Geriatric Unit A, Azienda Ospedaliera Universitaria Integrata, Verona, Italy.
Laboratory of Clinical Chemistry and Hematology, Azienda Ospedaliera Universitaria Integrata, Verona, Italy.
Aging Clin Exp Res. 2018 Jun;30(6):605-608. doi: 10.1007/s40520-017-0822-8. Epub 2017 Aug 14.
The aim of this study was to evaluate the activity of anti-activated factor X (anti-Xa) in patients with different degrees of chronic renal failure (CRF), treated with therapeutic doses of low molecular weight heparin.
This prospective study evaluated the effect of age, renal function, BMI, gender, in determining the efficacy and safety of treatment with enoxaparin, evaluated by assessing the anti-Xa. The therapeutic anticoagulant range was set between 0.20 and 0.70 U/mL.
Two hospital geriatric units.
98 patients (64 men, 34 women, mean age 82 years) with CRF, treated with enoxaparin at therapeutic dosage, for deep vein thrombosis or acute coronary syndrome.
Anti-Xa was assessed 4 h after the third administration of LMWH using Chromogenix test. Renal function was assessed by calculating creatinine clearance according to Cockcroft formula.
The dose of enoxaparin ranged between 53 and 200 U/kg; total 4000-16000 U/day. The mean anti-Xa was 0.41 U/mL (95% CI 0.36-0.45). Multiple regression analysis selected only the dose of enoxaparin, but not age, creatinine clearance, BMI, gender, as a predictor of anti-Xa serum levels. In seven patients anti-Xa was above the range but none of them received more than 150 U/Kg enoxaparin (100 U/kg if creatinine clearance <30 mL/min). Ten patients (eight men, two women) showed suboptimal levels of anti-Xa, regardless enoxaparin dose or creatinine clearance.
Enoxaparin dose reduction according to renal function decreases the risk of overdosing and potentially the risk of bleeding. The risk of under dosing seems less predictable; therefore, anti-Xa assay may be useful in severe clinical situations that require higher anticoagulant activity.
本研究旨在评估不同程度慢性肾衰竭（CRF）患者接受治疗剂量低分子肝素治疗时抗活化因子 X（anti-Xa）的活性。
这项前瞻性研究评估了年龄、肾功能、BMI、性别对依诺肝素治疗效果和安全性的影响，通过评估 anti-Xa 来评估。治疗性抗凝范围设定在 0.20 至 0.70 U/mL 之间。
两个医院老年病房。
98 例（64 名男性，34 名女性，平均年龄 82 岁）CRF 患者，接受依诺肝素治疗剂量，用于治疗深静脉血栓或急性冠脉综合征。
在第三次使用 LMWH 后 4 小时使用 Chromogenix 法检测 anti-Xa。根据 Cockcroft 公式计算肌酐清除率来评估肾功能。
依诺肝素剂量范围为 53 至 200 U/kg；每天总剂量为 4000 至 16000 U。平均 anti-Xa 为 0.41 U/mL（95%CI 0.36-0.45）。多元回归分析仅选择依诺肝素剂量，而非年龄、肌酐清除率、BMI、性别，作为 anti-Xa 血清水平的预测因子。在 7 名患者中，anti-Xa 水平高于范围，但没有一名患者接受超过 150 U/kg 依诺肝素（如果肌酐清除率<30 mL/min，则为 100 U/kg）。10 名患者（8 名男性，2 名女性）无论依诺肝素剂量或肌酐清除率如何，anti-Xa 水平均不理想。
根据肾功能减少依诺肝素剂量可降低药物过量的风险，潜在出血风险也降低。药物剂量不足的风险似乎更难预测；因此，在需要更高抗凝活性的严重临床情况下，anti-Xa 检测可能有用。
