Cardiorespiratory function in asymptomatic survivors of neonatal respiratory distress syndrome.

We measured cardiopulmonary function at rest and during exercise in 15 healthy survivors of neonatal respiratory distress syndrome (RDS) and compared the results with those in 15 normal subjects. The mean birth weight of the RDS group was 1,771 g, and 12 of the 15 patients had required endotracheal intubation. The oxygen scores ranged from 79 to 3,322. Five of the 15 RDS patients had abnormal results of pulmonary function studies at rest. Peak expiratory flow was lower (P less than 0.05) in the RDS group (2.98 liters/min) than in the control group (3.57 liters/min). A negative correlation was noted between the forced expiratory flow between 25 and 75% of vital capacity and the oxygen score in these patients. Exercise tolerance was below normal in two of the RDS patients, both of whom also had abnormal pulmonary function at rest. One patient in the RDS group had systemic arterial hypertension at rest and during exercise. No significant differences in exercise tolerance or the cardiorespiratory response to exercise were observed between the two groups.

Effects of drugs and chemicals on the fetus and newborn (2).

Physicians have become increasingly aware of the side effects of specific drugs. Obstetricians and family physicians should especially be cognizant of the implications of the administration of any drug, not only for the pregnant mother but also for the unborn child. In this second installment of our two-part article, we conclude our review of drugs, chemicals, and environmental pollutants that may affect the fetus or newborn.

Effects of drugs and chemicals on the fetus and newborn (1).

Drug teratogenicity has been demonstrated experimentally for more than 30 years. After the discovery of the thalidomide-induced embryopathies, the fetal dangers of maternal drug ingestion were overemphasized. Accumulation of additional information during the past 15 years has led to a more balanced viewpoint concerning drug teratogenicity. A complex set of circumstances must prevail for a specific teratogenic effect to result. Not only the drug or environmental pollutant in question but also its dose, timing, and frequency of administration as well as the genetic and individual susceptibility of the embryo are important factors. Herein we review the currently available information on drug and environmental effects on the fetus and neonate.

Treatment of defects of the anterior abdominal wall in newborns.

Primary closure of an omphalocele or gastroschisis may cause respiratory compromise in the neonate. Some authors recommend primary closure of the defect with prolonged respiratory support because of dissatisfaction with staged visceral reduction and use of a Silastic pouch. Our experience with use of a Silastic pouch from 1975 to 1982 was reviewed. Twenty-three newborns with major defects of the abdominal wall (14 omphaloceles and 9 gastroschisis anomalies) were surgically treated, and only one death occurred. The mean birth weight of the infants was 2,927 g; nine of them were premature. Seven infants had major associated anomalies. The goal of the surgical procedure was closure of the abdominal wall without compromise of the cardiorespiratory status. During the operation, muscle relaxants were avoided and the infants breathed spontaneously. If progressive visceral reduction caused tachypnea (rate of more than 70/min) or hemodynamic instability, a Silastic pouch was constructed. Ten patients were treated with primary fascial closure, and 13 were treated with a Silastic prosthesis. The neonates with the prostheses required three to eight reductions, and the prostheses were in place for 4 to 22 days. No patient had wound dehiscence, wound infection, or an intestinal fistula. The one death occurred in an infant with trisomy 18 syndrome and multiple anomalies. Thus, the Silastic pouch was effective when the defect could not be closed primarily without respiratory compromise.

Prognostic value of brainstem auditory evoked potentials in neonates.

The clinical outcome in 74 children at risk for audiologic or neurologic sequelae of a variety of perinatal insults was correlated with brainstem auditory evoked potentials (BAEPs) in the newborn period. No constant relationship was found between BAEP findings and later hearing status in preterm infants or in infants with severe brain damage. However, persistent patterns of wave I abnormality correctly predicted the presence and type of hearing loss in other infants. Central BAEP abnormalities recorded in preterm infants or in infants who had just suffered anoxia had little predictive value. The abnormalities had greater prognostic value when there was a delay between acute injury and testing. Prognostic errors could be minimized in this population by obtaining repeated recordings at least one month post term and after injury from infants who showed BAEP abnormalities in the neonatal period.

Serum levels of creatine phosphokinase and its isoenzymes in normal and stressed neonates.

Twenty-six normal newborns (13 male, 13 female) with normal prenatal histories, no perinatal stress, and normal vaginal deliveries had creatine phosphokinase (CPK) activity and isoenzyme activities assayed in cord blood and in 24-hour postpartum serum. Total CPK activity was high in cord blood when compared with adult control values. Moreover, the total CPK was significantly higher in serum at 24 hours of age compared with cord blood. There was a significant increase in both the skeletal muscle isoenzyme and the cardiac muscle isoenzyme from birth to 24 hours of age. There was a decrease in the brain isoenzyme at 24 hours of age which was not statistically significant. These results were compared with values obtained in a group of 10 neonates with severe cardiac problems. Three of the ill neonates had significant elevation of total serum CPK and the skeletal muscle isoenzyme when compared with the normal newborns. There were no significant differences between the normal infants and the ill neonates for the cardiac isoenzyme and the brain isoenzyme. These data suggest that caution should be used in the diagnosis of certain neonatal cardiac syndromes based on serum CPK levels and isoenzyme alone.

