Materials and Methods: We retrospectively analyzed 54 patients who were anticoagulated with low- molecular-weight heparin (LMWH) and developed RPB during COVID-19 treatment in the hospital, either in intensive care unit or non-intensive care unit services, between March 2020 and March 2021. The patients' demographic and clinical data were analyzed, and we compared the laboratory results at the time of admission and during episodes of RPB. The patients were divided into conservative and interventional treatment groups. We compared the size of retroperitoneal hematoma, anticoagulant doses, erythrocyte suspension transfusion rates, presence of hyperinflammation syndrome between these groups. Also, treatment modalities and mortality status were shown. The hematoma size and erythrocyte suspension transfusion rates were compared between groups, and their correlation with anticoagulant dose and age were analyzed as well.

Results: In the management of RPB that developed, 48 (88.9%) patients were approached conservatively, 4 (7.4%) patients underwent angioembolization, and 2 (3.7%) patients laparotomy. Mortality was observed in 14 (25.9%) patients. Relevant laboratory parameters as lactate dehydrogenase, procalcitonin, interleukin-6 levels and lymphocyte counts were elevated exceedingly, while the hemogram test values were significantly lower during episodes of RPB (p=0.007, p=0.044, p=0.031, p=0.018 and p<0.001, respectively). Also, there was a significant correlation between increased LMWH doses and size of the hematomas (p=0.044).

Conclusion: Patients experiencing RPB while receiving anticoagulants due to COVID-19 need active treatment depending on the dose of anticoagulants they are using. Considering the patient's clinical need, it may be a logical approach to start treatment with the lowest possible dose of an anticoagulant.