Successful use of fondaparinux in a child with heparin-induced thrombocytopenia

Thrombosis Prevention and Anticoagulation Management in the Pediatric Patient with Congenital Heart Disease

Thrombosis is one of the most frequent complications affecting children with congenital heart disease (CHD). Palliative and reparative cardiac surgeries are some of the main players contributing to the thrombosis risk in this patient population. Additional risk factors related to the CHD itself (e.g., cardiac dysfunction, arrhythmias, and polycythemia in cyanotic cardiac disorders) can contribute to thrombogenicity alone or combined with other factors. Thrombotic complications have been recognized as a significant cause of morbidity and mortality in this patient population. Here, we provide an overview of the pathophysiology and risk factors for thrombosis as well as the indications for and use of different anticoagulation, antiplatelet, and thrombolytic agents. In addition, we describe some of most common thrombotic complications and their management in the pediatric CHD population.

Coexistence of Antiphospholipid Syndrome and Heparin-Induced Thrombocytopenia in a Patient with Recurrent Venous Thromboembolism

Heparin-induced thrombocytopenia (HIT) is a prothrombotic adverse drug reaction in which heparin forms complexes with platelet factor 4 forming neoantigens that are recognized by autoantibodies. Antiphospholipid syndrome (APS) is similar to HIT in that it is mediated by autoantibodies that are also prothrombotic. We present a case of rare coexistence of antiphospholipid antibody syndrome and heparin-induced thrombocytopenia.

Pediatric Cardiac Intensive Care Society 2014 Consensus Statement: Pharmacotherapies in Cardiac Critical Care Anticoagulation and Thrombolysis

OBJECTIVE

Thrombotic complications are increasingly being recognized as a significant cause of morbidity and mortality in pediatric and congenital heart disease. The objective of this article is to review the medications currently available to prevent and treat such complications.

DATA SOURCES

Online searches were conducted using PubMed.

STUDY SELECTION

Studies were selected for inclusion based on their scientific merit and applicability to the pediatric cardiac population.

DATA EXTRACTION

Pertinent information from each selected study or scientific review was extracted for inclusion.

DATA SYNTHESIS

Four classes of medications were identified as potentially beneficial in this patient group: anticoagulants, antiplatelet agents, thrombolytic agents, and novel oral anticoagulants. Data on each class of medication were synthesized into the follow sections: mechanism of action, pharmacokinetics, dosing, monitoring, reversal, considerations for use, and evidence to support.

CONCLUSIONS

Anticoagulants, antiplatelet agents, and thrombolytic agents are routinely used successfully in the pediatric patient with heart disease for the prevention and treatment of a wide range of thrombotic complications. Although the novel oral anticoagulants have been approved for a limited number of indications in adults, studies on the safety and efficacy of these agents in children are pending.

Fondaparinux in an obese child with heparin-induced thrombocytopenia and a history of renal failure

A 9-year-old obese child with a history of ulcerative colitis was admitted to the intensive care unit for significant blood loss, hemorrhagic shock, and acute renal failure. Following complications from total colectomy secondary to multiple perforations, the patient developed heparin-induced thrombocytopenia (HIT) and subsequent portal vein thrombosis. Subcutaneous (SQ) fondaparinux therapy was initiated because the patient was unable to transition to oral anticoagulation. An anti-factor Xa assay was developed and used to adjust his fondaparinux therapy. Based on hemorrhagic complications and fondaparinux-based anti-factor Xa assay results, the fondaparinux was adjusted to a final dosage of 4.5 mg (0.066 mg/kg) SQ daily. In children unable to transition to oral anticoagulation, fondaparinux may be an alternative for the treatment of thrombosis associated with HIT. We noted that our patient required a lower dose per kilogram of fondaparinux than described in previous published reports. Despite this lower dosage per kilogram, our patient developed bleeding despite dosage reductions; subsequently, a few doses were held. It is unclear if this was related to his obesity, history of renal failure, or a combination of factors. Future studies should determine the optimal dose for special populations of children (e.g., those with obesity and renal failure). Until then, clinicians should routinely monitor and titrate fondaparinux therapy, ideally using a fondaparinux-specific anti-factor Xa assay.