Blood viscosity during coagulation at different shear rates

Authors

  • Marco Ranucci,

    1. Department of Cardiothoracic, Vascular Anesthesia and Intensive Care, IRCCS Policlinico San Donato, Milan, Italy
    Search for more papers by this author
  • Tommaso Laddomada,

    1. Department of Cardiothoracic, Vascular Anesthesia and Intensive Care, IRCCS Policlinico San Donato, Milan, Italy
    Search for more papers by this author
  • Matteo Ranucci,

    Corresponding author
    1. Department of Cardiothoracic, Vascular Anesthesia and Intensive Care, IRCCS Policlinico San Donato, Milan, Italy
    • Correspondence

      Marco Ranucci, Director of Clinical Research in the Department of Anesthesia and Intensive Care, IRCCS Policlinico San Donato, Via Morandi 30, 20097 San Donato Milanese, Milan, Italy.

      Tel: +39-02-52774320

      Fax: +39-02-55602262

      E-mail: cardioanestesia@virgilio.it

    Search for more papers by this author
  • Ekaterina Baryshnikova

    1. Department of Cardiothoracic, Vascular Anesthesia and Intensive Care, IRCCS Policlinico San Donato, Milan, Italy
    Search for more papers by this author

  • Funding Information

    This study has been funded by local research funds of the IRCCS Policlinico San Donato.

Abstract

During the coagulation process, blood changes from a liquid to a solid gel phase. These changes are reflected by changes in blood viscosity; however, blood viscosity at different shear rates (SR) has not been previously explored during the coagulation process. In this study, we investigated the viscosity changes of whole blood in 10 subjects with a normal coagulation profile, using a cone-on-plate viscosimeter. For each subject, three consecutive measurements were performed, at a SR of 20, 40, 80 sec−1. On the basis of the time-dependent changes in blood viscosity, we identified the gel point (GP), the time-to-gel point (TGP), the maximum clot viscosity (MCV), and the clot lysis half-time (CLH). The TGP significantly (P = 0.0023) shortened for increasing SR, and was significantly associated with the activated partial thromboplastin time at a SR of 20 sec−1 (P = 0.038) and 80 sec−1 (P = 0.019). The MCV was significantly lower at a SR of 80 sec−1 versus 40 sec−1 (P = 0.027) and the CLH significantly (P = 0.048) increased for increasing SR. These results demonstrate that measurement of blood viscosity during the coagulation process offers a number of potentially useful parameters. In particular, the association between the TGP and the activated partial thromboplastin time is an expression of the clotting time (intrinsic and common pathway), and its shortening for increasing SR may be interpreted the well-known activating effects of SR on platelet activation and thrombin generation. Further studies focused on the TGP under conditions of hypo- or hypercoagulability are required to confirm its role in the clinical practice.

Ancillary