Cirrhosis and Liver Failure
Global hemostasis tests in patients with cirrhosis before and after prophylactic platelet transfusion
Armando Tripodi, Via Pace 9, 20122-Milano, Italy
Tel: +39 02 503 20725
Fax: +39 02 503 20723
Cirrhosis presents with variable degrees of thrombocytopenia that might cause bleeding during invasive procedures. Transfusion of one standard adult platelet dose is often employed to prevent bleeding in thrombocytopenia, but the threshold platelet count that is clinically effective is not well established because clinical studies and laboratory tools to judge on efficacy are insufficient. However, in vitro studies showed that patients with cirrhosis generate as much thrombin as healthy individuals provided that their platelet count is at least 100 × 109/L.
To assess the in vivo relevance of these in vitro studies, we investigated 26 thrombocytopenic patients with cirrhosis, undergoing 36 variceal ligations, to see whether transfusion of one standard adult platelet dose was able to attain the above platelet count. We also evaluated the effect of platelet transfusion on such global hemostasis tests as thrombin generation and thromboelastometry.
Transfusion did slightly increase platelet count [pre- vs. post-infusion: 39 × 109/L(16-64) vs. 52 × 109/L(19-91), P < 0.001], without significant effect on thrombin generation, probably because post-transfusion platelet count was less than the target of 100 × 109/L in all patients. In addition, the percentage of patients with abnormal thrombin generation (i.e. below the lower limit of normal range) was scarcely affected by transfusion (pre- vs. post-infusion: 36% vs. 42%). The small post-transfusion increase in platelet count was paralleled by some degree of improvement of thromboelastometry, but none of the patients reached normal values after transfusion.
Infusing one standard adult platelet dose secures only a small increase in platelet count without normalizing thrombin generation and thromboelastometry tests. To obtain greater increases in platelet count and normalization of laboratory tests more intensive platelet transfusions or treatment with non-transfusional drugs are probably needed.