title: Evaluation of coagulation studies from heparinized arterial lines with use of Lab-Site high-pressure tubing.
abstract: Heparinized arterial catheters are commonly used in critically ill patients to monitor pressures and to collect blood for laboratory analysis. To remove the heparinized fluid used to keep these lines patent large volumes of blood are often withdrawn and discarded or calculations of tube volume must be made. Repeated violation of stopcocks may lead to contamination and infection of arterial lines. In addition, discarded blood has become an increasing concern as a source of infection for health care personnel. This study evaluates the efficacy of noncompliant arterial line tubing that contains two polymer sampling ports permanently placed at prefixed distances such that if blood is withdrawn to the distal port, undiluted arterial blood can then be withdrawn from the proximal port. Blood from arterial lines that consisted of 20-gauge catheters connected to Lab-Site tubing was withdrawn in the method suggested by the manufacturer with no removal or wasting of excess blood from the system. Prothrombin time (PT) and activated partial thromboplastin time (aPTT) studies performed on this sample were compared with those performed on a simultaneously drawn venous sample. Regression analysis showed a correlation coefficient of 0.966 for PT and 0.935 for aPTT, demonstrating an excellent correlation for the technique. The average arterial PT was 0.12 seconds less than venous control and the average arterial aPTT was 0.49 seconds greater than control. Neither of these differences was significant. We conclude that this type of high-pressure tubing allows accurate blood samples to be obtained from arterial lines without the necessity of precise calculations or blood wastage.
authors.affiliation: University of Tennessee College of Medicine, Memphis.
authors.forename: R S
authors.initials: RS
authors.lastname: Cicala
authors.forename: K
authors.initials: K
authors.lastname: Cannon
authors.forename: J S
authors.initials: JS
authors.lastname: Larson
authors.forename: T C
authors.initials: TC
authors.lastname: Fabian
mesh_terms: D001780:Blood Coagulation Tests; D001800:Blood Specimen Collection; D002405:Catheterization, Central Venous; D002408:Catheters, Indwelling; D006439:Hemodynamics; D006493:Heparin; D006801:Humans; D010314:Partial Thromboplastin Time; D011312:Pressure; D011517:Prothrombin Time
chemical_list: D006493:Heparin