Heparin-Induced Thrombocytopenia Screening and Management in Pediatric Patients

Abstract

The diagnosis and management of heparin-induced thrombocytopenia (HIT) in pediatric patients poses significant challenges. The cardinal findings in HIT, thrombocytopenia and thrombosis with heparin exposure, are seen commonly in critically ill children, but are most often secondary to etiologies other than HIT. However, without prompt diagnosis, discontinuation of heparin, and treatment with an alternative anticoagulant such as a direct thrombin inhibitor (DTI), HIT can result in life-and limb-threatening thrombotic complications. Conversely, DTIs are associated with higher bleeding risks than heparin in adults and their anticoagulant effects are not rapidly reversible; furthermore, the experience with their use in pediatrics is limited. Whereas immunoassays are widely available to aid in diagnosis, they carry a significant false positive rate. Age-dependent differences in the coagulation and immune system may potentially affect manifestations of HIT in children, but have not been extensively examined. In this chapter, diagnostic approaches and management strategies based on a synthesis of the available pediatric studies and adult literature on HIT are discussed.

Pulmonary Embolism due to Heparin-Induced Thrombocytopenia (HIT): A Case Report of an 11-year-old Child Undergoing Scoliosis Surgery and Literature Review

“…Information on the potential benefits and risks of preventive anticoagulation in children is scarce in medical literature. Recommendations regarding thromboprophylaxis in children have been given in some countries (England [2], United States [27,28]) but in France, no consensus exists, hence thromboprophylaxis in children is extrapolated from recommendations for adults [16] and currently mostly administered on an individual basis weighting between thrombotic risks and benefits of anticoagulation for each situation [3]. Eustratiades et al [29] studied thromboprophylaxis for spinal surgery in children.…”

“…HIT development necessitates prior exposure to heparin (flush, heparin-coated catheters, etc.). Therapeutic doses of heparin (versus prophylactic) and intravenous administration (versus subcutaneous) are additional risk factors [16]. The prevalence of HIT-II in adults is known to be much higher in patients receiving UFH (2.6%) compared to those receiving LMWH (0.2%) [17].…”

Małopłytkowość poheparynowa

“…HIT in children is rare [16]; it predominantly regards children with increased risk of thromboembolic complications and affects mostly two age groups [84]. The first group involves preterm infants, newborns requiring intensive care and/or vascular catheters and newborns after cardiac surgery procedures (the incidence of HIT is estimated at approximately 1%).…”

“…The comparison of incidence rates of HIT in individual hospital departments reveals that the syndrome in question was most commonly RRT -renal replacement therapy, DIC -disseminated intravascular clotting, ECMO -extracorporeal membrane oxygenation, IABP -intra-aortic balloon pump, LVAD -left ventricular assist device diagnosed in the departments of cardiac surgery, orthopaedics and trauma (> 3%) followed by general surgery and vascular surgery (> 1%) and gynaecology and obstetrics (~1%); the lowest incidence rate of HIT was observed in non-surgical departments (0.1−1%) [7−9, 14, 15]. Age is not a risk factor; nonetheless, HIT and its consequences are rarely recognised in children [16]. Female patients are at higher risk of HIT, and the clinical symptoms are more pronounced in females [4,5,7,8,14].…”

“…The incidence of venous thrombosis is about fourfold higher compared to arterial thrombosis [4, 5, 7−9, 12, 14, 15] and affects deep limb veins, caval veins, adrenal veins or results in pulmonary embolism [16][17][18]. Arterial thrombosis presents usually with acute limb ischemia (particularly in patients simultaneously receiving vitamin K antagonists), extensive myocardial infarction or cerebral stroke [18−22].…”