Use of thrombin inhibitors ex vivo allows critical care clinical chemistry and hematology testing on common specimens

• Published in: Clinical biochemistry 1997-03, Vol.30 (2), p.121-127
• Main Authors: Lyon, Andrew W., Harding, Sheila Rutledge, Drobot, Duane, Lyon, Martha E.
• Format: Article
• Language: English
• Subjects: Amino Acid Chloromethyl Ketones; anticoagulants; Antithrombins; Argatroban; Blood Chemical Analysis; Blood Preservation - methods; Blood Specimen Collection - methods; Critical Care - methods; Humans; lithium heparin; Pipecolic Acids; pre-analytical error; thrombin inhibitors
• ISSN: 0009-9120; 1873-2933
• DOI: 10.1016/S0009-9120(96)00158-0

Objective: To evaluate the suitability of the thrombin inhibitors PPACK (D-phenylalanyl-L-prolyl-L-arginine chloromethylketone) or Argatroban for anticoagulation of blood prior to critical care testing of whole blood or plasma. Design and Methods: Initially we evaluated the effect of PPACK (0–200 μM) or Argatroban (0–590 μM) on serum glucose, urea, creatinine, calcium and electrolyte tests on two chemistry analyzers (Hitachi 717 and Ektachem 700XR). Subsequently plasma and serum from whole blood samples containing either heparin 15,000 IU/L or PPACK 75 μM or Argatroban 245 μM or no anticoagulant were tested and compared. We analysed and compared whole blood containing either PPACK 75 μM or Argatroban 245 μM or ethylenediaminetetraacetic acid (EDTA) using a Coulter STK-R® hematology analyzer at intervals for 90 minutes. Results: The measurement of electrolytes, urea, creatinine, calcium or glucose was unaffected by either Argatroban or PPACK in either serum or anticoagulant-specific plasmas ( p > 0.05). For specimens from individual donors, serum potassium was higher than plasma potassium, irrespective of anticoagulant used. Clinically equivalent complete blood counts were achieved for 60 minutes using EDTA-whole blood, or whole blood containing 245 μM Argatroban or 75 μM PPACK. However automated differential white cell counting was not reliable with either form of thrombin inhibitor-whole blood. Argatroban-anticoagulated blood demonstrated concentration and time dependent changes in platelet counts, whereas platelet counts were stable in blood containing 75 μM PPACK for up to 90 minutes. Conclusion: Specimens of blood anticoagulated with either 75 μM PPACK or 245 μM Argatroban can be used for either critical care chemistry or hematology testing.