Lawson M
J Intraven Nurs. 1991 May-Jun;14(3):157-9.
Partial occlusion of indwelling central venous catheters (CVCs) developed as a clinical problem following the trend to leave CVCs in place for the duration of intravenous therapy, which can last for more than 1 year in some cases. The primary manifestation of partial catheter occlusion is the ability to infuse but not aspirate fluids through an indwelling CVC. There is evidence that the problem is at least partially related to a residue of blood products deposited within some CVCs and implanted ports each time blood is aspirated or infused. Over time, these deposits may act as a ball valve when aspiration from the CVC is attempted while still allowing fluid or drug infusions. A preliminary investigation has indicated that this partial occlusion can be corrected by the use of a fibrinolytic drug to "cleanse" the CVC of residual blood products through lysis, thus restoring full CVC patency. Controlled studies are still needed to determine how often the CVC should be cleansed to prevent buildup of blood products in the indwelling CVC.
随着在静脉治疗期间留置中心静脉导管（CVC）的趋势出现，部分留置CVC闭塞成为了一个临床问题，在某些情况下，静脉治疗可能持续超过1年。部分导管闭塞的主要表现是能够通过留置CVC输注液体，但无法回抽液体。有证据表明，该问题至少部分与每次回抽或输注血液时沉积在一些CVC和植入端口内的血液制品残余物有关。随着时间的推移，当试图从CVC回抽时，这些沉积物可能会起到球阀的作用，同时仍允许液体或药物输注。一项初步调查表明，通过使用纤溶药物通过溶解作用“清除”CVC内的残余血液制品，可纠正这种部分闭塞，从而恢复CVC的完全通畅。仍需进行对照研究来确定应多久清洗一次CVC，以防止留置CVC内血液制品的积聚。
