Abnormalities of the lymphatic circulation are well recognized in patients with congenital heart defects. However, it is not known how the associated abnormal blood flow patterns, such as increased pulmonary blood flow (PBF), might affect pulmonary lymphatic function and structure. Using well-established ovine models of acute and chronic increases in PBF, we cannulated the efferent lymphatic duct of the caudal mediastinal node and collected and analyzed lymph effluent from the lungs of lambs with acutely increased PBF ( n = 6), chronically increased PBF ( n = 6), and age-matched normal lambs ( n = 8). When normalized to PBF, we found that lymph flow was unchanged following acute increases in PBF but decreased following chronic increases in PBF. The lymph:plasma protein ratio decreased with both acute and chronic increases in PBF. Lymph bioavailable nitric oxide increased following acute increases in PBF but decreased following chronic increases in PBF. In addition, we found perturbations in the transit kinetics of contrast material through the pleural lymphatics of lambs with chronic increases in PBF. Finally, there were structural changes in the pulmonary lymphatic system in lambs with chronic increases in PBF: lymphatics from these lambs were larger and more dilated, and there were alterations in the expression of vascular endothelial growth factor-C, lymphatic vessel endothelial hyaluronan receptor-1, and Angiopoietin-2, proteins known to be important for lymphatic growth, development, and remodeling. Taken together these data suggest that chronic increases in PBF lead to both functional and structural aberrations of lung lymphatics. These findings have important therapeutic implications that warrant further study.

Hemolytic uremic syndrome (HUS) can be classified as typical and atypical, and the treatment recommendations currently differ between the 2 types. Eculizumab is recommended as first-line treatment for atypical HUS; however, its use in typical HUS has been controversial. We report a case of a 10-year-old male with severe neurologic impairment who was successfully treated with eculizumab, which was started 4 days after onset of neurologic symptoms. Our case supports the use of eculizumab in typical HUS with neurologic involvement, even when given later in the course, as the pathophysiology of typical HUS has been shown to involve activation of the complement pathway, similar to atypical HUS. Further studies are required to establish the efficacy and duration of eculizumab use in this patient population.

Central pontine myelinolysis (CPM) is rarely reported in pediatric patients with diabetic ketoacidosis (DKA). We report this case of a 16-year-old female with new onset diabetes presenting with DKA, who received aggressive fluid resuscitation and sodium bicarbonate in the emergency department. Later she developed altered mental status concerning for cerebral edema and received hyperosmolar therapy with only transient improvement. Soon she became apneic requiring emergent endotracheal intubation. MRI brain showed cerebral edema, CPM, and subdural hemorrhage. She was extubated on day seven and exhibited mild dysmetria, ataxia, unilateral weakness, and neglect. Upon discharge she was able to ambulate with a walker and speak and eat without difficulty. Although less common than cerebral edema, CPM should be considered in DKA patients with acute neurologic deterioration. Fluid and bicarbonate therapy should be individualized, but larger studies would help guide the management. Although poor outcomes are reported in CPM, favorable outcomes are possible.

Acute rheumatic fever (ARF) is an acute inflammatory process resulting in rheumatic carditis, one of the most common acquired heart diseases in youth. Among the clinical manifestations of carditis, pathologic valve regurgitation and atrioventricular block are included in the criteria for the diagnosis of ARF. Besides atrioventricular block, ARF may often present with other arrhythmias, such as junctional tachycardia (JT). However, JT is currently not recognized as a criterion for the diagnosis of ARF. Three adolescents presented in our hospital with JT, polyarthralgia, and laboratory signs of inflammation with evidence of preceding group A Streptococcus infection. None of the patients fulfilled the diagnostic criteria of ARF. On the basis of the presumed diagnosis of ARF, all 3 patients were treated with intravenous steroids. Steroid therapy was given, and JT converted to sinus rhythm within an average of 62 hours. Subsequent electrocardiograms revealed variable degree of atrioventricular block in all 3 patients, providing clinical evidence and fulfilling the diagnostic criteria of ARF. Patients were monitored for a total 2 to 8 days before discharge on standard antiinflammatory treatment. Follow-up electrocardiograms and Holter monitoring revealed resolution of the atrioventricular block and lack of JT recurrence in all patients. On the basis of these sentinel cases, we propose that JT should be included as a diagnostic criterion for the diagnosis of ARF.

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