评估血小板功能（ Dynabite GmbH，慕尼黑，德国）。TRAP 试验的参考测量值的平均值 +/-SD 为 1009 +/- 196。TRAP 试验参考测量值与 PTS 输送样本的第二次测量值之间的偏倚 +/-95%一致性界限为 126 +/- 284（n = 25）和 181 +/- 316（n = 25）。在参考测量值中，50 份 TRAP 值中有 48/50（96%）在正常范围内。经 PTS 输送后，中央实验室中 50 份 TRAP 测量值中有 35/50（70%）在正常范围内（p < 0.001）。ASPI 试验的平均值 +/-SD 为 175 +/- 137。ASPI 试验的偏倚 +/-95%一致性界限为 12 +/- 109（n = 25）和 68 +/- 250（n = 25）对于未输送和 PTS 输送的样本。在参考测量值中，7/50（14%）的 ASPI 值高于截止值，定义为阿司匹林反应性降低。经 PTS 输送后，只有 1/50（2%）的患者在中央实验室测量中表现出阿司匹林反应性降低（p = 0.031）。总之，PTS 输送对 Multiplate()分析仪的血小板功能检测有显著影响。经 PTS 输送后，TRAP 试验中表示正常血小板功能的检测结果和 ASPI 试验中表示阿司匹林反应性降低的检测结果明显减少。因此，关于血小板功能和阿司匹林反应性的临床决策不应基于 PTS 系统输送的血液样本。
