Discussion:
Novel COVID-19 first originated from Wuhan, China and has spread rapidly to all over the world.1 It spreads via respiratory droplets between close contacts and patients usually present with respiratory symptoms although atypical symptoms like altered mental status in elderly patients have been reported.2 There have been increased evidence of hypercoagulability seen in patients infected with COVID-19. Venous thromboembolism (VTE) is common in acutely ill patients with COVID-19 and has been termed as COVID-19-associated coagulopathy (CAC).3 An autopsy study showed as high as 58% incidence of VTE.4 The pathogenesis of CAC is incompletely understood. All three categories of ‘Virchow’s triad’ appears to be implicated including, endothelial injury as evident by direct invasion of endothelial cells by the virus along with increased cytokines and complements, stasis due to immobilization in hospitalized patients and hypercoagulable state due to changes in circulating prothrombotic factors such as D-dimer and fibrinogen.5 Risk factors for CAC are males with obesity and other chronic medical comorbidities, especially cardiovascular disease, hypertension, diabetes mellitus and ESRD.4 Common laboratory findings include high D-dimer and fibrinogen, mildly prolonged PT and aPTT and mild thrombocytopenia.4 Elevated D-dimer levels appears to correlate with illness severity as well as increased mortality.
CAC appears to clinically behave differently from disseminated intravascular coagulation (DIC).3 The major clinical finding in CAC is thrombosis and high fibrinogen, whereas acute DIC often presents with bleeding and low fibrinogen.3Management can be challenging due to absence of high-quality data. Whether therapeutic dose anticoagulation should be offered to everyone with COVID-19 remains unclear. Some authors have suggested using intermediate dose of low molecular weight heparin in patients with significantly elevated d-dimer levels due to the high percentage of patients with VTE despite receiving prophylactic anticoagulation.6,7 Full-dose anticoagulation is recommended for individuals with documented VTE or with recurrent clotting of intravascular access devices unless contraindicated.