Antithrombotic Therapy in Children
Antithrombotic therapy is required for the prevention and treatment of thromboembolic complications in specific pediatric patient populations. Recommendations for antithrombotic therapy in children have been loosely extrapolated from recommendations for adults because thromboembolic events in children were rare enough to hinder testing of specific therapeutic modalities, yet common enough to present significant management dilemmas that required therapeutic intervention.12 However, optimal prevention and treatment of children with thromboembolic complications likely differs from adults because of important ontogenic features of hemostasis that affect both the pathophysiology of the thrombotic processes and the response to antithrombotic agents.
Advances in tertiary care pediatrics have paradoxically resulted in rapidly increasing numbers of children requiring antithrombotic therapy. Intervention trials are now both feasible and urgently needed to provide validated guidelines for antithrombotic therapy in children comments buy tavist online. Since the first publication of this chapter in the 1995 CHEST antithrombotic supplement,23 the authors have become aware of the initiation of five multinational randomized, controlled intervention trials assessing specific aspects of anticoagulant therapy in children. Until the results of these trials are available, modified adult guidelines remain the primary source for recommendations in children.
This chapter is divided into three parts. In the first section, the evidence showing that the interaction of antithrombotic agents with the hemostatic system of the young differs from adults is presented, as are the indications for and the monitoring, therapeutic range, factors influencing dose response relationships, and side effects of antithrombotic agents in children. In the second section, the specific indications for antithrombotic therapy in pediatric patients are discussed. New information available on the use of low-molecular-weight heparin (LMWH) is included. In the third section, the five multinational trials assessing aspects of anticoagulant therapy in children are briefly described. Many of the recommendations are extrapolated from clinical trials in adults and are interpreted within the context of the available information for pediatric patients.
Medline searches of the literature were conducted from 1966 to 1998 using combinations of key words (children, newborns, heparin, warfarin, aspirin, antiplatelet agents, thrombolysis, thrombosis, embolism, mechanical and biological prosthetic heart valves) and supplemented by additional references located through the bibliographies of listed articles. All articles were graded as level 1 to 5. Recommendations were based on strength of study methods (grades A, B, and C) and benefit/risk assessment (grades 1 or 2). Prospective single-arm cohort studies that compared results to the current approach in adults were classified as level IV. Retrospective case series comparing results to the adult literature were classified as level V. Complete reference lists of the level V studies, which constitute the overwhelming majority, are available upon request.