Thromboembolic prevention and anticoagulant therapy during the COVID-19 pandemic: updated clinical guidance from the anticoagulation forum.

Thromboembolism is a common and deadly consequence of COVID-19 infection for hospitalized patients. Based on clinical evidence pre-dating the COVID-19 pandemic and early observational reports, expert consensus and guidance documents have strongly encouraged the use of prophylactic anticoagulation for patients hospitalized for COVID-19 infection. More recently, multiple clinical trials and larger observational studies have provided evidence for tailoring the approach to thromboprophylaxis for patients with COVID-19. This document provides updated guidance for the use of anticoagulant therapies in patients with COVID-19 from the Anticoagulation Forum, the leading North American organization of anticoagulation providers. We discuss ambulatory, in-hospital, and post-hospital thromboprophylaxis strategies as well as provide guidance for patients with thrombotic conditions who are considering COVID-19 vaccination.

Thromboembolism and anticoagulant therapy during the COVID-19 pandemic: interim clinical guidance from the anticoagulation forum.

Coronavirus disease 2019 (COVID-19) is a viral infection that can, in severe cases, result in cytokine storm, systemic inflammatory response and coagulopathy that is prognostic of poor outcomes. While some, but not all, laboratory findings appear similar to sepsis-associated disseminated intravascular coagulopathy (DIC), COVID-19- induced coagulopathy (CIC) appears to be more prothrombotic than hemorrhagic. It has been postulated that CIC may be an uncontrolled immunothrombotic response to COVID-19, and there is growing evidence of venous and arterial thromboembolic events in these critically ill patients. Clinicians around the globe are challenged with rapidly identifying reasonable diagnostic, monitoring and anticoagulant strategies to safely and effectively manage these patients. Thoughtful use of proven, evidence-based approaches must be carefully balanced with integration of rapidly emerging evidence and growing experience. The goal of this document is to provide guidance from the Anticoagulation Forum, a North American organization of anticoagulation providers, regarding use of anticoagulant therapies in patients with COVID-19. We discuss in-hospital and post-discharge venous thromboembolism (VTE) prevention, treatment of suspected but unconfirmed VTE, laboratory monitoring of COVID-19, associated anticoagulant therapies, and essential elements for optimized transitions of care specific to patients with COVID-19.

Early ambulation after acute deep vein thrombosis: is it safe?

The number of thrombotic events in children, although significantly less than that in adults, is increasing as a result of therapeutic advances in primary illnesses that were previously fatal. When a patient, adult or pediatric, develops a deep vein thrombosis and anticoagulation therapy is initiated, many health professionals ask, "When should this patient have physical therapy and/or ambulate?" Fear of causing a pulmonary embolism with increased activity drives this question. Often, an order for bed rest is prescribed based more on tradition than on evidence-based medicine. A review of the literature has provided an evidence-based answer to the question, and although the studies are all of adult populations, the results have been extrapolated for use with comparable pediatric populations. The majority of studies agree that early ambulation does not increase an anticoagulated patient's risk for pulmonary embolism. Moreover, most studies report that early ambulation carries benefits such as decreased pain and swelling and fewer postthrombotic syndrome symptoms.

May-Thurner syndrome (iliac vein compression) and thrombosis in adolescents.

May-Thurner syndrome refers to anatomic compression of the left iliofemoral vein by the overriding right iliac artery. We report three adolescents who presented to our pediatric hospital with iliac vein thrombosis and were diagnosed with May-Thurner syndrome. Each received catheter-directed thrombolysis followed by balloon angioplasty to restore flow. Two patients had endovascular stents placed. The procedures were well tolerated, without major complications. Additional thrombophilic risk factors were identified in each patient. Though uncommon, pediatric hematologists should consider May-Thurner syndrome in adolescents who present with a left lower extremity thrombosis. Aggressive therapy may be warranted due to the risk of post-thrombotic syndrome.

Cystic fibrosis as a risk factor for recurrent venous thrombosis at a pediatric tertiary care hospital.

OBJECTIVE: To evaluate risk factors for recurrent thrombosis in pediatric patients. STUDY DESIGN: This prospective observational cohort study enrolled 120 patients with acute venous thromboembolism from January 2003 to April 2005. Data collection included medical and family history, radiologic and laboratory studies, therapy, and follow-up. RESULTS: The overall prevalence of recurrent thrombosis in our cohort was 19/120 (15.8%). Patients with recurrence were older, with a median age of 14.8 years (range 2 weeks-23.6 years), compared with 10.1 years (range newborn 23.4 years) in patients without recurrence (P = .03). Six of the 19 patients with recurrent thrombosis had cystic fibrosis (CF), compared with 0/101 without recurrence (P < .001). Five of these 6 patients were colonized with Burkholderia cepacia in their sputum. Central venous catheters were associated with most, but not all, of the thromboses in patients with CF. CONCLUSIONS: In this study, patients with CF had a high risk of recurrent venous thrombosis, as well as a high prevalence of colonization with B cepacia. The cause of this risk has not been defined. This observation may have important implications for thromboprophylaxis, particularly in the setting of central venous catheters.