Abstract
Spontaneous retroperitoneal hematoma and rectus sheath hematoma (SRH/RSH) are rare
hemorrhagic events. Some of the risk factors for SRH/RSH are similar to those of the severity of
coronavirus disease 2019 (COVID-19) or associated with the management of COVID-19. Among
201 COVID-19 patients aged over 65 years who received anticoagulant therapy for COVID-19
between March 2020 and February 2022, 4 patients developed SRH/RSH during hospitalization.
SRH/RSH occurred 6‒14 days after the initiation of anticoagulation therapy. All 4 patients
developed SRH/RSH while under administration of a prophylactic dose of unfractionated heparin
(UFH) and dexamethasone for severe COVID-19, within the target range of the activated partial
thromboplastin time (APTT). All 4 patients discontinued UFH, 3 underwent transfusion therapy,
and 1 underwent angiographic intervention with embolization；2 died：1 from disseminated
intravascular coagulation and the other from respiratory failure due to COVID-19. The other 2
were discharged 66 and 38 days after the onset of SRH/RSH. SRH/RSH can occur even within the
expected range of APTT and can contribute to poor outcomes in COVID-19 patients.
