Spontaneous psoas haematoma: a life-threatening complication of anticoagulation in COVID-19. A case series of four episodes

Background: Anticoagulant prophylaxis is part of the standard management of hospitalized COVID-19 patients. Despite adequate thromboprophylaxis, one-third of COVID-19 patients with pneumonia developed pulmonary embolism. This high rate of thrombotic complications has led to higher doses of anticoagulants according to clinical complexity (e.g. intensive care unit (ICU) patients) and D-dimer levels. On the other side of the coin, haemorrhagic complications are being increasingly reported. Cases presentation: We herein report four cases of spontaneous psoas haematomas (SPH) among 548 patients hospitalized for SARS-CoV-2 pneumonia between March 2020 and January 2021 (incidence of 7.3 cases per 1000 patients). All patients had pneumonia, with age ranging between 62 and 83 years. All patients received anticoagulant therapy with low weight molecular heparin (100 U.I. anti-Xa/kg 2 times/d) from admission: in two cases, a diagnosis of pulmonary embolism was made. In another case, a thrombosis of left axillary and basilic veins was found, and only in one case anticoagulant therapy was started because of elevated levels of D-dimer. In all cases, signs of anaemia were detected and patients experienced low back or abdominal pain. The diagnosis of spontaneous psoas haematoma was made by computed tomography (CT) after a median of 12.5 d (9;16) from admission and 19.5 d (14.75; 24.25) from the beginning of COVID-19 symptoms. Half of these patients died from haemorrhagic shock. Conclusions: Given the potential life-threatening of SPH and the possible subtle clinical presentation, we believe it is crucial to raise clinicians awareness of this complication among COVID-19 patients undergoing anticoagulants.