DOACDipstick从患者的尿液样本和手工制作的试纸以及商业版本中明确确定是否存在直接口服抗凝剂(DOAC)。比较肝素治疗患者的血浆样品的血浆活性(显色底物测定)与尿液样品(DOAC试纸)的结果,低分子量肝素(LMWH)和不抗凝。通过Coamatic显色底物测定法测定血浆抗因子Xa(aXa)活性,并通过DOAC测试条与尿液中抗凝剂的存在进行比较。患者治疗至少5天,并在给药后4小时采集样品,与没有用抗凝剂治疗相比(n=42)。共有100例患者接受肝素治疗(n=29),LMWH纳曲肝素(n=29)或无抗凝剂(n=42)。肝素治疗患者的血浆aXa水平(每天皮下2×7.500IU,12男,年龄67.4±11.5岁)为0.18IU/ml±0.15IU/ml(平均值,标准偏差),使用LMWH(每天皮下1×3000IU,15男,年龄64.2±14.1岁)0,17IU/ml±0,16IU/l,并且没有抗凝剂(28名男性,年龄64.2±15.6岁)0.02IU/ml±0.01IU/ml。测试条的所有因子Xa和凝血酶抑制剂垫结果均为阴性。我们得出的结论是,DOACDipstick在接受治疗的患者以及未接受抗凝剂治疗的患者的尿液样本中检测不到肝素和LMWH的可能性很高。
DOAC Dipstick determines specifically the presence and absence of direct oral anticoagulants (DOACs) from patients\' urine samples and handmade test strips performed as well as the commercial version. To compare plasma activity (chromogenic substrate assays) from plasma samples with results from urine samples (DOAC test strips) of patients treated with heparin, low-molecular weight heparin (LMWH) and without anticoagulation. Plasma anti-factor Xa (aXa) activity was determined by Coamatic chromogenic substrate assay and compared to the presence of anticoagulants in urine by DOAC test strips. Patients were treated for least 5 days and samples were taken 4 hrs after administration in comparison to no treatment with an anticoagulant (n = 42). A total of 100 patients were included treated with heparin (n = 29), LMWH nadroparin (n = 29) or no anticoagulants (n = 42). Plasma aXa levels of patients treated with heparin (2 × 7.500 IU daily subcutaneously, 12 male, age 67.4 ± 11.5 years) were 0,18 IU/ml ± 0,15 IU/ml (mean, standard deviation), with LMWH (1 × 3000 IU daily subcutaneously, 15 male, age 64.2 ± 14.1 years) 0,17 IU/ml ± 0,16 IU/l, and with no anticoagulants (28 male, age 64.2 ± 15.6 years) 0,02 IU/ml ± 0.01 IU/ml. All factor Xa and thrombin inhibitor pad results of test strips were negative. We conclude that DOAC Dipstick has a high probability of not detecting heparin and LMWH in patients on treatment as well as in urine samples of patients not treated with an anticoagulant.