Evaluation of Residual Anti-Xa Activity As A Function Of Time Following The Last Treatment Dose of Enoxaparin In Patients Presenting For Elective Surgery
试验速览
- 阶段
- 4 期
- 状态
- 终止
- 入组人数
- 122
- 试验地点
- 1
- 主要终点
- Time Point at Which Anti-Xa Activity is Lower Than 0.2 International Unit Per Milliliter (IU/mL) Using Modeling
研究概览
简要总结
The main objective of this study is to determine the time interval following the last treatment dose of enoxaparin at which the amount of anti-Xa level activity is reliably less than 0.2 international unit per milliliter (IU/mL) in patients presenting for elective surgery.
详细描述
Enoxaparin is a factor Xa inhibitor commonly used for both prophylaxis against and treatment of thromboembolism. It is also frequently used off-label as a perioperative bridge for patients that are chronically anticoagulated prior to surgery, such as those taking Warfarin. It is an attractive option for perioperative use secondary to its predictable pharmacologic profile and the lack of recommended routine blood monitoring. Therefore, it is common to encounter a patient who has recently received a treatment dose of Enoxaparin prior to presenting for surgery. For these patients, and those on other anticoagulant medications, published guidelines have been developed to help guide clinical decision-making when the anesthetic/analgesic plan includes regional anesthesia.1 Currently, these guidelines recommend that a minimum of 24-hours should elapse following the last treatment dose of Enoxaparin before a neuraxial procedure is performed. However, a recently completed quality improvement project conducted at Wake Forest Baptist Medical Center found that almost 60% of patients presenting for surgery while on treatment dose enoxaparin still had significant anticoagulant activity 24-hours following their last dose, as demonstrated by anti-Xa level assay testing. Given that the risk of epidural hematoma formation is increased in the setting of abnormal coagulation parameters, the significance of this finding is that the risk of bleeding complications following a neuraxial procedure may still be increased 24-hours after the last treatment dose of enoxaparin.
While the routine use of anti-Xa level testing may be a viable option to determine when residual enoxaparin activity is present before proceeding with a neuraxial procedure on a patient-by-patient basis, it is not universally available at all hospitals. Therefore, it is important to determine the time interval following the last enoxaparin dose at which the likelihood that a clinically relevant amount of residual anti-Xa level activity no longer persists, so that providers can confidently proceed with a neuraxial procedure when anti-Xa level testing is not available.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Basic Science
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 100 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Eligible patients need:
- •to be on treatment dose (1mg/kg twice daily or 1.5mg/kg daily) enoxaparin at the time of presentation for elective surgery
- •and must be able to accurately report the timing of their last dose and the administered dosage.
- •Patients must also be between the ages of 18-100 years of age
- •and must be able to give written consent to participate.
排除标准
- •Patients with severe renal insufficiency (creatinine clearance <30ml/min) will be excluded from the study, as the elimination of enoxaparin is known to be affected in this patient population.
- •Pregnant patients will also be excluded, as the elimination and metabolism of enoxaparin is known to be altered in this patient population, and dose adjustments are recommended if treatment dose enoxaparin is used during pregnancy.
- •Patients who are receiving enoxaparin as a bridge from another anti-Xa inhibiting medication will be excluded as this could unpredictably affect the results of anti-Xa testing. These medications include: Apixaban, Edoxaban, Fondaparinux, and Xarelto.
研究组 & 干预措施
24 Hours group
Group one will be instructed to administer their last dose of enoxaparin at 07:00 in the morning on the day prior to their scheduled surgery date. This will mean that patients who have their surgery scheduled for 07:00 the following day will be 24-hours removed from their last dose. Patients presenting for surgery later in the day would be slightly farther removed from their last dose, however this is currently considered normal clinical practice.
干预措施: Enoxaparin (Drug)
36 Hours Group
Group 2 will be instructed to administer their last dose of enoxaparin at 19:00 in the evening two days prior to their scheduled surgery date. Patients presenting for surgery at 07:00 two days later will be 36-hours removed from their last dose. Patients presenting for surgery later in the day would be slightly farther removed from their last dose, but again this mimics normal clinical practice in which the timing of the last dose of self-administered enoxaparin is not routinely adjusted based on the scheduled surgical start time.
干预措施: Enoxaparin (Drug)
结局指标
主要结局
Time Point at Which Anti-Xa Activity is Lower Than 0.2 International Unit Per Milliliter (IU/mL) Using Modeling
时间窗: Time Frame: 24 hours or 36 hours (based on randomization) after the last treatment dose of enoxaparin. Actual lab draw will vary, as planned, given surgical arrival time.
The randomization of patients to either the 24-hour group or the 36-hour group will allow for modeling, which will generate a prediction of the time point at which the level of anti-Xa activity can reliably be assumed to be lower than 0.2 IU/mL.
Residual Anti-Xa Activity Levels Following Last Treatment Dose of Enoxaparin
时间窗: Time Frame: 24 hours or 36 hours (based on randomization) after the last treatment dose of enoxaparin. Actual lab draw will vary, as planned, given surgical arrival time.
Anti-Xa level activity will be measured in both groups using a chromogenic assay and a hybrid curve calibrated to both heparin and enoxaparin.
次要结局
- Relationship Between Anti-Xa Levels and Patient Age(Anti-Xa levels were measured at the time of presentation for surgery. Age was collected at the time of enrollment.)
- Relationship Between Anti-Xa Levels and Patients Gender (Sex)(Anti-Xa levels were measured at the time of presentation for surgery. Gender was collected at the time of enrollment.)