Department of Anaesthesia and Critical Care, Royal Papworth Hospital, Cambridge Biomedical Campus, Cambridge, UK.
Division of Clinical Haematology and Blood Transfusion, Cambridge University Hospitals, Cambridge, UK.
Clin Appl Thromb Hemost. 2022 Jan-Dec;28:10760296221148162. doi: 10.1177/10760296221148162.
Support with VV-ECMO requires anticoagulation with unfractionated heparin to prevent thrombotic complications. This must be monitored due to bleeding risk. A point-of-care (POC) method of testing aPTT and APR was evaluated for agreement with laboratory methods. In a prospective observational study, patients supported on VV-ECMO as a result of severe respiratory failure secondary to Covid-19 infection were given heparin as part of standard therapy. The aPTT was measured (i) at the bedside using the Hemochron Signature Elite device and (ii) at the hospital laboratory. Duplicate results were compared. Agreement between the POC and laboratory tests was poor, as assessed using the Bland-Altman method. The maximum difference between POC and laboratory methods was 133% and the minimum was 0%. Overall bias was 7.3% and limits of agreement were between -43.8% and 58.5%. Correlation increased when results were normalised to platelet count and creatinine. This POC test is insufficiently accurate for use as the primary method of heparin monitoring in patients requiring VV-ECMO for Covid-19. Platelets and renal function may influence the result of this whole blood POC test.
VV-ECMO 支持需要使用未分馏肝素进行抗凝以预防血栓并发症。由于存在出血风险，因此必须进行监测。评估了一种即时检测（POC）检测 aPTT 和 APR 的方法，以评估其与实验室方法的一致性。在一项前瞻性观察研究中，因 COVID-19 感染导致严重呼吸衰竭而接受 VV-ECMO 支持的患者接受肝素作为标准治疗的一部分。使用 Hemochron Signature Elite 设备在床边测量（i）aPTT 和在医院实验室测量（ii）aPTT。比较重复结果。使用 Bland-Altman 方法评估，POC 和实验室测试之间的一致性较差。POC 和实验室方法之间的最大差异为 133%，最小差异为 0%。总体偏差为 7.3%，一致性界限在-43.8%和 58.5%之间。当将结果归一化为血小板计数和肌酐时，相关性增加。对于因 COVID-19 需要 VV-ECMO 的患者，这种即时检测作为肝素监测的主要方法不够准确。血小板和肾功能可能会影响这种全血 POC 测试的结果。
