The effects of aprotinin on thromboelastography with three different activators

Background: Thromboelastography is used for assessment of hemostasis. Adher ence to thromboelastography-guided algorithms and aprotinin administration each decrease bleeding and blood product usage after cardiac surgery. Aprot inin, through inhibition of kallikrein, causes prolongation of the celite-a ctivated clotting time and the activated partial thromboplastin ratio. The aim of this study was to assess the effects of aprotinin on the thromboelas tography trace. Methods. Three activators were used in the thromboelastography: celite (whi ch is widely established), kaolin, and tissue factor. Assessment was perfor med on blood from volunteers and from patients before and after cardiac sur gery. Results: The tissue factor-activated thromboelastography trace was unaffect ed by the addition of aprotinin. When celite and kaolin were used as activa tors in the presence of aprotinin, the reaction time (time to clot formatio n) of the thromboelastography trace was prolonged (P < 0.0001) and the maxi mum amplitude (clot strength) was decreased (P < 0.05). With celite as an a ctivator, the addition of aprotinin decreased (P < 0.05) the thromboelastog raphy a angle (rate of clot extension). The reaction time of the celite-act ivated trace correlated with the activated partial thromboplastin ratio (P < 0.01). The reaction time of the tissue factor-activated trace correlated with the international normalized ratio (P < 0.01). Conclusion: The thromboelastography trace is altered in the presence of apr otinin when celite and kaolin are used as activators but not when tissue fa ctor is the activator.