LMWH Dosing for Pediatric CSVT
For children with cerebral sinus venous thrombosis, enoxaparin should be dosed at 1.0 mg/kg subcutaneously every 12 hours, adjusted to maintain anti-factor Xa levels between 0.5-1.0 units/mL measured 4 hours post-injection. 1
Age-Specific Dosing Considerations
- Neonates require substantially higher doses than older children, averaging 1.6 mg/kg every 12 hours to achieve therapeutic anti-Xa levels, due to increased extravascular clearance in this age group 1, 2
- Older children and adolescents typically achieve target levels with the standard 1.0 mg/kg every 12 hours dosing 1
Monitoring Protocol
- Anti-factor Xa levels should be measured 4 hours post-injection to assess therapeutic adequacy 1
- After initial dose adjustment to achieve therapeutic range, monitor anti-Xa levels twice weekly to balance safety with reduced monitoring burden compared to unfractionated heparin 1
- Target anti-Xa range is 0.5-1.0 units/mL for therapeutic anticoagulation 1
Critical Context: 6 Weeks vs. Standard Duration
Important caveat: The 6-week duration mentioned in your question applies primarily to neonates, NOT to older children. 1
- For non-neonatal children with CSVT, the American College of Chest Physicians recommends a minimum of 3 months of anticoagulation with LMWH or vitamin K antagonist 3
- For neonates specifically, guidelines suggest 6 weeks to 3 months of total anticoagulation therapy 1
- Stopping at 6 weeks in older children is premature unless there is documented complete resolution and the patient is a neonate 1, 4
When to Extend Beyond Minimum Duration
Consider extending anticoagulation to 6 months total if: 3, 4
- Persistent CSVT occlusion remains after initial 3-month treatment period
- Ongoing neurologic symptoms persist
- Potentially recurrent risk factors exist (e.g., nephrotic syndrome, asparaginase therapy)
Hemorrhage Is NOT a Contraindication
- Do not withhold anticoagulation solely due to hemorrhage if it results from venous congestion, as this represents the pathophysiology of CSVT itself rather than a bleeding diathesis 1, 4
- If significant hemorrhage is present, either initiate anticoagulation as planned OR perform radiologic monitoring at 5-7 days and anticoagulate if thrombus extension occurs 3
Common Pitfall to Avoid
The most critical error is stopping anticoagulation prematurely at 6 weeks in non-neonatal children. This duration is insufficient for most pediatric CSVT cases, which require a minimum of 3 months unless the patient is a neonate with complete resolution 1, 4