PB1035 - Monitoring of unfractionated heparin in critical ill ICU patients: a prospective study comparing aPTT and point-of-care viscoelastic testing with IN / HI ratio to anti-Xa

Tuesday, June 27, 2023

18:30 – 19:30 ET

Room: Exhibition

Presenting Author(s)

Lars Heubner, MD

Anesthesiology Resident / post-doc Research Fellow
University Hospital “Carl Gustav Carus”, Technische Universität Dresden, Department of Anesthesiology and Intensive Care Medicine, Dresden, Saxony, Germany
Dresden, Sachsen, Germany

Co-Author(s)

AD

Anna Dietze

Doctoral Student
University Hospital “Carl Gustav Carus”, Technische Universität Dresden, Department of Anesthesiology and Intensive Care Medicine, Dresden, Saxony, Germany
Dresden, Sachsen, Germany
OT

Oliver Tiebel

Associate director
University Hospital “Carl Gustav Carus”, Technische Universität Dresden, Institute of Clinical Chemistry, Dresden, Saxony, Germany
Dresden, Sachsen, Germany
AG

Andreas Güldner

Senior physician
University Hospital “Carl Gustav Carus”, Technische Universität Dresden, Department of Anesthesiology and Intensive Care Medicine, Dresden, Saxony, Germany
Dresden, Sachsen, Germany
OV

Oliver Vicent

Senior physician
University Hospital “Carl Gustav Carus”, Technische Universität Dresden, Department of Anesthesiology and Intensive Care Medicine, Dresden, Saxony, Germany
Dresden, Sachsen, Germany
Jan Beyer-Westendorf, MD,PhD

Head of Division "Thrombosis and Hemostasis", Head of „Thrombosis Research“
University Hospital “Carl Gustav Carus”, Technische Universität Dresden, Division of Hematology and Hemostasis, Department of Medicine I Thrombosis Research, Dresden, Saxony, Germany
Dresden, Sachsen, Germany
TK

Thea Koch

Head of department
University Hospital “Carl Gustav Carus”, Technische Universität Dresden, Department of Anesthesiology and Intensive Care Medicine, Dresden, Saxony, Germany
Dresden, Sachsen, Germany
PS

Peter Spieth

Deputy director
University Hospital “Carl Gustav Carus”, Technische Universität Dresden, Department of Anesthesiology and Intensive Care Medicine, Dresden, Saxony, Germany
Dresden, Sachsen, Germany

Background: Anticoagulation is indicated for the prevention or therapy of thromboembolic events, but remains highly challenging considering the high risk of bleeding events in critically ill patients. Unfractionated heparin (UFH) is widely used as preferred anticoagulation for patients on intensive care units (ICU). For monitoring of UFH, activated partial thromboplastin time (aPTT) is mainly used, but using specific UFH calibrated anti-Xa levels is an established alternative to overcome aPTT limitations. Using point-of-care (POC) viscoelastic testing (VET) with a specific ratio between clotting time (CT) in intrinsic test (IN-test) compared to heparinase test (HI-test) might be an alternative.

Aims: The aim of this was to compare aPTT and POC VET with IN/HI ratio to clinical relevant anti-Xa target levels.

Methods: From 09/2020 to 07/2022, 467 samples from 120 adult ICU patients receiving UFH therapy were prospectively collected. Samples for aPTT, anti-Xa measurement and CT using ClotPro® (Haemonetics, Boston, Massachusetts, USA) were simultaneously collected. Measurement for aPTT (C.K. Prest) and anti-Xa (Liquid AntiXa) were performed using STA R Max 3 device (Stago Deutschland GmbH, Düsseldorf). This study was approved by the local Ethics Committee at the Technische Universität Dresden, Germany (BO-EK- 374072021).

Results: Table 1 presents anti-Xa target levels for UFH and median results for aPTT and CT IN/HI ratio according to our institutional guidelines. CT IN/HI ratio correlation to anti-Xa levels was considerably better than aPTT correlation (Figures 1). Notably, aPTT could not exactly discriminate between patients receiving UFH dosages correlating to high-risk prophylaxis or therapeutic anticoagulation.

Conclusion(s): Whole blood POC VET using a specific heparinase-approach (IN/HI ratio) is superior to aPTT in detecting patients in or out of targeted anti-Xa levels. POC VET should be made available for ICUs as bedside test and might help to guide anticoagulation management in critical ill patients, being faster and potentially more widely available than lab-based anti-Xa testing.