[Effectiveness of thromboprophylaxis with low molecular weight heparin in critically ill patients with COVID-19. An observational prospective, multicenter study].

Introduction: COVID-19 induces coagulopathy associated with an increase of thromboembolic events. Due to the lack of agreement on recommendations for thromboprophylactic management, the aim of this study was to study the dosages of LMWH used in critically ill COVID-19 patients assessing the effect on their outcome. Metohds: We evaluated data of the Reg-COVID19. According to LMWH dose two groups were analyzed: prophylaxis and treatment. Primary outcome was the relationship of LMWH dosage with mortality. Secondary outcomes included the incidence of thrombotic and bleeding events, length of ICU stay, invasive mechanical ventilation, and thrombotic and inflammatory parameters. Results: Data of 720 patients were analyzed, 258 in the prophylaxis group and 462 in the treatment group. C Reactive Protein, invasive mechanical ventilation, tocilizumab and corticosteroid treatments were related with the choice of LMWH dose. Hemorrhagic events (66/720, 9.2%) and thrombotic complications (69/720, 9.6%) were similar in both groups ( Conclusion: We found no benefit or harm with the administration of therapeutic or prophylactic LMWH dose in COVID19 critically ill patients. With a similar rate of hemorrhagic or thrombotic events, the LMWH dose had no influence on mortality. More studies are needed to determine the optimal thromboprophylaxis protocol for critically ill patients.