Decision-making in the delivery room: a survey of neonatologists.

OBJECTIVE: To examine influences on neonatologists' decision-making regarding resuscitation of extremely premature infants. STUDY DESIGN: A mailed survey of Illinois neonatologists evaluated influences on resuscitation. Personal and parentally opposed (that is, acting against parental wishes) gray zones of resuscitation were defined, with the lower limit (LL) the gestational age at or below which resuscitation would be consistently withheld and the upper limit (UL) above which resuscitation was mandatory. RESULT: Among the 85 respondents, LL and UL of the personal and parentally opposed gray zones were median 22 and 25 weeks, respectively. Neonatologists with an UL personal gray zone <25 completed weeks were significantly more fearful of litigation, more likely to have received didactic/continuing medical education teaching, and less likely to always consider parents' opinions in resuscitation decisions. Neonatologists with an UL parentally opposed gray zone <25 completed weeks were more fearful of litigation. CONCLUSION: Neonatologists perceive a 'gray zone' of resuscitative practices and should understand that external influences may affect their delivery room resuscitation practices.

Respiratory instability of term and near-term healthy newborn infants in car safety seats.

OBJECTIVE: Premature infants who are discharged from intensive care nurseries are known to be at increased risk for apnea, bradycardia, and oxygen desaturation while in the upright position. These small infants also do not fit securely in standard infant car seats. Because of these problems, the American Academy of Pediatrics recommends a period of observation in a car seat for all infants who are born at <37 weeks' gestation. It is not clear whether this recommendation should apply to the minimally preterm infants (born at 35-36 weeks' gestation) who are healthy at birth and are hospitalized in the normal newborn nursery. The objective of this study was to evaluate the respiratory stability and safety requirements of healthy, minimally preterm infants in car seats compared with term infants. METHODS: Fifty healthy, nonmonitored, preterm infants (mean gestational age: 35.8 +/- 0.6 weeks) and 50 term infants (mean gestational age: 39.5 +/- 1.4 weeks) were recruited from a level I newborn nursery in a community hospital. Appropriateness of car seat fit was documented for each infant. Heart rate, respiratory rate, and pulse oximetry were evaluated while infants were supine and in their car seats. Apneic and bradycardic events were recorded in addition to a continuous recording of oxygen saturation values. RESULTS: Twenty-four percent of preterm and 4% of term newborn infants did not fit securely into suitable car seats despite the use of blanket rolls. Mean oxygen saturation values declined significantly in both preterm and term infants from 97% in the supine position (range: 92%-100%) to 94% after 60 minutes in their car seats (range: 87%-100%). Seven infants (3 preterm and 4 term) had oxygen saturation values of <90% for longer than 20 minutes in their car seats. Twelve percent of the preterm infants (95% confidence interval: 4.5%-24.3%) but no term infants had apneic or bradycardic events in their car seats. CONCLUSIONS: Our data support the current American Academy of Pediatrics recommendations that all infants who are born at <37 weeks' gestation, including those who are admitted to level I community hospitals, be observed for respiratory instability and secure fit in their car seats before hospital discharge. Because lowering of oxygen saturation values was seen uniformly in all newborn infants, car seats should be used only for travel, and travel should be minimized during the first months of life.

Neurophysiologic evaluation of auditory recognition memory in healthy newborn infants and infants of diabetic mothers.

OBJECTIVES: We evaluated the integrity of neural pathways for auditory recognition memory in normal newborn infants (n = 32) and infants of diabetic mothers (IDMs, n = 25). IDMs are at risk for fetal metabolic abnormalities that potentially damage recognition memory pathways. We hypothesized that newborn IDMs would have recognition memory deficits that would be correlated with later cognitive development. STUDY DESIGN: Recognition memory was assessed with event-related potentials (ERPs). Neonatal ERPs elicited by the maternal voice were compared with those elicited by a stranger's voice. The Bayley Scales of Infant Development were administered at 1 year of age. RESULTS: Infants in both the control and IDM groups demonstrated recognition of the maternal voice, but their ERP patterns differed. Both groups demonstrated increased amplitude and latency for the "P2" peak elicited by the maternal voice compared with the stranger's voice. In the control group the stranger's voice also elicited a negative slow wave, which was attenuated in the IDMs. The negative slow wave correlated significantly with the 1-year Mental Developmental Index. CONCLUSIONS: The presence of a specific neonatal ERP pattern indicated better 1-year cognitive development in infants in the control and IDM groups. ERPs from IDMs demonstrated subtle evidence of recognition memory impairments.

