Interhemispheric Differences in Polar Stratospheric HNO3, H2O, CIO, and O3.

Simultaneous global measurements of nitric acid (HNO(3)), water (H(2)O), chlorine monoxide (CIO), and ozone (O(3)) in the stratosphere have been obtained over complete annual cycles in both hemispheres by the Microwave Limb Sounder on the Upper Atmosphere Research Satellite. A sizeable decrease in gas-phase HNO(3) was evident in the lower stratospheric vortex over Antarctica by early June 1992, followed by a significant reduction in gas-phase H(2)O after mid-July. By mid-August, near the time of peak CIO, abundances of gas-phase HNO(3) and H(2)O were extremely low. The concentrations of HNO(3) and H(2)O over Antarctica remained depressed into November, well after temperatures in the lower stratosphere had risen above the evaporation threshold for polar stratospheric clouds, implying that denitrification and dehydration had occurred. No large decreases in either gas-phase HNO(3) or H(2)O were observed in the 1992-1993 Arctic winter vortex. Although CIO was enhanced over the Arctic as it was over the Antarctic, Arctic O(3) depletion was substantially smaller than that over Antarctica. A major factor currently limiting the formation of an Arctic ozone "hole" is the lack of denitrification in the northern polar vortex, but future cooling of the lower stratosphere could lead to more intense denitrification and consequently larger losses of Arctic ozone.

Nonnutritive sucking during gavage feeding enhances growth and maturation in premature infants.

The effects of nonnutritive sucking (NNS) by means of a pacifier during gavage feeding were studied in 30 premature infants whose birth weight was less than 1,500 g. The addition of NNS accelerated the maturation of the sucking reflex, facilitating a more rapid transition from gavage to oral feedings. Additionally, NNS decreased intestinal transit time and caused a more rapid weight gain despite comparable caloric intake resulting in a shortened hospital stay. Although the physiologic mechanisms resulting from this form of oral stimulation remain to be investigated, our data suggest that NNS may be an important factor to consider in the feeding of premature infants.

The therapeutic application of end-expiratory pressure in the meconium aspiration syndrome.

The effectiveness of end-expiratory pressure (EEP) in relieving hypoxemia in the meconium aspiration syndrome (MAS) was studied in 14 patients with the disorder. These infants demonstrated a direct, mean PO2 response of 12 torr/cm H2O EEP. A maximum PO2 response was observed in an EEP range of 4 to 7 cm H2O. EEP was equally effective whether patients were breathing spontaneously or were being mechanically ventilated. EEP is useful in the treatment of hypoxemia in the infants with meconium aspiration syndrome.

Maternal rating of child health at school age: does the vulnerable child syndrome persist?

OBJECTIVES: To assess the extent to which parental ratings of child health, including perceived vulnerability to illness, are associated with current and past health events and sociodemographic characteristics of the family and the child. DESIGN: Prospective cohort study of children aged 8 to 10 years previously assessed in infancy in two multi-site studies. SETTING: Thirteen sites largely in eastern United States. PARTICIPANTS: 1877 children representing 65% of those originally selected for follow-up from the two previous studies. Participants were specifically selected on the basis of birth weight so that more than two-thirds were low birth weight. MEASUREMENT: Parental interviews at school age including measures of several dimensions of child health and sociodemographic characteristics of the family. The former included a six-item scale assessing parental perceptions of child health overall, and on subscales assessing child current health, previous health, and resistance or susceptibility to illness. Data on health problems at birth were derived from previously collected birth certificates, medical records, and interviews. MAIN RESULTS: Although overall parental perceptions of child health reflected both current and past health events, a clear distinction emerged. Parental rating of current child health and resistance or susceptibility were associated with current child health problems, not events in infancy including very low birth weight. Nonwhite race and maternal rating of her own health also influenced maternal rating of child health. CONCLUSION: The results do not support the persistence of a vulnerable child syndrome, as health in infancy does not affect maternal rating of current child health at school-age in the absence of current health problems.

Pulmonary hypertension in the perinatal aspiration syndromes.

Ten patients clinically diagnosed as having perinatal aspiration syndromes were found to have pulmonary hypertension. These infants were either term or postmature babies and had the following characteristics: (1) systemic or suprasystemic levels of pulmonary artery pressure (range, 50 to 117 mm Hg); (2) a degree of pulmonary hypertension not related to the degree of aspiration evident on chest roentgenograms; (3) evidence of right-to-left shunting at the ductal or foramen ovale level; and (4) sustained severe hypoxemia despite 100% inspired oxygen concentration. The overall mortality for the group was 50%. Since these patients had marked clinical and physiologic similarities to patients previously reported as having the persistent fetal circulation syndrome (PFC), they were classified as having "PFC with aspiration." The existence of pulmonary hypertension should be suspected despite roentgenographic evidence of aspiration in any patient who also manifests the clinical characteristics of PFC because its treatment may alter the prognosis of such patients.

