Mayo D J, Dimond E P, Kramer W, Horne M K
Critical Care, Heart, Lung, Blood, and Cancer Nursing Service, Warren Grant Magnuson Clinical Center, National Institutes of Health, Bethesda, MD, USA.
Oncol Nurs Forum. 1996 May;23(4):671-5.
PURPOSE/OBJECTIVES: Determine the blood volume that must be wasted to obtain a clinically useful prothrombin time (PT), activated partial thromboplastin time (APTT), and fibrinogen concentration for blood drawn from a heparinized (2.5 ml of 100 units/ml), double-lumen venous catheter.
Prospective, nonrandomized study comparing test results obtained from blood samples drawn through the catheters with those obtained via peripheral venipuncture. Patients acted as their own control.
Inpatient and outpatient units of a cancer research center located in a mid-Atlantic city in the United States.
Twenty double-lumen 10 Fr. Hickman catheters (Bard Access Systems, Salt Lake City, UT) were studied in 20 adult patients with cancer who had no history of coagulation disorders.
Samples were collected from the red lumen of 20 heparinized, double-lumen Hickman catheters after 5, 10, 15, 20, and 25 ml of blood first were discarded. PTs, APTTs, and fibrinogen concentrations were measured on each sample. The results were compared with those derived from a simultaneously obtained peripheral blood sample.
PT, APTT, and fibrinogen values of blood samples after 5, 10, 15, 20, and 25 ml discards and PT, APTT, and fibrinogen of peripheral blood samples.
The coagulation results using peripheral blood were always within the normal range except for one slightly elevated APTT. After 25 ml of discard, all of the PTs and fibrinogen concentrations and 95% of the APTTs of catheter blood were within the normal range and therefore clinically useful.
Clinically useful PTs, APTTs, and fibrinogen concentrations often can be derived with catheter-drawn blood when the objective is to confirm normal coagulation. However, because it is very difficult to obtain heparin-free samples through heparinized, double-lumen Hickman catheters, peripheral blood should be drawn for coagulation testing when a totally heparin-free sample is needed to make a critical clinical decision.
These findings provide important information for practice when nurses have to decide whether to draw coagulation tests through a heparinized catheter. Further research is needed with larger samples in varied populations (e.g., pediatrics) to study catheters made of different materials and of different calibers.
目的/目标：确定从肝素化（2.5毫升100单位/毫升）双腔静脉导管抽取血液时，为获得临床上有用的凝血酶原时间（PT）、活化部分凝血活酶时间（APTT）和纤维蛋白原浓度必须废弃的血量。
前瞻性、非随机研究，比较通过导管抽取的血样与外周静脉穿刺获取的血样的检测结果。患者自身作为对照。
位于美国大西洋中部一座城市的癌症研究中心的住院部和门诊部。
对20名无凝血障碍病史的成年癌症患者的20根10 Fr双腔希克曼导管（巴德接入系统公司，犹他州盐湖城）进行研究。
在首先丢弃5、10、15、20和25毫升血液后，从20根肝素化双腔希克曼导管的红色管腔采集样本。对每个样本测量PT、APTT和纤维蛋白原浓度。将结果与同时采集的外周血样本的结果进行比较。
丢弃5、10、15、20和25毫升血液后血样的PT、APTT和纤维蛋白原值以及外周血样本的PT、APTT和纤维蛋白原。
除一例APTT略有升高外，外周血的凝血结果始终在正常范围内。丢弃25毫升血液后，导管血的所有PT和纤维蛋白原浓度以及95%的APTT在正常范围内，因此在临床上可用。
当目的是确认凝血正常时，通过导管抽取的血液通常可以得出临床上有用的PT、APTT和纤维蛋白原浓度。然而，由于通过肝素化双腔希克曼导管很难获得无肝素样本，当需要完全无肝素样本以做出关键临床决策时，应抽取外周血进行凝血检测。
这些发现为护士必须决定是否通过肝素化导管进行凝血检测时的实践提供了重要信息。需要在不同人群（如儿科）中用更大样本进一步研究由不同材料和不同管径制成的导管。
