Given the number of centers involved and the size of the database, we feel that our results broadly reflect current practice in the use of HFOV in pediatric patients. These results may help in deciding which patients are most likely to benefit from aggressive intervention by using extracorporeal techniques and may help identify high-risk populations appropriate for prospective study of innovative modes of supporting gas exchange (e.g., partial liquid breathing or intratracheal pulmonary ventilation).

The results of this preliminary investigation were unexpected but important in view of the increased use of probiotic preparations in medically fragile pediatric patients. In this randomized, placebo-controlled trial, L. rhamnosus strain GG was not shown to be effective in reducing the incidence of nosocomial infections. In fact, a statistically nonsignificant trend toward an increase in infection was seen (four vs. 11). Further studies with a larger patient population are needed to establish both safety and efficacy of probiotics in pediatric critical care.

Between May 1984 and April 1993, 59 children underwent balloon angioplasty of a native coarctation at our institution. The follow-up protocol included a cardiac catheterization 1 to 2 years after angioplasty, which was performed in 90% of patients with > or = 2 years follow-up. Angioplasty caused an acute decrease in peak systolic gradient from 46 +/- 2 to 15 +/- 2 mm Hg, without early aneurysm or emergent surgical intervention in any patient. Based on follow-up data, a satisfactory result was obtained in 38 patients (64%; 70% confidence limit: 58% to 71%), defined as a residual systolic gradient < 20 mm Hg and no aneurysm. In these patients the gradient decreased acutely from 43 +/- 2 to 9 +/- 1 mm Hg, was 6 +/- 1 mm Hg at follow-up catheterization, and 9 +/- 2 mm Hg by clinical evaluation 4.4 +/- 0.3 years after angioplasty. Twenty-one patients (36%; 70% confidence limit: 29% to 42%) had an unsatisfactory result due to a residual gradient > or = 20 mm Hg (n = 19) or aneurysm formation (n = 3), or both. Restenosis occurred in 6 patients, and occurred more in infants than in children > or = 12 months of age (3 of 5 infants vs 3 of 41 children, p = 0.01). Thus, balloon angioplasty provides an effective initial treatment strategy for native coarctation in most children aged > 12 months.

No abstract

We evaluated safety and feasibility of the transvenous limb perfusion gene delivery method in muscular dystrophy. A dose escalation study of single limb perfusion with 0.9% saline starting with 5% of limb volume was carried out in adults with muscular dystrophies under intravenous analgesia/anesthesia. Cardiac, vascular, renal, muscle, and nerve functions were monitored. A tourniquet was placed above the knee with inflated pressure of 310 mm Hg. Infusion was carried out with a clinically approved infuser via an intravenous catheter inserted in the saphenous vein with a goal infusion rate of 80 ml/minute. Infusion volume was escalated stepwise to 20% limb volume in seven subjects. No subject complained of any post procedure pain other than due to needle punctures. Safety warning boundaries were exceeded only for transient depression of limb tissue oximetry and transient elevation of muscle compartment pressures; these were not associated with nerve, muscle, or vascular damage. Muscle magnetic resonant imaging (MRI) demonstrated fluid accumulation in muscles of the perfused lower extremity. High-pressure retrograde transvenous limb perfusion with saline up to 20% of limb volume at above infusion parameters is safe and feasible in adult human muscular dystrophy. This study will serve as a basis for future gene transfer clinical trials.

No abstract

To better understand the clinical presentation and surgical management of children with aortic arch complex anomalies ("vascular rings"), a retrospective study was performed on patients who presented to Children's National Medical Center between the years 1969 and 1989. A total of 59 patients were identified ranging in age at admission from birth to 14 years, of whom 35 (59%) were male and 24 (41%) female. Patients were classified into four major subtypes based on their surgical anatomy, with 29 (49%) patients having right aortic arch and left ductus/ligamentum arteriosus, 21 (36%) double aortic arch, 6 (10%) anomalous left pulmonary artery, and 3 (5%) arch artery anomaly (no ring); 19 patients (32%) had associated cardiac defects. The mean (+/-SD) age at onset of symptoms was 4.6 +/- 14.0 months, and the age at surgical repair was 18 +/- 34 months. There were no intraoperative mortalities, but two late deaths occurred. Three (5%) patients had a surgical complication. In contrast to previous studies, the incidence of nonring lesions was lower and associated cardiac defects higher. Forty-nine percent of patients had symptoms present at birth, and patients with associated cardiac disease did not present earlier than those without. In patients with right aortic arch and left ductus/ligamentum arteriosus, few had an anomalous left subclavian artery. Finally, equal dominance of the arches was most frequent in patients with double aortic arch. Aortic arch complex anomalies present symptomatically in a variety of ways, and noninvasive methods are used to identify the specific lesion and associated cardiac defects. Surgical repair is associated with low or no mortality in patients with uncomplicated aortic arch complex anomalies.

The objective of this investigation was to compare how two modes of positive pressure ventilation affect cardiac output, airway pressures, oxygenation, and carbon dioxide removal in children with congenital heart disease in the immediate postoperative period. The investigation used a one group pretest-post-test study design and was performed in the pediatric cardiac intensive care unit in a university-affiliated children's hospital. Nine infants were enrolled immediately after repair of tetralogy of Fallot (2) or atrioventricular septal defects (7) with mean weight = 5.5 kg (4.2-7.3 kg). Children were admitted to the pediatric cardiothoracic intensive care unit after complete surgical repair of their cardiac defect and stabilized on a Siemen's Servo 300 ventilator in volume control mode (VCV1) (volume-targeted ventilation with a square flow wave pattern). Tidal volume was set at 15 cc/kg (total). Hemodynamic parameters, airway pressures and ventilator settings, and an arterial blood gas were measured. Patients were then changed to pressure-regulated volume control mode (PRVC) (volume-targeted ventilation with decelerating flow wave pattern) with the tidal volume set as before. Measurements were repeated after 30 minutes. Patients were then returned to volume control mode (VCV2) and final measurements made after 30 minutes. The measurements and results are as follows: After correction of congenital heart defects in infants, mechanical ventilation using a decelerating flow wave pattern resulted in a 19% decrease in peak inspiratory pressure without affecting hemodynamics, arterial oxygenation, or carbon dioxide removal.