T he documented cases of thromboembolic disease have risen greatly in the pediatric population, with venous thromboembolism increasing by 70%. 1 Although not completely understood, the growing number of cases is hypothesized to be the result of advances in the treatment of critically ill patients, including the increased use of indwelling catheters. 2-4 Neonates are particularly susceptible to thromboembolic complications. Neonates and adolescents constitute the largest groups of pediatric patients diagnosed with thromboembolic disease, with the rate of venous thromboembolism ranging from 75 to 94 cases per 10,000 hospital admissions, respectively. 1,5,6 The coagulation system is immature at birth, resulting in a unique balance between procoagulants and inhibitors. Healthy neonates are considered hemodynamically stable because most do not develop spontaneous thrombotic complications. 7 The coagulation system may become hypercoagulable in ill neonates with disease states such as respiratory distress, pulmonary hypertension, and sepsis. 3 Because most patients admitted