Transfusion Center and Haematology Laboratory, Legnano Hospital, ASST Ovest Milanese, Legnano, Italy.
Intensive Care Unit, Legnano Hospital, ASST Ovest Milanese, Legnano, Italy.
Int J Lab Hematol. 2021 Dec;43(6):1284-1290. doi: 10.1111/ijlh.13543. Epub 2021 Apr 14.
Patients with COVID-19 frequently exhibit a hypercoagulable state with high thrombotic risk, particularly those admitted to intensive care units (ICU). Thromboprophylaxis is mandatory in these patients; nevertheless, thrombosis still occurs in many cases. Thus, the problem of assessing an adequate level of anticoagulation in ICU patients becomes evident during the COVID-19 pandemic. The aim of this study was to evaluate the heparin resistance and the efficacy of heparin monitoring using an anti-Xa activity assay.
Thirty-seven heparin-treated patients admitted to ICU for SARS-CoV-2 pneumonia were retrospectively studied for antifactor Xa activity (anti-Xa), activated partial thromboplastin time (APTT), Antithrombin, Fibrinogen, D-Dimer, Factor VIII, von Willebrand Factor, and the total daily amount of heparin administered. The correlation between APTT and anti-Xa was evaluated for unfractionated heparins (UFH). The correlations between the daily dose of UFH or the dosage expressed as IU/kg b.w. for low molecular weight heparin (LMWH) and anti-Xa were also evaluated.
Twenty-one patients received calcium heparin, 8 sodium heparin, and 8 LMWH. A moderate correlation was found between APTT and anti-Xa for UFH. APTT did not correlate with coagulation parameters. 62% of UFH and 75% of LMWH treated patients were under the therapeutic range. About 75% of patients could be considered resistant to heparin.
SARS-COV2 pneumonia patients in ICU have frequently heparin resistance. Anti-Xa seems a more reliable method to monitor heparin treatment than APTT in acute patients, also because the assay is insensitive to the increased levels of fibrinogen, FVIII, and LAC that are common during the COVID-19 inflammatory state.
COVID-19 患者常表现出高血栓风险的高凝状态，尤其是那些住进重症监护病房（ICU）的患者。这些患者必须进行血栓预防；然而，许多情况下仍会发生血栓。因此，在 COVID-19 大流行期间，评估 ICU 患者的抗凝水平是否足够成为一个明显的问题。本研究旨在评估肝素抵抗和使用抗 Xa 活性测定法监测肝素的效果。
回顾性研究了 37 例因 SARS-CoV-2 肺炎住进 ICU 接受肝素治疗的患者，检测了抗因子 Xa 活性（抗 Xa）、活化部分凝血活酶时间（APTT）、抗凝血酶、纤维蛋白原、D-二聚体、VIII 因子、血管性血友病因子和每天给予的肝素总剂量。评估了未分级肝素（UFH）的 APTT 与抗 Xa 的相关性。还评估了 UFH 的每日剂量或 LMWH 以 IU/kg b.w. 表示的剂量与抗 Xa 的相关性。
21 例患者接受了钙肝素，8 例患者接受了钠肝素，8 例患者接受了低分子肝素（LMWH）。UFH 中发现 APTT 与抗 Xa 之间存在中度相关性。APTT 与凝血参数不相关。62%的 UFH 和 75%的 LMWH 治疗患者未处于治疗范围内。约 75%的患者可能对肝素产生抵抗。
住进 ICU 的 SARS-COV2 肺炎患者经常出现肝素抵抗。与 APTT 相比，抗 Xa 似乎是监测肝素治疗的更可靠方法，因为该检测法对 COVID-19 炎症状态下常见的纤维蛋白原、VIII 因子和 LAC 水平升高不敏感。
