Hirudin Versus Citrate As an Anticoagulant for ROTEM Platelet Whole Blood Impedance Aggregometry in Thrombocytopenic Patients.

Plain Language Summary Citrate is the most commonly used anticoagulant for coagulation studies including rotational thromboelastometry (ROTEM). Hirudin is an alternative option to be used as an anticoagulant for PFTs because of the inhibitory effect of citrate on platelet function. One study (Nissen et al. (2020)) reported higher precision and platelet aggregation with hirudinized blood of healthy individuals, over citrate using ROTEM platelet. However, none of the studies were performed in patients in actual clinical context. We evaluated the potential benefit of using hirudin anticoagulated blood over citrate in thrombocytopenic patients due to Dengue hemorrhagic fever using ROTEM platelet. We observed higher platelet aggregation with hirudin compared to citrate suggesting the importance of using hirudin anticoagulation in PFTs, particularly in patients with severe thrombocytopenia. Citrate is widely used as an anticoagulant for platelet function tests (PFTs). Due to an intrinsic inhibitory effect of citrate on platelet function, hirudin is used as an alternative. However, studies comparing the effect of these anticoagulants on rotational thromboelastometry (ROTEM) platelet whole blood impedance aggregometry in thrombocytopenic patients are scant. Cross-sectional study was done in 105 patients who entered the critical phase of Dengue hemorrhagic fever with plasma leakage and severe thrombocytopenia (<100 x 10(9)/L). Samples were collected on two consecutive days and considered as a combined data set for analysis, out of which 200 have been included in the data analysis. Platelet count was used from routine full blood count. ROTEM platelet used TRAPTEM assay, which was performed with 3.2% sodium citrate and 525 ATU/ml hirudin anticoagulated blood. Means of all the TRAPTEM parameters were significantly higher in hirudin, compared to citrate samples (p < .05). Significantly higher overall platelet aggregation was observed in hirudinized samples with a significant mean difference (p < .05) compared to citrate in each quartile of platelet count. Higher platelet aggregation was observed with hirudin compared to citrate in ROTEM platelet whole blood impedance aggregometry in thrombocytopenic patients elaborating the importance of using hirudin anticoagulation in PFTs, particularly in patients with severe thrombocytopenia.