Pulmonary hypertension in a seventeen-year-old boy

Transient antiphospholipid syndrome in an infant with segmental small bowel infarction

The clinical picture of venous or arterial thrombosis in the presence of circulating antiphospholipid antibodies is referred to as the antiphospholipid syndrome. A 5-month-old baby girl who was quite healthy so far was referred to our clinic with irritability, vomiting, and abdominal distension for 30 hours. Surgical exploration exposed a gangrenous ileal segment about 15 cm long. The postoperative period was unremarkable. Investigation to identify the risk factors for mesenteric thrombosis found anticardiolipin antibodies (isotype Ig G) and decreased protein C level. Protein S and antithrombin III were within normal levels. Hb electrophoresis results showed no HbS, and neither Factor V Leiden nor prothrombin 20210 mutations were detected. Eight months postoperatively, anticardiolipin antibodies were found within normal levels. Lupus anticoagulant, ds DNA, and ss DNA were negative. Direct coombs test and protein C, C3, and C4 were also within normal levels. She had no thrombotic episode in the 24 months postoperatively, although no anticoagulant medication was administered. To the authors' knowledge this case is the first report of segmental intestinal infarction in transient antiphospholipid syndrome in the pediatric population.

The relationship of antiphospholipid antibodies to thromboembolic events in pediatric patients with systemic lupus erythematosus: a cross-sectional study

The purpose of this study was to evaluate pediatric patients with systemic lupus erythematosus (SLE) to determine 1) the incidence of thrombosis, 2) the incidence of antiphospholipid antibodies, and 3) whether there is an association between the presence of antiphospholipid antibodies and thrombosis. We performed a cross-sectional cohort study in 59 consecutive SLE patients who had been managed at rheumatology clinics in two pediatric hospitals. A history, questionnaire, and chart review were completed by the study nurse blinded to laboratory results. Only the thrombotic events that could be substantiated by review of radiographic tests were accepted. The presence of antiphospholipid antibodies was determined by prospective analysis for a lupus anticoagulant and anticardiolipin antibodies on two separate occasions at least 3 mo apart. Patients were considered to be positive if one or more tests were positive on both occasions. Thirteen thrombotic events occurred in 10 of the 59 patients (17%). Fourteen patients (24%) were classified as positive for lupus anticoagulant, and 19 patients (27%) were classified as positive for anticardiolipin antibodies. A significant relationship between the presence of a lupus anticoagulant and a thrombotic event was shown: odds ratio 28.7 (95% confidence interval 4.03-138.2, p < 0.001). A nonsignificant trend was seen for the presence of an anticardiolipin antibody and a thrombotic event: odds ratio 2.12 (95% confidence interval 0.71-22.8, p=0.08). We conclude that in pediatric patients with SLE: 1) a significant proportion of patients have thrombotic events, 2) a significant proportion of patients have antiphospholipid antibodies, and 3) there is a significant relationship between the presence of a lupus anticoagulant and thrombotic events.

Guidelines for antithrombotic therapy in pediatric patients

Because of the relatively low incidence of TEs in children, the diagnostic and therapeutic approaches used are largely extrapolated from guidelines for adults. Features that differ in children compared with adults include underlying disorders, high incidence of CVL-related DVT in the upper venous system, and response to SH, warfarin, and thrombolytic agents. There is a paucity of information on the risk/benefit ratio of the therapeutic interventions and long-term outcome. Clinical trials are urgently needed to clarify optimal management for pediatric patients with TEs.

Pathophysiology, Diagnosis, and Management of Pulmonary Hypertension in Infants and Children

Pulmonary hypertension (PH) may occur as a primary process or as a complication of several diseases. In the pediatric population, PH secondary to congenital heart disease, chronic hypoxemia, or acute respiratory failure is more common than primary PH. Regardless of etiology, PH may lead to significant morbidity or mortality as a consequence of right-to-left shunting across cardiovascular channels or right heart failure. In this review, PH is defined in terms of the determinants of pulmonary blood flow: pulmonary artery pressure, downstream pressure, and pulmonary vascular resistance. Research addressing both normal developmental changes in pulmonary vascular resistance and abnormal pulmonary vascular reactivity is then reviewed, followed by a discussion of the etiologies of PH in children. Some of the more common clinical presentations of PH are presented focussing on the differences seen between patients with and without intracardiac communications. Assessment of the severity of PH using both noninvasive (electrocardiogram, echocardiogram, magnetic resonance imaging) and invasive (cardiac catheterization, lung biopsy) techniques is then discussed. Treatment of PH is presented, focussing on restoration of adequate pulmonary blood flow through use of both conventional and newer vasodilator therapies. The review concludes by noting the limits to our understanding of the pathogenesis and therapy of PH.

The effect of propofol on normal and increased pulmonary vascular resistance in isolated perfused rabbit lung

The effects of propofol and its intralipid vehicle on increased and normal pulmonary vascular resistances (PVR) were studied in an in situ perfused rabbit lung model which controlled all major determinants of PVR. Propofol at both 5 and 10 micrograms/mL significantly reduced PVR increases by the thromboxane mimetic, U46619. In contrast, similar volumes of intralipid further increased PVR. Neither propofol nor intralipid had any effect on normal PVR. We conclude that propofol at 5 and 10 micrograms/mL is able to reduce increased PVR but has no effect on normal PVR.

Primary antiphospholipid syndrome in a child with lower extremity arterial thrombosis

Primary antiphospholipid syndrome is characterized by venous and arterial thrombosis, fetal loss, or thrombocytopenia in association with antiphospholipid antibodies and no associated disease process. The authors report a case of lower extremity thrombosis in a 12 year old who had primary antiphospholipid syndrome. To our knowledge, this is the first report of peripheral arterial thrombosis in primary antiphospholipid syndrome in the pediatric population.