title: Hirudin monitoring using the TAS ecarin clotting time in patients with heparin-induced thrombocytopenia type II.
abstract: OBJECTIVE
  To assess the reliability of the TAS/ecarin clotting time (ECT) for on-line monitoring of r-hirudin in cardiovascular surgery with and without cardiopulmonary bypass (CPB).
  
  
  METHODS
  Samples were spiked with r-hirudin (0 to 5 microg/mL) and calibration curves constructed. Reproducibility was evaluated by measurement of the sample five times at each concentration. The influence of variations in hematocrit, plasma factors, and platelet count on the test results was examined. Samples were obtained from patients during cardiovascular surgery with CPB (n = 8), without CPB (n = 3), and from volunteers (n = 5) and compared with the laboratory reference tests. All tests were performed in duplicate.
  
  
  METHODS
  Deutsches Herzzentrum Berlin.
  
  
  METHODS
  Five healthy volunteers and 11 patients undergoing cardiovascular surgery.
  
  
  METHODS
  None.
  
  
  RESULTS
  The TAS/ECT showed linearity and reliability to an r-hirudin concentration of 5 microg/mL and was not influenced (p < 0.005) by the varying conditions of the in vitro setup. The correlation to the laboratory method was 0.74 for the CPB group and 0.87 for the non-CPB group.
  
  
  CONCLUSIONS
  The TAS/ECT is a reliable assay for monitoring r-hirudin at the point of care. With this information, the use of r-hirudin during surgery or angioplasty should become more effective and safer.
authors.affiliation: Department of Anaesthesiology, Deutsches Herzzentrum, Charité, Berlin, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Koster
authors.forename: R
authors.initials: R
authors.lastname: Hansen
authors.forename: O
authors.initials: O
authors.lastname: Grauhan
authors.forename: H
authors.initials: H
authors.lastname: Hausmann
authors.forename: M
authors.initials: M
authors.lastname: Bauer
authors.forename: R
authors.initials: R
authors.lastname: Hetzer
authors.forename: H
authors.initials: H
authors.lastname: Kuppe
authors.forename: F
authors.initials: F
authors.lastname: Mertzlufft
mesh_terms: D000328:Adult; D000368:Aged; D000925:Anticoagulants / Q000097:blood*; D002315:Cardiopulmonary Bypass; D016903:Drug Monitoring; D005260:Female; D006493:Heparin / Q000009:adverse effects*; D006629:Hirudins / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011994:Recombinant Proteins / Q000097:blood; D015203:Reproducibility of Results; D013921:Thrombocytopenia / Q000139:chemically induced*; D014914:Whole Blood Coagulation Time
chemical_list: D000925:Anticoagulants; D006629:Hirudins; D011994:Recombinant Proteins; D006493:Heparin