Tampere University Heart Hospital Tampere, Tampere, Finland.
Tampere University Hospital, Tampere, Finland.
Acta Anaesthesiol Scand. 2022 Oct;66(9):1083-1090. doi: 10.1111/aas.14122. Epub 2022 Aug 12.
Low-molecular-weight heparin enoxaparin is widely used in pharmacological thromboprophylaxis after coronary artery bypass grafting (CABG). The aim of this study was to compare anti-factor X activity (anti-Xa) levels when the thromboprophylactic dose of enoxaparin was provided after CABG, with two different administration routes: continuous intravenous infusion (CIV) and subcutaneous bolus (SCB) injection. We hypothesized that the current standard method of SCB administration might lead to lower anti-Xa levels than recommended in other patient groups, due to reduced bioavailability.
In this prospective, randomized, controlled clinical trial, 40 patients scheduled for elective CABG were randomized to receive 40 mg of enoxaparin per day either as CIV or SCB for 72 h. Enoxaparin was initiated 6-10 h after CABG. Anti-Xa levels were measured 12-14 times during the study period. The primary outcome, that is, the maximum anti-Xa concentration over 0-24 h (C ), was calculated from these measured values. Secondary outcomes were C and the trough concentration of anti-Xa after 72 h of enoxaparin initiation (C ).
Twenty patients were randomized to the CIV-group and 19 to the SCB-group. The median anti-Xa C was significantly lower in the CIV-group than in the SCB-group: 0.15 [interquartile range (IQR) 0.13-0.19] IU/ml versus 0.25 (IQR 0.18-0.32) IU/ml, p < .005. The median anti-Xa C was 0.12 (IQR, 0.1-0.17) IU/ml versus 0.23 (IQR 0.19-0.31) IU/ml, respectively, p < .005. At 72 h, there was no difference between the groups in their anti-Xa levels.
In this low-risk CABG patient population, SCB administration of a thromboprophylactic dose of enoxaparin provided anti-Xa levels that are considered sufficient for thromboprophylaxis in other patient groups. CIV administration resulted in lower anti-Xa levels compared to the SCB route.
低分子肝素依诺肝素广泛用于冠状动脉旁路移植术（CABG）后的药理学血栓预防。本研究旨在比较在 CABG 后给予预防性依诺肝素时，两种不同给药途径（持续静脉输注（CIV）和皮下推注（SCB）注射）的抗因子 X 活性（anti-Xa）水平。我们假设由于生物利用度降低，目前 SCB 给药的标准方法可能导致抗 Xa 水平低于其他患者群体的推荐水平。
在这项前瞻性、随机、对照临床试验中，40 名择期 CABG 患者被随机分为连续静脉输注（CIV）或皮下推注（SCB）注射，每天接受 40mg 依诺肝素，持续 72 小时。依诺肝素在 CABG 后 6-10 小时开始使用。在研究期间测量了 12-14 次抗 Xa 水平。从这些测量值中计算主要结果，即 0-24 小时的最大抗 Xa 浓度（C ）。次要结果是依诺肝素起始后 72 小时的 C 和抗 Xa 谷浓度（C ）。
20 名患者被随机分配到 CIV 组，19 名患者被分配到 SCB 组。CIV 组的中位抗 Xa C 明显低于 SCB 组：0.15（四分位距[IQR]0.13-0.19）IU/ml 与 0.25（IQR 0.18-0.32）IU/ml，p<0.005。C 中位抗 Xa C 分别为 0.12（IQR，0.1-0.17）IU/ml 与 0.23（IQR，0.19-0.31）IU/ml，p<0.005。在 72 小时时，两组的抗 Xa 水平没有差异。
在这个低风险的 CABG 患者人群中，SCB 给予预防性依诺肝素的剂量可提供被认为足以预防其他患者群体血栓形成的抗 Xa 水平。与 SCB 途径相比，CIV 给药导致较低的抗 Xa 水平。
