In December 2019, a new coronavirus disease called COVID-19 emerged in Wuhan, China. It was declared a pandemic by the World Health Organization in March 2020. COVID-19 can cause a range of symptoms, from no symptoms to severe lung injury. Some patients may also have concomitant viral infections or bacterial pneumonia. Studies have shown that non-survivors of COVID-19 often exhibit sepsis, respiratory failure, acute respiratory distress syndrome (ARDS), and septic shock, indicating multi-organ involvement. Inflammation, particularly in the form of a cytokine storm, is considered a major factor in the disease, but other pathways such as hypercoagulation and endothelial cell dysfunction have also been implicated.
Disseminated intravascular coagulation (DIC) and macrovascular thrombosis can occur in severe cases, leading to significant morbidity and mortality. Older patients and those with comorbidities are at higher risk of in-hospital mortality and often have higher levels of D-dimer. The risk of thrombosis in COVID-19 patients can persist for several weeks, potentially leading to rehospitalization and sudden deaths.