The last 2 chapters of the guidelines for managing venous thromboembolism (VTE) that have been released by the American Society of Hematology (ASH) cover VTE management strategies for both pediatric and pregnant patients.
VTE in Pediatric Patients
In the general pediatric population, the incidence of VTE ranges from 0.07 to 0.14 per 10,000 children, but the incidence is dramatically increased by 100 to 1000 times in hospitalized children.1 Idiopathic VTE in the pediatric population is relatively rare and is almost always associated with an underlying disease or risk factor. The most common age groups for VTE are neonates and teenagers, and the most common precipitating cause is the presence of a central venous catheter, which is responsible for 90% of VTE events detected in neonates and approximately 60% of VTE events in children.
Treating VTE in children can be challenging as the natural histories of many types of thrombus remain unclear, and no anticoagulant drugs have been approved in this population. Specific research in pediatrics is very limited, and much of the evidence for treatment is extrapolated from adult practice. This can be problematic because of the major differences between adults and children regarding epidemiology and pathophysiology of thrombosis, the physiology of the coagulation system, and the influence of these differences on the pharmacology of antithrombotic agents.
The panel agreed on 30 recommendations covering symptomatic and asymptomatic deep vein thrombosis and also included a specific focus on managing central venous access device-associated VTE.
Some of the recommendations include:
- Anticoagulation should be used in pediatric patients with symptomatic deep vein thrombosis or pulmonary embolism.
- Thrombolysis followed by standard anticoagulation should not be used in neonates with nonlife-threatening renal vein thrombosis. Instead, anticoagulation should be used alone.
- Removal of a nonfunctioning or unneeded central venous catheter is recommended in pediatric patients with symptomatic catheter-related thrombosis.
- Using an anticoagulant is recommended in patients with cerebral sino venous thrombosis without hemorrhage.
The guidelines also included a good practice statement noting that a pediatric hematologist or a pediatrician in consultation with a hematologist would be best suited to implement these recommendations, given the complexity of the care involved in the treatment of children with VTE.
VTE in the Context of Pregnancy
Pregnancy is associated with a 5- to 10-fold increase in risk for VTE, complicates approximately 1.2 of every 1000 pregnancies, and is a leading cause of maternal morbidity and mortality in the United States.2 The main reason for this higher risk is hypercoagulability, which may present as early as the first trimester. Other risk factors include a history of thrombosis, inherited and acquired thrombophilia, certain medical conditions, and complications of pregnancy and childbirth. Both prevention and treatment of VTE are complicated in pregnancy because of the need to consider the fetus as well as the mother. The new ASH guidelines address these challenging issues.