From the Departments of Pharmacy Services and Pharmacy Practice (M.E.D., E.W.M., C.A.D., N.E.E., S.P.K., D.M.L.), Department of Nursing (K.M.B., J.A.L., E.A.K.), and Division of Trauma and Critical Care (K.P.A., D.J.H., B.R.H.R.), Department of Surgery, University of Cincinnati Medical Center, Cincinnati, Ohio.
J Trauma Acute Care Surg. 2014 Feb;76(2):450-6. doi: 10.1097/TA.0000000000000087.
Low anti-factor Xa (anti-Xa) concentrations with twice-daily enoxaparin are associated with venous thromboembolism (VTE) in high-risk trauma patients. Concerns have been raised with once-daily dalteparin regarding effectiveness and achievable anti-Xa concentrations. The purpose of this before-and-after study was to evaluate the effectiveness of a VTE prophylaxis protocol using anti-Xa concentrations and associated dalteparin dose adjustment in high-risk trauma patients.
Adult trauma patients receiving VTE chemoprophylaxis and hospitalized for at least 3 days were prospectively followed during two 6-month epochs before (PRE) and after (POST) implementation of anti-Xa monitoring. In both groups, high-risk patients received dalteparin 5,000 U subcutaneously once daily; low-risk patients received subcutaneous unfractionated heparin. High-risk POST patients with anti-Xa less than 0.1 IU/mL 12 hours after initial dalteparin dose received dalteparin every 12 hours. All patients underwent routine VTE ultrasound surveillance of the lower extremities. The primary outcome was incidence of VTE.
A total of 785 patients (PRE, n = 428; POST, n = 357) were included. Demographics, injury patterns, Injury Severity Score (ISS), red blood cell transfusions, intensive care unit and hospital stays, and mortality did not differ between groups. Overall, POST patients had lower VTE (7.0% vs. 13%, p = 0.009) including acute VTE (6.4% vs. 12%, p = 0.01) and proximal deep vein thromboembolism (2.2% vs. 5.7%, p = 0.019). Between high-risk patients, VTE occurred in 53 (16.3%) PRE compared with 24 (9.0%) POST patients (p = 0.01); there was no difference in VTE between low-risk patients (PRE, 2.0% vs. POST, 1.1%; p = 0.86). Among 190 high-risk POST patients with anti-Xa, 97 (51%) were less than 0.1 IU/mL. Patients with low anti-Xa had higher rates of VTE (14.0% vs. 5.4%, p = 0.05) and deep vein thromboembolism (14.4% vs. 3.2%, p = 0.01). Younger age (odds ratio, 0.97; 95% confidence interval, 0.95-0.99) and greater weight (odds ratio, 1.02; 95% confidence interval, 1.00-1.03) predicted low anti-Xa on multivariate regression.
A VTE prophylaxis protocol using anti-Xa-based dalteparin dosage adjustment in high-risk trauma patients was associated with decreased VTE. Once-daily dalteparin 12-hour anti-Xa concentrations are suboptimal in a majority of patients and associated with VTE.
Therapeutic study, level IV.
高危创伤患者每日两次使用依诺肝素时，抗因子 Xa（anti-Xa）浓度较低与静脉血栓栓塞症（VTE）有关。每日一次达肝素在有效性和可达到的抗 Xa 浓度方面存在顾虑。本前后对照研究旨在评估使用抗 Xa 浓度和相关达肝素剂量调整的 VTE 预防方案在高危创伤患者中的效果。
前瞻性随访接受 VTE 化学预防并至少住院 3 天的成年创伤患者，在实施抗 Xa 监测前后（PRE 和 POST）进行两个 6 个月的时间区间。在两组中，高危患者均接受达肝素 5000U 皮下注射，每日一次；低危患者接受未分级肝素皮下注射。在初始达肝素剂量后 12 小时，抗 Xa 小于 0.1IU/mL 的高危 POST 患者每 12 小时接受一次达肝素。所有患者均接受下肢常规 VTE 超声监测。主要结局为 VTE 的发生率。
共纳入 785 例患者（PRE，n=428；POST，n=357）。两组患者的人口统计学、损伤模式、损伤严重程度评分（ISS）、红细胞输注、重症监护病房和住院时间以及死亡率无差异。总体而言，POST 患者的 VTE 发生率较低（7.0% vs. 13%，p=0.009），包括急性 VTE（6.4% vs. 12%，p=0.01）和近端深静脉血栓形成（2.2% vs. 5.7%，p=0.019）。在高危患者中，PRE 组有 53 例（16.3%）发生 VTE，而 POST 组有 24 例（9.0%）（p=0.01）；低危患者的 VTE 发生率无差异（PRE，2.0% vs. POST，1.1%；p=0.86）。在 190 例接受 POST 治疗的高危患者中，有 97 例（51%）抗 Xa 小于 0.1IU/mL。抗 Xa 水平较低的患者 VTE 发生率（14.0% vs. 5.4%，p=0.05）和深静脉血栓形成发生率（14.4% vs. 3.2%，p=0.01）较高。年龄较小（比值比，0.97；95%置信区间，0.95-0.99）和体重较大（比值比，1.02；95%置信区间，1.00-1.03）是多变量回归分析中抗 Xa 水平较低的预测因素。
高危创伤患者使用基于抗 Xa 的达肝素剂量调整的 VTE 预防方案与 VTE 减少相关。每日一次达肝素的 12 小时抗 Xa 浓度在大多数患者中不理想，且与 VTE 相关。
治疗性研究，IV 级。