Randomized, controlled trial of low-dose inhaled nitric oxide in the treatment of term and near-term infants with respiratory failure and pulmonary hypertension.

UNLABELLED: Recent reports indicate that inhaled nitric oxide (iNO) causes selective pulmonary vasodilation, increases arterial oxygen tension, and may decrease the use of extracorporeal membrane oxygenation (ECMO) in infants with persistent pulmonary hypertension of the newborn (PPHN). Despite these reports, the optimal dose and timing of iNO administration in PPHN remains unclear. OBJECTIVES: To test the hypotheses that in PPHN 1) iNO at 2 parts per million (ppm) is effective at acutely increasing oxygenation as measured by oxygenation index (OI); 2) early use of 2 ppm of iNO is more effective than control (0 ppm) in preventing clinical deterioration and need for iNO at 20 ppm; and 3) for those infants who fail the initial treatment protocol (0 or 2 ppm) iNO at 20 ppm is effective at acutely decreasing OI. STUDY DESIGN: A randomized, controlled trial of iNO in 3 nurseries in a single metropolitan area. Thirty-eight children, average gestational age of 37.3 weeks and average age <1 day were enrolled. Thirty-five of 38 infants had echocardiographic evidence of pulmonary hypertension. On enrollment, median OI in the control group, iNO at 0 ppm, (n = 23) was 33.1, compared with 36.9 in the 2-ppm iNO group (n = 15). RESULTS: Initial treatment with iNO at 2 ppm for an average of 1 hour was not associated with a significant decrease in OI. Twenty of 23 (87%) control patients and 14 of 15 (92%) of the low-dose iNO group demonstrated clinical deterioration and were treated with iNO at 20 ppm. In the control group, treatment with iNO at 20 ppm decreased the median OI from 42.6 to 23.8, whereas in the 2-ppm iNO group with a change in iNO from 2 to 20 ppm, the median OI did not change (42.6 to 42.0). Five of 15 patients in the low-dose nitric oxide group required ECMO and 2 died, compared with 7 of 23 requiring ECMO and 5 deaths in the control group. CONCLUSION: In infants with PPHN, iNO 1): at 2 ppm does not acutely improve oxygenation or prevent clinical deterioration, but does attenuate the rate of clinical deterioration; and 2) at 20 ppm acutely improves oxygenation in infants initially treated with 0 ppm, but not in infants previously treated with iNO at 2 ppm. Initial treatment with a subtherapeutic dose of iNO may diminish the clinical response to 20 ppm of iNO and have adverse clinical sequelae.

Chronic physiologic instability is associated with neurodevelopmental morbidity at one and two years in extremely premature infants.

