Giant Abdominal Haematoma and Rapid Multidrug-Resistant Infection After Low-Molecular-Weight Heparin in a Patient With COVID-19 and Rheumatoid Arthritis

Chuan Sun,1,* Xiao Zheng,2,* Hui Wang,2 Shaoling Xu11Department of Medical Affairs, Zhaoyuan Hospital of Traditional Chinese Medicine, Yantai, Shandong, People’s Republic of China; 2Department of Critical Care Medicine, Zhaoyuan People’s Hospital, Yantai, Shandong, People’s Republic of China*These authors contributed equally to this workCorrespondence: Hui Wang, Email 861280414@qq.com Shaoling Xu, Email 1085518636@qq.comBackground: Low-Molecular-Weight Heparin (LMWH) is a widely used anticoagulant in clinical practice during the COVID-19 pandemic. However, the risk of adverse reactions increases significantly in patients with multiple underlying diseases and immune dysfunction. This article reports a case of a patient with COVID-19 complicated with rheumatoid arthritis who had long-term oral prednisone (5 mg/d) for rheumatoid arthritis, who developed a rare giant hematoma (15cm× 15cm) after LMWH administration, which rapidly progressed to sequential infections caused by multidrug-resistant organisms, including extended-spectrum β-lactamase (ESBL)-producing Escherichia coli and carbapenem-resistant Acinetobacter baumannii (CRAB), within one day. This case describes the complexity and severity of adverse drug reactions under the superposition of multiple factors, and offers clinical insights for diagnosis and management.Case Summary: A 61-year-old female patient was admitted to the hospital for treatment of "viral pneumonia and COVID-19”. Her underlying diseases included rheumatoid arthritis (long-term oral prednisone 5mg/d), hypertension, and type 2 diabetes mellitus. After admission, the patient was given subcutaneous injection of LMWH (2500 IU, qd) for anticoagulation, combined with Simnotrelvir/Ritonavir for antiviral treatment. On the 9th day of medication, a giant hematoma of about 15cm× 15cm appeared at the LMWH injection site; on the 10th day of medication, the hematoma rapidly developed into severe soft tissue infection, and the infection further spread to both waists. Etiological examination successively detected extended-spectrum β-lactamase (ESBL)-producing Escherichia coli and carbapenem-resistant Acinetobacter baumannii (CRAB). The total length of hospital stay was 84 days (excluding 2 days of outpatient observation during inter-hospital transfers). During this period, the patient received multiple rounds of anti-infective treatment with meropenem, linezolid, minocycline, etc. and underwent 5 debridements, Vacuum Sealing Drainage (VSD), and skin grafting. After active treatment, the patient’s infection was finally effectively controlled, and she was discharged smoothly after wound healing.Conclusion: Under the superposition of multiple immunosuppressive factors such as COVID-19, long-term prednisone use and additional in-hospital glucocorticoid therapy, conventional-dose LMWH can induce an unusually large hematoma (15cm× 15cm), with rapid disease progression (secondary infection within 1 day), which is prone to refractory MDROs infection. For such high-risk patients, clinical practice should formulate highly individualized anticoagulant treatment plans and further strengthen the monitoring of adverse reactions.Keywords: low-molecular-weight heparin, adverse drug reaction, giant hematoma, rapid progression, COVID-19, rheumatoid arthritis, glucocorticoids, multidrug-resistant organisms, MDROs