Paul T. Pitlick

Late Pulmonary Sequelae of Bronchopulmonary Dysplasia

BACKGROUND Bronchopulmonary dysplasia is a chronic lung disease that often develops after mechanical ventilation in prematurely born infants with respiratory failure. It has become the most common form of chronic lung disease in infants in the United States. The long-term outcome for infants with bronchopulmonary dysplasia has not been determined. METHODS We studied the pulmonary function of 26 adolescents and young adults, born between 1964 and 1973, who had bronchopulmonary dysplasia in infancy. We compared the results with those in two control groups: 26 age-matched adolescents and young adults of similar birth weight and gestational age who had not undergone mechanical ventilation, and 53 age-matched normal subjects. RESULTS Sixty-eight percent of the subjects with bronchopulmonary dysplasia in infancy (17 of the 25 tested) had airway obstruction, including decreases in forced expiratory volume in one second, forced expiratory flow between 25 and 75 percent of vital capacity, and maximal expiratory flow velocity at 50 percent of vital capacity, as compared with both control groups (P less than 0.0001 for all comparisons). Twenty-four percent of the subjects with bronchopulmonary dysplasia in infancy had fixed airway obstruction, and 52 percent had reactive airway disease, as indicated by their responses to the administration of methacholine or a bronchodilator. Hyperinflation (an increased ratio of residual volume to total lung capacity) was more frequent in the subjects with a history of bronchopulmonary dysplasia than in either the matched cohort (P less than 0.0006) or the normal controls (P less than 0.0004). Six of the subjects who had bronchopulmonary dysplasia in infancy had severe pulmonary dysfunction or current symptoms of respiratory difficulty. CONCLUSIONS Most adolescents and young adults who had bronchopulmonary dysplasia in infancy have some degree of pulmonary dysfunction, consisting of airway obstruction, airway hyperreactivity, and hyperinflation. The clinical consequences of this dysfunction are not known.

Pharmacologic Closure of Patent Ductus Arteriosus in the Premature Infant

The prostaglandins affect smooth-muscle tone of the ductus arteriosus. Patent ductus often complicates the clinical course of prematurely born infants with respiratory-distress syndrome. In the present study, a single oral or rectal dose of a potent inhibitor of prostaglandin synthesis, indomethacin, was administered to six consecutive premature infants with the syndrome who would otherwise have undergone surgical ligation of the patent ductus. Within 24 hours all the clinical symptoms and physical, echocardiographic and radiographic signs attributable to substantial left-to-right shunting through a patent ductus arteriosus dramatically and permanently disappeared. A transient reduction in renal function was observed in two infants in whom sustained ill-effects did not occur. The observation that constriction and closure of the patent ductus arteriosus may be induced pharmacologically raises important possibilities for the improved treatment of the respiratory-distress syndrome.

Phrenic Nerve Injury Complicating Closed Cardiovascular Surgical Procedures for Congenital Heart Disease

Phrenic nerve injury (PNI) with resulting hemidiaphragmatic paralysis occurred in 19 (2.1 +/- 0.5%) of 891 closed cardiac surgical procedures during a twenty-three-year period. Diagnosis was confirmed by standard radiographic criteria. Phrenic nerve injury was most commonly noted following systemic-pulmonary artery anastomosis, ligation of persistent ductus arteriosus plus pulmonary artery banding, and atrial septectomy. Most patients were managed conservatively (nasotracheal or orotracheal intubation and positive end-expiratory pressure). Although no deaths were a direct result of PNI, major complications occurred in 15 of the 19 instances of PNI (79% +/- 10%). The serious morbidity and the hospital costs associated with this complication, however, underscore the cardinal importance of prevention. If injury does occur, early surgical intervention (diaphragmatic plication) in very young infants may reduce the attendant morbidity, but the complete role of diaphragmatic plication remains to be defined.

Cardiac localization of transvascular bioptome using 2-dimensional echocardiography

Two-dimensional (2-D) echocardiography was added to standard fluoroscopic localization of transvascular endomyocardial biopsy in 7 children with heart muscle disease whose ages were 6 months to 18 years. One left ventricular and 11 right ventricular biopsies were carried ot without complications using the fluoroscopic-echocardiographic technique. Two-dimensional echocardiographic monitoring has the advantages of reducing radiation exposure and providing anatomic information about intracardiac structures as well as bioptome localization. Lateral beam spread and reverberation artifacts represent potential problems with 2-D echocardiography, but they did not cause significant difficulties in this study.

Renal responses of the fetal lamb to fetal or maternal volume expansion.

