This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (2) Citing Articles via Google Scholar Google Scholar Articles by Hansen, R. Articles by Kuppe, H. Search for Related Content PubMed PubMed Citation Articles by Hansen, R. Articles by Kuppe, H.

---

CARDIOVASCULAR ANESTHESIA

A Quick Anti-Xa-Activity-Based Whole Blood Coagulation Assay for Monitoring Unfractionated Heparin During Cardiopulmonary Bypass: A Pilot Investigation

Roland Hansen, MD^*, Andreas Koster, MD, Marian Kukucka, MD, Fritz Mertzlufft, MD, PhD, and Herrmann Kuppe, MD, PhD

*Institute for Laboratory Medicine and Pathobiochemistry, Campus Virchow Klinikum, Charité, Berlin; Institute for Anesthesiology, Deutsches Herzzentrum Berlin, Berlin; and Clinics for Anesthesiology and Intensive Care Medicine, University Clinics of the Saarland, Homburg Saar, Germany

Address correspondence and reprint requests to Andreas Koster, MD, Deutsches Herzzentrum Berlin, Augustenburgerplatz 1, 13353 Berlin, Germany. Address e-mail to Koster{at}DHZB.de

We developed a quick and easy method to perform anti-Xa-activity-based whole blood assay and assessed its reliability for online monitoring of unfractionated heparins (UFHs) during cardiopulmonary bypass. Seventy-five microliters of a mixture of 1:3 large- and small-range Heptest®^TM reagent were transferred into blank cartridges of the ACT II device. The plastic flags for clot detection and stirring the sample and reagent were inserted and overlaid with 75 µL of Recalmix for recalcification. One-hundred fifty microliters of citrated whole blood were added and measurements performed. In vitro, the linearity of the test over a range of 1–8 IU/mL UFH, as well as the influence of variations in hematocrit (60%, 30%, and 20%), plasma coagulation factors (50%, 30%, and 20%) and platelets (100, 50, and 20 x 10³/µL) on the test results were assessed. In vivo measurements performed during cardiopulmonary bypass were compared with the chromogenic assay. The test revealed linearity to concentrations of 6 IU/mL of UFH and was not significantly influenced by the variations in the in vitro set-up despite a prolongation in samples with a hematocrit of 60%. In vivo, the correlation to the chromogenic test was R = 0.90. The ACT II anti-Xa-UFH assay performed in whole blood was reliable when used over a wide range of conditions that could be encountered clinically. Although the test is useful for point-of-care monitoring, the necessity of individual calibrations and pipetting in the operation room requires further automation before its use in clinical practice.

Implications: The ACT II anti-Xa-unfractionated heparin assay allows for reliable monitoring of large concentrations of UFH over a wide range of hematocrit, platelet, and coagulation factor levels. Further evaluation of this point-of-care device is indicated.

This article has been cited by other articles:

				W. C. Oliver Jr Overview of Heparin and Protamine Management and Dosing Regimens in Pediatric Cardiac Surgical Patients Seminars in Cardiothoracic and Vascular Anesthesia, December 1, 2003; 7(4): 387 - 410. [Abstract] [PDF]

				A. Koster, G. Despotis, M. Gruendel, T. Fischer, M. Praus, H. Kuppe, and J. H. Levy The Plasma Supplemented Modified Activated Clotting Time for Monitoring of Heparinization During Cardiopulmonary Bypass: A Pilot Investigation Anesth. Analg., July 1, 2002; 95(1): 26 - 30. [Abstract] [Full Text] [PDF]