Summary: The concept of haemostatic resuscitation implies early and high‐volume plasma transfusion. We investigated the haemostatic profile of reconstituted whole blood prepared in a 1:1:1 ratio of blood, platelets and plasma. This consisted of packed red blood cells, platelet concentrate and four different plasma variants: fresh frozen; solvent‐detergent; lyophilised quarantine; and lyophilised methylene blue‐inactivated plasma. Haematocrit, platelet count, endogenous thrombin potential and coagulation factor activity were significantly lower in reconstituted blood compared with citrated whole blood (p < 0.01). Except for lyophilised methylene blue‐inactivated plasma, no substantial differences between plasma variants in coagulation factor activity, endogenous thrombin potential and standard coagulation tests were observed. After reconstitution, haematocrit and platelet counts were slightly above recommended transfusion triggers, most thromboelastometry ( ROTEM ^® ) parameters were within the normal range and fibrinogen concentrations were between 1.57 g.l ⁻¹ and 1.91 g.l ⁻¹ . Reconstitution of whole blood in a 1:1:1 ratio resulted in significant dilution of haematocrit and platelet count, but values remained above limits recommended by transfusion guidelines. Fibrinogen concentrations of reconstituted whole blood were also significantly reduced, and these were below the threshold value for supplementation recommended by recent guidelines.

Extracorporeal membrane oxygenation (ECMO) is gaining importance in the perioperative management of lung transplant patients. To date, the ideal substance for anticoagulation of ECMO patients is still a matter of debate. In this study, we describe our experience with the use of low molecular weight heparin (LMWH) in comparison with unfractioned heparin (UFH) in lung transplant patients undergoing perioperative ECMO support. We retrospectively analyzed data from all lung transplant patients who underwent perioperative ECMO support at our institution between 2013 and 2017. Bleeding events served as primary outcome parameter. Secondary outcome parameters consisted of thromboembolic events. 102 patients were included in this study, of which 22 (21.6%) received UFH for anticoagulation, and 80 (78.4%) received LMWH. There was no difference between the two groups in regard to serious bleeding events (22.7% in the UFH group vs 12.5% in the LMWH group, P = .31). However, the proportion of patients experiencing thromboembolic events was significantly higher in the UFH group than in the LMWH group (50% vs 20%, P = .01). After adjusting for baseline differences between the two groups, we still observed a difference with respect to thromboembolic events. These data remain to be validated in future prospective, randomized trials.

Background: Viscoelastic coagulation testing has been suggested to help manage coagulopathy in critically ill patients with COVID-19. However, results from different viscoelastic devices are not readily comparable. ClotPro® is a novel thromboelastometry analyzer offering a wider range of commercially available assays.Methods: We compared the results from ClotPro with results from the well-established ROTEM® Delta device and conventional coagulation tests in critically ill patients with COVID-19.Results: Viscoelastic parameters indicated the presence of a potentially hypercoagulable state in the majority of patients. In up to 95 paired measurements, we found strong correlations between several parameters routinely used in clinical practice: (i) EX test vs. EXTEM CT, A5, A10, MCF, (ii) IN test vs. INTEM A5, A10, MCF, and (iii) FIB test vs. FIBTEM A5, A10, MCF (all R > 0.7 and p < 0.001). In contrast, IN test CT vs. INTEM CT showed only a moderate correlation (R = 0.53 and p < 0.001). Clot strength parameters of both devices exhibited strong correlations with platelet counts and fibrinogen levels (all R > 0.7 and p < 0.001). Divergent correlations of intrinsically activated assays with aPTT and anti-factor Xa activity were visible. Regarding absolute differences of test results, considerable delta occurred in CT, CFT, and clot strength parameters (all p < 0.001) between both devices.Conclusions: Several parameters obtained by ClotPro show strong correlations with ROTEM Delta. Due to weak correlations of intrinsically activated clotting times and considerable absolute differences in a number of parameters, our findings underline the need for device-specific algorithms in this patient cohort.

Guidelines for the treatment of severe bleeding comprise viscoelastic-test-guided use of coagulation factor concentrates as part of their recommendations. The aim of this study is to investigate the effects of substituting fibrinogen, prothrombin complex concentrate, and a combination of both on conventional coagulation tests, viscoelastic test results, and thrombin generation. Blood was drawn from seven healthy volunteers to obtain platelet-free plasma, which later was diluted by replacing 40%, 60%, 80%, 90%, 95%, and 99% with a crystalloid solution. The diluted samples were spiked with fibrinogen concentrate, prothrombin complex concentrate, a combination of both, or a corresponding amount of crystalloid solution. Up to a dilution level of 95%, viscoelastically determined clotting time was significantly shorter in the group substituted with fibrinogen only in comparison with the additional use of prothrombin complex concentrate. Clot firmness and endogenous thrombin potential remained at relatively stable values up to a dilution level of 95% with the substitution of fibrinogen but not prothrombin complex concentrate. Substitution of prothrombin complex concentrate led to an excessive overshoot of thrombin generation. The results of our study question currently propagated treatment algorithms for bleeding patients that include the use of prothrombin complex concentrate for patients without former intake of oral anticoagulants. Even in severely bleeding patients, thrombin generation might be sufficient to achieve adequate hemostasis.

BACKGROUND Platelet concentrates (PCs) are usually stored at room temperature under constant gentle agitation. Risk of bacterial contamination limits maximum storage time to 5 days. The objective of the study was to investigate platelet function with regard to storage time in different reconstituted whole blood (RWB) variants. METHODS Donated apheresis PCs were stored at 22 degrees C over 5 days. To obtain RWB, apheresis PCs were mixed with plasma-free packed red blood cells (RBCs) and either prethawed fresh frozen plasma (PT) or solvent-detergent plasma (SD) [1:1:1 ratio], or with leukocyte- and platelet-depleted whole blood (LD-WB) as control. Platelet function in RWB variants was assessed by impedance aggregometry (Multiplate) on Days 0, 1, 3, and 5 following platelet donation. RESULTS Platelet aggregometry did not reach the lower limits determined from healthy volunteers in any of the RWB variants. Platelet aggregability measured by ASPI test, ADP test, and COL test declined over storage time in all RWB variants. No differences were observed in the TRAP test. At most measurement time points, LD-RWB provided significantly higher platelet aggregability compared with SD-RWB and PT-RWB (p < 0.01). SD-RWB demonstrated higher platelet aggregability on Day 0 in the ASPI test, ADP test, and TRAP test compared with PT-RWB. CONCLUSION Apheresis PCs stored for 5 days at 22 degrees C demonstrated reduced platelet aggregability, as measured by multiple electrode aggregometry when mixed with RBCs and plasma. As platelet aggregation in LD-RWB was superior compared with SD-RWB and PT-RWB variants, it might be possible that additives in RBCs or plasma are responsible for the observed depressed platelet function. Critical evaluation of current massive transfusion recommendations proposing early platelet transfusion is indicated.