Retrolental fibroplasia and blood transfusion in very low-birth-weight infants.

The relative contribution of transfusions of adult blood to the development of retrolental fibroplasia (RLF) in very low-birth-weight infants was examined. Five years of experience with the expanded use of replacement and exchange transfusions in 90 infants with birth weight less than or equal to 1,250 gm was reviewed. Twenty percent of the infants developed cicatricial RLF. Exchange transfusion was not related to development of cicatricial RLF. The incidence of RLF in infants receiving greater or equal to 130 ml of packed red blood cells per kilogram of birth weight as replacement blood transfusion (RBT) was significantly higher (42.9%) than that in infants receiving 61 to 131 ml of packed red blood cells per kilogram (15.4%) and infants receiving less than or equal to 60 ml of packed red blood cells per kilogram (0%), P less than .001. The need for RBT, however, was strongly correlated (r = .85, P less than .001) with increasing duration of O2 therapy. When O2 therapy was controlled for, the association between RBT and RLF did not achieve statistical significance (P = .07). The association between RBT and RLF remained significant when adjusted for duration of therapy in fractional inspired oxygen (FIO2) greater than 0.4. Further detailed studies of large numbers of susceptible infants are warranted to assess the magnitude of the contribution of transfusions of adult blood to development of RLF.

Relationship of prolonged pharmacologic serum levels of vitamin E to incidence of sepsis and necrotizing enterocolitis in infants with birth weight 1,500 grams or less.

The incidence of culture-proven neonatal sepsis and necrotizing enterocolitis (NEC) in preterm infants maintained at pharmacologic (mean 5.1 mg/dL +/- 1.45 SD) serum vitamin E levels for long periods was prospectively studied as part of a double-masked clinical trial of the effect of prophylactic vitamin E v placebo treatment on the development and course of retinopathy of prematurity (ROP). Within a few days of birth, 914 preterm infants were enrolled in the study; 545 (275 placebo-treated infants, 270 vitamin E-treated infants had birth weight of 1,500 g or less. A significant difference in incidence of neonatal sepsis (17 placebo-treated infants, 37 vitamin E-treated infants) and NEC (18 placebo-treated infants, 32 vitamin E-treated infants) was observed among infants who had been treated for eight or more days and who had developed neither sepsis nor NEC before that time. The association of vitamin E treatment with increased incidence of disease was much higher with sepsis than with NEC. The most likely reason for these observations is a pharmacologic serum vitamin E-related decrease in oxygen-dependent intracellular killing ability which results in a decreased resistance to infection in preterm infants. The data suggest that, if this occurs, it is clinically significant only in the more immature infants. In view of the known variability of absorption of oral vitamin E and the association between high serum vitamin E levels and increased incidence of sepsis and late-onset NEC reported here, it can be concluded that serum vitamin E levels must be monitored when supplemental vitamin E is administered to premature infants, especially those with birth weight 1,500 g or less. The risk-benefit ratio of long-term treatment using vitamin E at high serum levels should be clearly assessed.

Evaluation of the preterm infant for patent ductus arteriosus.

As a first step in a multicenter, collaborative project to study the role of indomethacin in the management of patent ductus arteriosus in premature infants, a diagnostic scheme was developed, on an a priori basis, by a consensus of the participating neonatologists and pediatric cardiologists. The scheme, which utilizes clinical and noninvasive findings, was designed to detect infants with a "hemodynamically significant" patent ductus arteriosus (PDA). Among 1,689 infants with birth weight less than 1,750 g who were monitored during the first year of the study, 342 (20.2%) met the criteria for PDA. Rates were higher for smaller infants (42% with birth weight less than 1,000 g) than for larger infants (7% with birth weight 1,500 to 1,750 g). Although study protocol did not require a direct procedure to confirm the diagnosis of PDA, a marked decrease in the presence of most criteria was noted following surgical ligation of the ductus. Although the echocardiographic criterion (ratio of left atrium to aorta [LA/Ao] greater than or equal to 1.15) proved to have a low specificity for PDA, the data suggest that the overall scheme led to a very low rate of false-positive diagnosis. Following the application of the scheme for 1 year at 13 clinical centers, it has been shown to be a highly acceptable means of detecting infants with PDA.

Fibrinogen degradation products in acute renal failure of the newborn.

