Key Points• DDAVP is the drug of choice for mild hemophilia A and von Willebrand disease and (by unclear mechanisms) for platelet function disorders.• In vivo DDAVP selectively and markedly enhances the ability to form procoagulant platelets by enhancing intracellular Na 1 and Ca 21 fluxes.is clinically efficacious in patients with mild platelet function disorders but it is not known which mechanisms mediate this effect. Our aim was to evaluate the impact of in vivo DDAVP administration in these patients. We assessed von Willebrand factor (VWF), factor VIII, platelet activation and aggregation, platelet-dependent thrombin generation, and platelet intracellular Na 1 /Ca 21 fluxes, before and 2 and 4 hours after DDAVP (0.3 mg/kg). We found (1) no significant changes for P-selectin expression, PAC-1 binding, d-granule content and secretion, and platelet-aggregation; (2) significant decreases of secretion of a-granules and GPIIb-IIIa activation induced by adenosine 59-diphosphate, convulxin, and thrombin; (3) significant increases of procoagulant platelets induced by convulxin/thrombin and platelet-dependent thrombin generation; and (4) significant increases of intracellular Na 1 /Ca 21 concentrations. We show that in vivo DDAVP selectively and markedly enhances the ability to form procoagulant platelets and increases platelet-dependent thrombin generation by enhancing Na

BackgroundThrombin generation (TG) assays evaluate the balance between pro‐ and anticoagulant forces, to better assess bleeding and thrombotic risks. Although TG readouts obtained with the calibrated automated TG have been investigated in multiple clinical conditions, TG still needs standardization and clinical validation. The automated TG instrument ST Genesia® (STG, Stago, Asnières‐sur‐Seine, France) provides a normalization of TG parameters based on a reference plasma aiming to reduce the interlaboratory variability and the variability between different measurement runs.ObjectivesTo evaluate STG in a group of healthy adults.MethodsReference intervals in healthy adults and variability of the new standardized reagents for bleeding (BleedScreen) and thrombophilic (ThromboScreen) conditions were determined using STG.Results TG was measured in platelet‐free plasma (PFP) samples of 123 healthy adults. Reference intervals were determined for TG parameters. Intra‐ and interassay coefficients of variation were calculated on quality controls and PFP samples from healthy adults. Oral contraception (OC) possibly influenced TG parameters, resulting in a higher median and a broader reference interval for peak height and endogenous thrombin potential (ETP) in women aged 20 to 49 years than in all other sex and age categories. Therefore, we propose the following reference interval categories: men, women aged <50 years not using OC, women aged <50 years using OC, and women aged ≥50 years. Normalization was effective to reduce the interassay variability of quality controls for ETP (BleedScreen assay), and peak height and ETP (ThromboScreen assay without thrombomodulin), but had little impact on PFP sample variability.Conclusion STG appears suitable for accurate measurement of TG in healthy adults.

At our institution, transport of blood samples by pneumatic delivery does not influence ROTEM(®) parameters. Blood samples can be analysed centrally, and results transmitted live via virtual network computing to emergency or operating rooms. Prior to analyse blood samples centrally, the type of sample transport should be tested to exclude in vitro blood activation by local pneumatic transport system.