title: Monitoring of unfractionated heparin with rotational thrombelastometry using the prothrombinase-induced clotting time reagent (PiCT®).
abstract: OBJECTIVE
  To achieve sufficient and safe anticoagulation with unfractionated heparin (UFH) a close and reliable drug monitoring is necessary. In general, the activated partial thromboplastin time (APTT) is used for this purpose. In acute phase response, however, the APTT test procedure might be unreliable e.g. with false low results in the presence of elevated factor VIII. In this so called heparin resistance, measurement of anti-Xa activity is recommended over APTT to avoid potentially harmful dose escalation. A combination of anti-Xa measurement and global hemostatic testing with ROTEM® employing the anti-Xa sensitive PiCT® reagent showed high correlation with enoxaparin levels. This test modification could also be suitable for monitoring UFH. Aim of the study was to evaluate the correlation between PiCT®-ROTEM® and levels of UFH.
  
  
  METHODS
  In this in-vitro study blood samples from healthy volunteers were spiked with UFH and subjected to different ROTEM® tests.
  
  
  RESULTS
  There was a linear correlation between UFH level and clotting time (CT) in the PiCT®-ROTEM® test with an excellent correlation coefficient of 0.92. Additional endpoints showed similar results (PiCT®-ROTEM® MaxVel r = -0.85 and PiCT®-ROTEM® t_MaxVel r = 0.88).
  
  
  CONCLUSIONS
  As a point-of-care applicable tool ROTEM® is immediately at hand. If further clinical studies confirm sensitivity in heparin resistance, PiCT®-ROTEM® could permit rapid UFH dose adjustments especially required in critical illness with acute phase response.
authors.affiliation: Dept of Anesthesiology, General Intensive Care and Pain Control, Medical University of Vienna, Vienna, Austria. eva.schaden@meduniwien.ac.at
authors.forename: E
authors.initials: E
authors.lastname: Schaden
authors.forename: S
authors.initials: S
authors.lastname: Jilch
authors.forename: S
authors.initials: S
authors.lastname: Hacker
authors.forename: A
authors.initials: A
authors.lastname: Schober
authors.forename: S
authors.initials: S
authors.lastname: Kozek-Langenecker
mesh_terms: D000328:Adult; D001780:Blood Coagulation Tests; D005260:Female; D006493:Heparin / Q000097:blood*; D006801:Humans; D008297:Male; D012016:Reference Values; D012399:Rotation; D012680:Sensitivity and Specificity; D013916:Thrombelastography; D013925:Thromboplastin / Q000378:metabolism*
chemical_list: D006493:Heparin; D013925:Thromboplastin