OBJECTIVE: The objective of this study was to evaluate the relationships between chronic physiologic instability, as assessed by the cumulative daily Score for Neonatal Acute Physiology (SNAP), and neurodevelopmental morbidity in premature infants at 1 year and at 2 to 3 years of age. DESIGN: The subjects of this retrospective study were extremely premature (75th percentile). MDI, PDI, and REEL scores were compared for the three groups using analysis of variance. To evaluate the relative contributions of physiologic stability, intracranial abnormalities, GA, and early postnatal nutritional intakes, multiple regression analyses were performed using cumulative SNAP score, an intraventricular hemorrhage (IVH) score (incorporating IVH and periventricular leukomalacia), GA, and a weight-change score for the first month as independent variables, and MDI, PDI, and REEL quotients as dependent variables. Regression analyses were repeated, with cumulative SNAP subscores for oxygenation, hypotension, acidosis, and hypoxia/ischemia included with IVH score, GA, and first month weight z score change as independent variables, and MDI, PDI, and REEL quotients as dependent variables. RESULTS: The infants with the highest degree of physiologic instability (cumulative SNAP scores greater than the 75th percentile) had significantly lower MDI scores at 1 year of age and lower PDI scores at 1 year and at 2 to 3 years of age than did infants who were more physiologically stable. Sixty-seven percent of infants with cumulative SNAP scores greater than the 75th percentile had neurodevelopmental abnormalities at 2 to 3 years of age (cerebral palsy or delayed mental, motor, or language development). Using multiple regression analyses, higher cumulative SNAP scores, IVH scores, and GA were associated with lower 1-year MDI scores. Higher cumulative SNAP scores and IVH scores were associated with lower 1-year PDI scores. By 2 years, only higher cumulative SNAP scores were significantly associated with lower MDI and PDI scores. With respect to language development, only lower weight-change scores over the first month were significantly associated with poorer receptive language development. Lower weight-change scores over the first month and higher hypotension scores were significantly associated with poorer expressive language development. In the secondary regression analyses, higher IVH score, higher cumulative oxygenation scores, and higher hypoxia/ischemia scores all were significantly associated with lower 1-year MDI scores. By 2 to 3 years of age, only higher oxygenation scores were significantly associated with lower MDI scores. CONCLUSIONS: Prolonged physiologic instability was associated with deleterious neurodevelopmental consequences for extremely premature infants through 2 to 3 years of age, independent of effects of intracranial abnormalities and GA.

Association between the severity of chronic lung disease and first-year outcomes of very low birth weight infants.

OBJECTIVE: The objective of this study was to determine if there is an association between the severity of chronic lung disease in very low birth weight infants (as assessed by the duration of supplemental oxygen requirements in the neonatal period) and first-year neurodevelopmental, sensory, and growth outcomes as well as duration of neonatal hospitalization and first-year hospital readmissions. STUDY DESIGN: Retrospective chart review with matched subject groups. METHODS: The subjects of this study were very low birth weight infants born between 1987 and 1991 in a 17-county perinatal region of North Carolina. Infants were categorized into one of three groups on the basis of duration of supplemental oxygen requirements. Infants who were breathing room air by 28 days were classified as having no chronic lung disease; infants who required supplemental oxygen at 28 days but not at 36 weeks postmenstrual age were classified as having mild chronic lung disease; and infants who required supplemental oxygen at 36 weeks postmenstrual age were classified as having severe chronic lung disease. Infants were matched for birth weight, sex, and race. The matched groups (n = 174) were compared with respect to the incidence of first year adverse neurodevelopmental and sensory outcomes, growth patterns, and hospital readmissions during the first year. Results were analyzed with general linear models and logistic regression analyses. RESULTS: The incidence of any adverse neurodevelopmental or sensory outcome increased as severity of chronic lung disease increased from none (3.6%) to mild (21.4%) to severe (31.6%, p < 0.001). Growth patterns were similar in infants with no and mild chronic lung disease, but infants with severe chronic lung disease were significantly lighter (p < 0.01) and shorter (p < 0.005) at 40 weeks postmenstrual age and significantly lighter at 1 year adjusted age (p < 0.05). The duration of the initial hospitalization increased with chronic lung disease severity (p < 0.001). Infants with severe chronic lung disease were readmitted to the hospital significantly more often (p < 0.005) than infants with no chronic lung disease or mild chronic lung disease. CONCLUSIONS: Very low birth weight infants who required supplemental oxygen at or beyond 28 days were at increased risk for adverse neurodevelopmental and sensory outcomes, but only those infants who continued to require supplemental oxygen at 36 weeks were at increased risk for poor growth and readmission to the hospital.