Fetal and maternal glomerular filtration rate (GFR), renal plasma flow (RPF), urine volume, sodium excretion, and fractional sodium reabsorption were measured in a chronically instrumented sheep preparation. Fetal GFR was essentially stable between 110 and 135 days of gestation (term = 147 days). There was a significant increase in GFR after 135 days. After the infusion of 50 ml of normal saline over a 30-minute period, fetal GFR and sodium excretion increased significantly. Fractional sodium reabsorption was significantly decreased. Thus, the fetus is capable of responding to volume expansion with saline with an increase in GFR and a decrease in fractional sodium reabsorption. After the infusion of 1000 ml of normal saline into the ewe in 1 hour, maternal GFR and RPF rose significantly. Sodium excretion rose 6-fold and fractional sodium reabsorption fell significantly. After the infusion of saline into the ewe, there was no change in fetal GFR, RPF, sodium excretion, urine volume, or fractional sodium reabsorption. Since there were no changes in fetal renal function after maternal volume expansion with saline there was no evidence for the transplacental passage of a natriuretic factor from ewe to fetus.

Alveolar capillary dysplasia: Diagnostic potential for cardiac catheterization

OBJECTIVE:Alveolar capillary dysplasia is a rare cause of persistent pulmonary hypertension of the newborn. Infants with this condition die despite maximal medical intervention including inhaled nitric oxide therapy and extracorporeal membrane oxygenation. To date, diagnosis of this lethal condition was made by open lung biopsy or during postmortem examination. We examined the possibility that distinct cardiac catheterization findings could be used in the diagnosis of this lethal disorder.STUDY DESIGN:We present three infants with fatal persistent pulmonary hypertension of the newborn refractory to extracorporeal membrane oxygenation and inhaled nitric oxide therapy, two with postmortem autopsy confirmation of alveolar capillary dysplasia. Each infant underwent cardiac catheterization to complete the diagnostic evaluations.RESULTS:Significant right ventricular hypertension and normal pulmonary venous return were demonstrated, but a markedly diminished or absent capillary blush phase was noted in each infant. This finding is distinct from the normal capillary blush seen in infants with persistent pulmonary hypertension of the newborn of other etiologies.CONCLUSION: Cardiac catheterization may provide a useful alternative to tissue examination in the diagnosis of alveolar capillary dysplasia.

Successful pregnancy after the mustard operation for transposition of the great arteries

Abstract Recent advances have dramatically increased survival rates of infants born with complete transposition of the great arteries. Quality of life is also important as these patients mature, and a major consideration for a woman is her ability to have a baby. Such was the case with the patient described herein.

Transcutaneous PO2 monitoring in infants with cyanotic congenital heart disease treated with prostaglandin E1.

SummaryTranscutaneous PO2 (tcPO2) has been shown to closely approximate arterial PO2 (PaO2) in infants with normal oxygenation (PaO2 60–100 mm Hg). During hypoxemia (PaO2<60 mm Hg), or administration of vasoactive drugs, such as tolazoline, correlation is frequently so poor that tcPO2 monitoring is of little value. We examined the relationship of tcPO2 to PaO2 among 6 infants with cyanotic congenital heart disease who were receiving prostaglandin E1 (PGE1). Close, linear correlation was found, even during hypoxemia. We conclude that tcPO2 monitoring has potential clinical value in such patients.

Results of intraventricular baffle procedure for ventricular septal defect and double outlet right ventricle or d-transposition of the great arteries.

Thirty patients with ventricular septal defect and d-transposition of the great arteries or double outlet right ventricle underwent placement of an intraventricular baffle to achieve physiologic correction. Eighteen of these patients also required an external conduit to establish continuity between the right ventricle and the pulmonary artery. There was an overall 22 percent early mortality rate, although the rate was 63 percent in patients who weighed less than 10 kg. There was an additional 20 percent late mortality rate, primarily related to conduction disturbances and pulmonary vascular obstructive disease, problems that have not occurred in patients operated on since 1974. Of the survivors, all are asymptomatic and as a group have achieved a significant weight gain. Many have residual hemodynamic abnormalities that required cardiac catheterization for precise assessment. Four patients have been reoperated on, with no additional mortality.

Three-Dimensional Visualization of Recurrent Coarctation of the Aorta by Electron-Beam Tomography and MRI

The patient was a 12-year-old boy who was born with a coarctation of the thoracic aorta. He underwent a Gore-Tex patch angioplasty of the coarctation at 13 days of age. Subsequent restenosis led to subclavian flap angioplasty at age 7 months. He presented now with upper extremity hypertension and decreased femoral pulses. Attempted visualization of the aortic isthmus by cross-sectional echocardiography was inadequate. The family was initially reluctant to consent to a cardiac catheterization. After 3-dimensional (3D) reconstruction of electron-beam tomography (EBT) and MRI (Figures 1⇓ and 2⇓), the pathological condition was more fully appreciated. The patient then underwent cardiac …