Acute parenchymal renal failure (ARF) in the newborn infant has emerged as a major problem since the advent of neonatal intensive care units. Because intravascular and/or intrarenal coagulation may be important in the development of ARF, a prospective study of coagulation was performed on 20 babies with ARF, with particular emphasis on the measurement of fibrinogen degradation products (FDP) in serum and urine. Thirteen babies with respiratory distress syndrome (RDS) and 40 healthy neonates served as controls. Initial serum FDP levels were significantly higher in ARF than in RDS or normals (P less than 0.001); initial urine FDP levels were higher in ARF than in normals (P less than 0.01). Levels of FDP did not differentiate among the various etiologies of ARF. Since initial urine FDP levels are high in normal newborns, serial urine FDP were compared among patient groups and found to be highest in ARF. Initial serum and urine FDP levels could not differentiate among the 11 survivors and 9 nonsurvivors, but FDP levels declined as the duration of ARF (e.g., survival) increased, often antedating the recovery of renal function. We conclude: (1) serum and urine FDP are significantly elevated in most newborns with ARF; (2) factors other than hypoxia may be involved in the pathogenesis of elevated serum FDP in RDS with ARF newborns, indicating the importance of coagulation; (3) serial measurements of serum and urine FDP may be early indicators of recovery of renal function.

When you're only a phone call away: a comparison of the information in telephone and face-to-face interviews.

Telephone interviews offer an economical method of obtaining information, but little published experience addresses the use of telephone interviews for the sometimes lengthy questionnaires composed of scales with multiple-category items often required in developmental and behavioral research. In a study of the outcomes of very low birth weight infants, circumstances required that we administer a questionnaire, including seven scales composed of several Likert-type items each, to a substantial portion of the study population. Those contacted by telephone (n = 1067) differed from those responding face-to-face (n = 822) in being less likely to have a very low birth weight child and more likely to be white and of higher maternal education. The length of the interview was only slightly shorter by telephone (60.7 +/- 27.9 vs 66.4 +/- 21.0 minutes, p < .001), but respondent fatigue, as indicated by lower completion rates for scales at the end of the interview (92.5%) compared with those near the beginning (99.5%) did not differ by mode. Internal consistency of parental response (Cronbach's alpha) was high for most scales and did not differ by mode. Because assignment to mode was not random, other factors may influence our findings. However, high completion rates and comparable consistency of response supports the use of telephone interviews.

Maternal cocaine abuse and necrotizing enterocolitis: outcome and survival.

Since 1987, multiple complications related to maternal cocaine abuse have been reported. Necrotizing enterocolitis-(NEC) of the newborn has been observed with increasing frequency. We report a comparative analysis of infants with NEC born to cocaine abusing mothers (n = 11) to a standard population of newborns with NEC (n = 50) treated in this institution from January 1987 to July 1989. We also evaluated whether prenatal cocaine abuse predisposes infants to NEC by performing a case-control analysis using 51 of 61 infants and controls matched for race, sex, and birthweight +/- 250g. Significant differences were apparent between the cocaine-affected infants (COC) and the noncocaine-affected infants (Non-COC) with regard to surgical intervention (72.7% v 38%, P less than .05), the presence of massive gangrene (54% v 12%, P less than .01), mortality (54.5% v 18%, P less than .01), and maternal age (28.13 +/- 3.82 years v 24.12 +/- 6.21 years P less than .05). No differences between these groups could be demonstrated for other known NEC risk factors such as gestational age, birthweight, feeding patterns, umbilical artery catheters, or asphyxia. In the matched case-control study, infants born to mothers who were cocaine abusers demonstrated a 2.5-fold increased risk of developing NEC (95% Cl = 1.17 to 5.32, P = .02) when compared with the noncocaine-exposed group. Maternal cocaine abuse appears to play a contributory role in the pathogenesis of NEC, its extent, and its outcome.

A clinical score for predicting the level of respiratory care in infants with respiratory distress syndrome.

A scoring system was developed to predict the need for transferring infants with respiratory distress syndrome (RDS) from community hospitals to specialized respiratory care centers. Five clinical and laboratory determinations (birthweight, clinical RDS score, FI02, PCO2 and pH) recorded from 100 infants with RDS during one year were utilized in a score with values ranging from 0 to 10. Application of the score to 159 infants with RDS during the following year showed that: (1) 73 per cent of infants scoring less than or equal to 3 received only oxygen by hood; (2) 75 per cent of infants scoring 4--5 required continuous positive airway pressure (CPAP); and (3) 87 per cent of infants scoring greater than or equal to 6 needed mechanical ventilation (7V). Mean scores were significantly different (p less than 0.02) for each type of respiratory therapy employed: oxygen by hood (2.30 +/- 0.19 S.E.M.); CPAP (4.27 +/- 0.16 S.E.M.); MV (6.72 +/- 0.25 S.E.M.). The accuracy and simplicity of the score make it valuable for the physician in the community hospital to assist in deciding when to transfer a neonate with RDS for more intensive respiratory therapy.

