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Antithrombin concentrate in pediatric patients requiring unfractionated heparin anticoagulation: a retrospective
Lindsay M Ryerson1, Mary E Bauman, Stefan Kuhle
11Pediatric Critical Care, Stollery Children Hospital, University of Alberta, Edmonton, AB, Canada. 2Pediatric Cardiology-Thrombosis, Stollery Children's Hospital, University of Alberta, Edmonton, AB, Canada. 3Departments of Pediatrics and Obstetrics and Gynaecology, Dalhousie University, Halifax, NS, Canada. 4Department of Hematology, Stollery Children's Hospital, University of Alberta, Edmonton, AB, Canada. 5Pediatric Cardiology-Thrombosis, Stollery Children's Hospital, Edmonton, AB, Canada.
Insights
High-dose antithrombin concentrate effectively increased antithrombin levels in pediatric patients. This treatment allowed for lower unfractionated heparin doses while maintaining therapeutic anti-factor Xa activity, with no adverse events observed.
Area of Science:
- Pediatric Hematology
- Pharmacology
- Critical Care Medicine
Background:
- Antithrombin concentrate is used to manage heparin resistance in pediatric patients.
- Understanding its efficacy and safety in children is crucial for anticoagulation management.
Purpose of the Study:
- To evaluate antithrombin levels, unfractionated heparin effect, and adverse events following a single high dose of antithrombin concentrate in pediatric patients.
- To assess the impact of antithrombin concentrate on anticoagulation parameters and safety in a pediatric population.
Main Methods:
- Retrospective review of pediatric patients with antithrombin levels <50% and subtherapeutic unfractionated heparin effect.
- Data collected from a quaternary care children's hospital with a dedicated anticoagulation program.
- Analysis of antithrombin levels, anti-factor Xa activity, and activated partial thromboplastin times pre- and post-antithrombin concentrate administration.
Main Results:
- A single high dose of antithrombin concentrate significantly increased mean antithrombin levels from 0.39 to 1.20 U/mL.
- In cohort 2, post-antithrombin concentrate administration, unfractionated heparin doses were reduced to achieve target anti-factor Xa activity.
- No hemorrhagic, thrombotic, or allergic adverse events were reported within one week of antithrombin concentrate administration.
Conclusions:
- Antithrombin concentrate administration effectively increases anti-factor Xa activity in pediatric patients.
- This allows for a reduction in unfractionated heparin dosage while maintaining therapeutic anticoagulation.
- The study represents the largest evaluation of antithrombin concentrate in children to date, demonstrating a favorable safety profile.
Objective:
To describe antithrombin levels, altered unfractionated heparin effect (anti-factor Xa activity and activated partial thromboplastin time), and adverse effects post administration of a single high dose of antithrombin concentrate.
Design:
Retrospective review.
Patients:
Infants and children with antithrombin levels less than 50% and a subtherapeutic unfractionated heparin effect.
Setting:
Quaternary care children's hospital with a dedicated anticoagulation program.
Interventions:
None.
Measurements And Main Results:
A single high dose of antithrombin concentrate was administered. Antithrombin level, anti-factor Xa, and activated partial thromboplastin times were measured post antithrombin concentrate infusion and daily until stable. One hundred twenty-one patients received 246 doses of antithrombin. Patients were described using two cohorts based on the ability to obtain exact heparin doses. Cohort 1 included all patients between January 2004 and May 2008 when complete heparin dosing was unavailable. Cohort 2 included patients from May 2008 to May 2011 when heparin dose was available. Median age and weight were 3.7 months and 4.1 kg. Mean antithrombin concentrate dose was 222 IU/kg. Mean antithrombin level increased from 0.39 to 1.20 U/mL following antithrombin concentrate administration. In cohort 2, unfractionated heparin doses to achieve a target anti-factor Xa activity pre-post antithrombin concentrate were 28 and 19 U/kg/hr, respectively, for children 12 months old or younger and 25 and 19 U/kg/hr, respectively, for children older than 12 months. There were no hemorrhagic, thrombotic, or allergic events within 1 week of antithrombin concentrate administration.
Conclusions:
This is the largest study of antithrombin concentrate evaluation in children. Administration of antithrombin concentrate increases anti-factor Xa activity with lower administered unfractionated heparin doses.