Gastrointestinal mucormycoses in infants and children: a cause of gangrenous intestinal cellulitis and perforation.

Gastrointestinal mucormycosis has been a uniformly fatal disease in children. Diagnosis has been difficult, resulting in inadequate therapy. Histologic and bacteriologic confirmation of invasive infection, followed by systemically administered amphotericin B and surgical excision, are the hallmarks of effective treatment.

False-positive rubella hemagglutination-inhibition (HAI) titers in neonates and children with conjugated hyperbilirubinemia.

Two neonates, one with extrahepatic biliary atresia and one with cystic fibrosis, and a 9-year-old child with atresia of the common bile duct had conjugated hyperbilirubinemia and elevated rubella HAI titers when kaolin pretreatment of serum was used. A beta-lipoprotein fraction of the serum that is frequently found in association with biliary obstruction was shown to be the probable source of the rubella HAI inhibitor. This beta-lipoprotein was not removed by standard kaolin treatment of serum, but was removed almost completely by dextran sulfate--calcium chloride treatment. In the presence of conjugated hyperbilirubinemia, routine kaolin pretreatment of serum is an inadequate measure for the removal of interfering substances, as false-positive rubella HAI results are obtained consistently.

Intraventricular hemorrhages in full-term and premature infants.

Intraventricular hemorrhages were the most common neuropathologic findings in both full-term and premature infants in a retrospective study of neonatal deaths. In general, the intraventricular hemorrhages of full-term infants were less frequent, originated from veins of the choroid plexus, were small, and rarely caused death. Intraventricular hemorrhages of premature infants usually originated in the germinal matrix and were large enough to be fatal. Intraventricular hemorrhages were most frequently found when death occurred between 24 and 72 hours of age.

Use of tolazoline in newborn infants with diaphragmatic hernia and severe cardiopulmonary disease. A preliminary report.

Two newborn infants with congenital diaphragmatic hernia, one of whom died, had significant improvement in arterial oxygen tension (Pao2) after intravenous administration of tolazoline (Priscoline) (1 to 2 mg. per kilogram). In both infants, systemic hypotension developed within minutes of administration of the drug and required pharmacologic and hemodynamic intervention. The response to tolazoline was more dramatic in the infant who survived, and his oxygen requirements were significantly reduced after the use of this drug. The infant who died also had a significant response to tolazoline. Tolazoline appears to be an important pharmacologic agent for use in the postoperative care of infants with diaphragmatic hernia and associated hypoxemia and acidosis.

Erythrocyte catechol-0-methyltransferase and plasma dopamine-beta-hydroxylase in human umbilical cord blood.

Plasma dopamine-beta-hydroxylase enzymatic activity and immunoreactive protein levels in human umbilical cord blood are only about 2% as great as values in the blood of older subjects. Erythrocyte catechol-0-methyltransferase activity levels in umbilical cord blood are very similar to those in the blood of adult subjects.

False aneurysm of the descending aorta: a complication of umbilical artery catheterization.

A patient had an aneurysm of the descending aorta secondary to aortitis arising from umbilical artery catheterization and in association with coarctation of the aorta. The aortitis probably was the direct result of bacterial contamination of the umbillicus and catheter with Staphylococcus aureus and the placement of the catheter tip just distal to a coarctation of the aorta. The patient required surgical resection of the coarctation and aneurysm of the descending aorta and placement of a tubular Dacron graft at 6 month of age. This is, to our knowledge, a hitherto unreported complication of umbilical artery catheterization.

The effect of time of cord clamping and maternal blood pressure on placental transfusion with cesarean section.

We measured the residual placental blood volume (RPBV) of 20 infants delivered at term by cesarean section of women not in labor. In all cases, the umbilical cord was clamped within 40 seconds of birth. RPBV decreased significantly with increasing age at cord clamping. In addition, RPBV for infants with cords clamped within 20 seconds of birth correlated inversely with maternal systolic blood pressure (mean RPBV = 54.8 ml. per kilogram at 105 torr and 28.4 ml. per kilogram at 148 torr). However, RPBV did not correlate with maternal blood pressure for the whole group of 20 infants or for those with cords clamped later than 20 seconds after birth. These data indicated that in infants delivered by cesarean section placental transfusion is time related during the first 40 seconds of life and that maternal blood pressure also influences the magnitude of placental transfusion during the first 20 seconds after birth. Analysis of data from this study combined with data from a previous study shows that after 40 seconds the net flow between placenta and infant reverses and that cord clamping delayed beyond this point is accompanied by a rise in RPBV back to the level found when the cord was clamped before 20 seconds.

Inclusion blennorrhea: a case report.

The case described here represents the first laboratory-confirmed case of inclusion blennorrhea at the Mayo Clinic since laboratory isolation of Chlamydia trachomatis was instituted in 1974. Treatment with a sulfonamide preparation proved effective. Further aspects of the diagnosis and treatment of inclusion blennorrhea are discussed.