Visual event-related brain potentials in 4-month-old infants at risk for neurodevelopmental impairments.

The recording of event-related potentials (ERPs) is an electrophysiologic technique that has been used to evaluate the functional maturation of neural pathways responsible for recognition memory systems in infants and children. The purpose of this study was to evaluate ERP correlates of visual recognition memory in 4-month-old infants at risk for later cognitive impairments. We compared ERPs using a test of shape recognition at 4 months of age (adjusted for prematurity) in 16 high-risk, neonatal intensive care unit (NICU) survivors and 16 healthy full-term infants. ERPs were recorded while infants were familiarized with one stimulus (a red cross, 15 trials), then tested with 60 trials of this familiar stimulus and a novel stimulus (a red corkscrew). Both the NICU and control groups' ERPs demonstrated evidence of differential processing of the two stimuli, but the NICU groups' ERP patterns were distinctly different from those of the control group. In the NICU group, the novel stimulus elicited parietal positivity at 1000-1700 ms poststimulus, whereas in the control group the novel stimulus elicited occipital and frontal negativity at 500-1700 ms poststimulus. The ERP pattern demonstrated by the NICU group was atypical as it has not been previously described in healthy infants. The results of the study indicate that the ERP technique can be used to demonstrate altered patterns of neural activity during tasks of visual recognition memory in high-risk infants. We speculate that the atypical ERP patterns described in this study may indicate that patterns of synaptic organization were altered by neonatal events.

Outcome at 4 to 5 years of age in children recovered from neonatal chronic lung disease.

Outcomes were compared for 31 very-low-birthweight children recovered from chronic lung disease and 31 very-low-birthweight controls. All children had been free of major abnormalities on neonatal cranial ultrasonography. At 4 to 5 years of age, children were examined by a pediatrician and tested by a psychologist who administered the Wechsler Preschool and Primary Scale of Intelligence-Revised. Despite similar medical outcomes, the children who had had neonatal chronic lung disease had lower Full-scale IQs (median 83 vs 87) and Performance IQs (79 vs 90). Median Verbal IQ was similar in the two groups (85 vs 87). A higher proportion of children who had had chronic lung disease had Full-scale IQ < 70 (8/31 [26%] vs 1/31 [3%]) and Performance IQ < 70 (8/31 [26%] vs 0/31). These effects persisted after adjustment for confounding factors.

Growth failure and altered body composition are established by one month of age in infants with bronchopulmonary dysplasia.

Long-term growth failure and altered body composition are common consequences of bronchopulmonary dysplasia (BPD). We hypothesized that these chronic findings are preceded by uncompensated, acute early growth failure. The purpose of this study was to evaluate the effects of developing bronchopulmonary dysplasia on body composition and growth of very-low-birth-weight (VLBW) infants during the first six postnatal weeks. Arm muscle and fat accretion and changes in weight, length and head circumference were evaluated in 16 very-low-birth-weight infants who developed bronchopulmonary dysplasia and compared with 16 birth-weight-matched control infants without bronchopulmonary dysplasia. During the 1st wk, both groups experienced similarly low nutritional intakes, wasting of arm muscle and fat stores, and reduced weight, length and head circumference growth velocities, compared with intrauterine growth standards. Between wk 2 and 4, infants with developing bronchopulmonary dysplasia consumed less protein and energy (P < 0.05), accreted less arm fat and muscle (P < 0.05), and grew more slowly than control infants in all measured variables (P < 0.05). When infants with bronchopulmonary dysplasia had achieved full enteral feedings and had similar protein-energy intakes to control infants, they demonstrated similar rates of growth and arm muscle and fat accretion, but did not demonstrate catch-up growth. These data support the speculation that early reductions in muscle and fat accretion and growth velocity contribute to the long-term growth failure in infants with bronchopulmonary dysplasia. Prevention may require greater attention to defining and delivering optimal nutritional therapy to physiologically unstable premature infants in the immediate postnatal period.