Division of Trauma and Surgical Critical Care, Daughtry Family Department of Surgery, University of Miami School of Medicine, Ryder Trauma Center, Miami, Florida 33136, USA.
J Trauma Acute Care Surg. 2012 Aug;73(2):385-90. doi: 10.1097/TA.0b013e31825a0519.
Central venous catheters (CVCs) increase the risk of venous thromboembolism. We have previously demonstrated that pulmonary artery catheters are associated with a hypercoagulable state in an animal model and in patients. The purpose of this study is to determine whether the insertion of a CVC is associated with a similar response.
7F femoral artery catheters were placed in healthy anesthetized swine (N = 16). Serial arterial blood samples were drawn immediately before and after an 8.5F jugular vein CVC and then for 3 hours after CVC removal. Samples were analyzed using kaolin-activated thromboelastography (TEG) at precisely 2 minutes. Human: An institutional review board-approved prospective observational trial was conducted, with informed consent, in patients with critical illness (N = 8) at a Level I trauma center. Blood was drawn from indwelling arterial catheters immediately before and 60 minutes after CVC insertion. Samples were stored in sodium citrate for 15 minutes before TEG. Routine and special coagulation tests were performed on stored samples in the hospital pathology laboratory.
Insertion of a CVC decreased TEG clotting time (R) by 55% in swine and by 29% in humans (p < 0.001 and 0.019, respectively). Initial clot formation time (K) was reduced by 41% in swine and by 36% in humans (p = 0.003 and 0.019). Fibrin cross-linking (α) was accelerated by 28% in swine and by 17% in humans (p = 0.007 and 0.896), but overall clot strength (maximum amplitude) was not affected. There was no change in routine or special coagulation factors, including von Willebrand factor, antithrombin III, prothrombin time, international normalized ratio, or activated partial thromboplastin time. In animals, the hypercoagulable TEG response was persistent for 3 hours after CVC removal and was prevented by pretreatment with enoxaparin (n = 4) but not heparin (n = 2).
In healthy swine and patients with critical illness, a systemic hypercoagulable state occurred after CVC insertion, and this may partially account for an increased risk of venous thromboembolism. However, because the sample size was small and not powered to detect changes in coagulation proteins, no inferences can be made about the mechanism for the hypercoagulable response.
中心静脉导管（CVC）会增加静脉血栓栓塞的风险。我们之前已经证明，肺动脉导管在动物模型和患者中与高凝状态有关。本研究的目的是确定 CVC 的插入是否与类似的反应有关。
将 7F 股动脉导管放置在健康麻醉的猪中（N=16）。在插入 8.5F 颈静脉 CVC 之前和之后立即抽取连续的动脉血样本，然后在 CVC 取出后 3 小时内抽取样本。使用高岭土激活的血栓弹性图（TEG）在 2 分钟时精确分析样品。
在一级创伤中心的危重病患者（N=8）中进行了机构审查委员会批准的前瞻性观察性试验，并获得了知情同意。从留置的动脉导管中立即抽取血液，并在 CVC 插入后 60 分钟抽取血液。将样品储存在柠檬酸钠中 15 分钟，然后进行 TEG。在医院病理实验室中对储存的样品进行常规和特殊凝血测试。
在猪中，CVC 的插入使 TEG 凝血时间（R）降低了 55%，在人类中降低了 29%（p<0.001 和 0.019，分别）。初始凝血形成时间（K）在猪中降低了 41%，在人类中降低了 36%（p=0.003 和 0.019）。纤维蛋白交联（α）在猪中加速了 28%，在人类中加速了 17%（p=0.007 和 0.896），但整体血凝块强度（最大振幅）没有受到影响。常规或特殊凝血因子（包括血管性血友病因子、抗凝血酶 III、凝血酶原时间、国际标准化比值或活化部分凝血活酶时间）均无变化。在动物中，CVC 去除后 3 小时内仍存在高凝 TEG 反应，并用依诺肝素（n=4）预处理可预防，但肝素（n=2）不行。
在健康的猪和危重病患者中，CVC 插入后会发生全身性高凝状态，这可能部分解释了静脉血栓栓塞风险增加的原因。然而，由于样本量较小且没有能力检测凝血蛋白的变化，因此不能对高凝反应的机制做出任何推断。