The clinical profile of the newborn with persistent pulmonary hypertension. Observations in 19 affected neonates.

In 19 neonates with severe cyanosis, normal chest x-rays, anatomically normal hearts, and a high incidence of perinatal complications, the clinical course was characterized by variable sustained cyanosis. Cardiac catheterization data showed high systemic or suprasystemic pulmonary artery pressure with right to left intracardiac shunting via the foramen ovale and ductus arteriosus. Arterial oxygen tension at an inspired oxygen concentration above 65% was helpful in distinguishing these patients from those with congenital heart disease, and for predicting prognosis.

Physiologic factors affecting pulmonary artery pressure in infants with persistent pulmonary hypertension.

Indwelling pulmonary artery catheters were used for continuous monitoring of pulmonary artery pressure in ten infants with severe persistent pulmonary hypertention of the newborn. The labile nature of pulmonary artery pressure, with changes up to 50 mm Hg, was documented. Pulmonary artery pressure in the eight infants with suprasystemic pulmonary hypertension was analyzed at the time of maximum decrease in pressure (mean 36.1 mm Hg) and physiologic measurements were compared over an eight-hour period. During the study period when the infants were hyperventilated, as the Paco2 decreased from 48.9 to 28.3 mm Hg (P less than 0.02) the mean pulmonary artery pressure decreased by 36 mm Hg (P less than 0.001) to subsystemic pressure levels, and the mean AadeltaO2 decreased by 146 mm Hg (P less than 0.001). After the decrease in pulmonary artery pressure, patients were mechanically ventilated to maintain Paco2 in the range of 25 to 30 mm Hg until pulmonary hypertension gradually resolved in the six survivors.

Beckwith-Wiedemann syndrome with unusual hepatic and pancreatic features: a case expanding the phenotype.

We describe an infant with Beckwith-Wiedemann syndrome (BWS) who had hepatic and pancreatic findings not previously described in BWS. These were biliary dysgenesis and enlargement and cystic dysplasia of the pancreas. The biliary dysgenesis was characterized by proliferation of abnormally shaped ducts in the portal tracts. Massive enlargement and cystic dysplasia of the pancreas was associated with ductular proliferation, virtual absence of normal exocrine tissue, and an increase in endocrine tissue.

The health and developmental status of very low-birth-weight children at school age.

OBJECTIVE: To assess the effect of improved survival of increasingly premature infants by examining the outcomes at school age of a large group of children born at different birth weights. DESIGN: Inception cohort. SETTING/PARTICIPANTS: Participants were selected from two previously studied multisite cohorts: very low-birth-weight (less than or equal to 1500 g) children referred to participating intensive care units and heavier birth-weight children drawn from a stratified random sample of births in geographically defined regions. Follow-up at 8 to 10 years of age was by a combination of telephone interview and home/clinic visits for 65.1% (1868) of those eligible. MAIN OUTCOME MEASURES: The presence or absence of 17 specific conditions, limitations in activities of daily living due to health, mental health (affective health, behavior problems), and, for a subset, IQ scores. RESULTS: Decreasing birth weight was associated with an increased morbidity for all measures except affective health; those with birth weights of 1500 g or less were more likely to experience multiple health problems. Maternal educational attainment did not influence the association of birth weight with morbidity except for IQ among children whose birth weight was above 1000 g, for which socioeconomic disadvantage worsened the status of all children irrespective of birth weight. CONCLUSIONS: Children born at lower birth weights experience increased morbidity at early school age. These results reinforce the importance of postdischarge, early intervention programs to reduce the risk of these later health problems.

Hospitalization of very low birth weight children at school age.

OBJECTIVE: To assess whether very low birth weight (VLBW) increases the risk of hospitalization at school age. DESIGN: Prospective, multisite cohort study. PARTICIPANTS: Selected from a previous multisite, hospital-based trial, 611 VLBW children, and, from a prior representative sample, 724 children who weighed 1501 to 2500 gm and 533 who weighed > 2500 gm. All the children were re-contacted at 8 to 10 years of age for this study. METHODS: Maternal interview with the use of standardized questions. MAIN OUTCOME: Hospitalization in year before interview. RESULTS: The VLBW children were three or four times more likely to be rehospitalized than children of normal birth weight, both in the year before the interview (7% vs 2%) and since birth (50% to 60% vs 22%). Morbidity and Medicaid coverage increased the risk of hospitalization in the year before the interview; non-white race decreased it. After control for other factors, however, lower birth weight remained a significant risk factor for hospitalization. CONCLUSIONS: The VLBW children continue to have an increased risk of hospitalization; the risk is similar in magnitude to that seen in infancy.