Clinical trial of tin mesoporphyrin to prevent neonatal hyperbilirubinemia

OBJECTIVE

To assess the efficacy of the heme oxygenase inhibitor, tin mesoporphyrin (SnMP), to reduce total bilirubin (TB) levels.

STUDY DESIGN

Masked, SnMP (4.5 mg kg(-1)), placebo-controlled, multicenter trial of single intramuscular injection to newborns ⩾35 weeks gestational age whose predischarge screening transcutaneous bilirubin (TcB) was >75th percentile.

RESULTS

Two hundred and thirteen newborns (median age 30 h) were randomized to treatment with SnMP (n=87) or 'sham' (n=89). We found that the duration of phototherapy was halved. Within 12 h of SnMP administration, the natural TB trajectory was reversed. At age 3 to 5 days, TB in the SnMP-treated group was +8% but sixfold lower than the 47% increase in the sham-treated group (P<0.001). At age 7 to 10 days, mean TB declined 18% (P<0.001) compared with a 7.1% increase among controls. No short-term adverse events from SnMP treatment were noted other than photoreactivity due to inadvertent exposure to white light phototherapy.

CONCLUSION

Early, predischarge SnMP administration decreased the duration of phototherapy, reversed TB trajectory and reduced the severity of subsequent hyperbilirubinemia.

Effect of storage on breast milk antioxidant activity

BACKGROUND

Human milk, which contains compounds beneficial to infants, is often expressed and stored before use. Changes in its antioxidant activity with storage have not been studied.

OBJECTIVES

To measure antioxidant activity of fresh, refrigerated (4 degrees C), and frozen human milk (-20 degrees C), stored for two to seven days; to compare the antioxidant activity of milk from mothers delivering prematurely and at term; to compare the antioxidant activity of infant formulas and human milk.

METHODS

Sixteen breast milk samples (term and preterm) were collected from mothers within 24 hours of delivery and divided into aliquots. Fresh samples were immediately tested for antioxidant activity, and the rest of the aliquots were stored at -20 degrees C or 4 degrees C to be analysed at 48 hours and seven days respectively. The assay used measures the ability of milk samples to inhibit the oxidation of 2,2'-azino-di-3-(ethylbenzthiazolinesulphonate) to its radical cation compared with Trolox.

RESULTS

Antioxidant activity at both refrigeration and freezing temperatures was significantly decreased. Freezing resulted in a greater decrease than refrigeration, and storage for seven days resulted in lower antioxidant activity than storage for 48 hours. There was no difference in milk from mothers who delivered prematurely or at term. Significantly lower antioxidant activity was noted in formula milk than in fresh human milk.

CONCLUSIONS

To preserve the antioxidant activity of human milk, storage time should be limited to 48 hours. Refrigeration is better than freezing and thawing.

Urinary thiobarbituric acid-reacting substances as potential biomarkers of intrauterine hypoxia

BACKGROUND

Currently available clinical tools cannot accurately identify the extent of perinatal hypoxic injuries. During hypoxia, reactive oxygen species cause lipid peroxidation of cell membranes, yielding oxidation products that constitute thiobarbituric acid-reacting substances (TBARS).

OBJECTIVE

To see if the concentrations of TBARS excreted in urine would be elevated during the first day of life in term and preterm infants following chronic hypoxia or acute asphyxia.

DESIGN

Thiobarbituric acid-reacting substances levels were measured by a spectrophotometric assay in urine samples collected from term and near-term (>/= 34 weeks gestation, n = 22), and preterm (<34 weeks gestation, n = 52) infants on the first day of life.

PATIENTS

Infants were admitted to the St Peter's University Hospital (New Brunswick, NJ) neonatal intensive care unit from July 1997 to January 1999. Acute asphyxia was defined as umbilical cord blood pH values less than 7.05, or Apgar scores of less than 5 at 5 minutes. Chronic hypoxia was defined as intrauterine growth retardation or low birth weight (small for gestational age) associated with pregnancy-induced hypertension or reversal of umbilical arterial blood flow.

RESULTS

Among term infants, urinary TBARS levels were significantly increased following acute asphyxia (P =.02). Levels of TBARS also tended to be elevated following chronic hypoxia. Urinary TBARS levels in term infants tended to be increased in those requiring mechanical ventilation (P =.05) or delivery room resuscitation (P =.15), as well as in those passing intrauterine meconium (P =.13) or having clinical evidence of hypoxic-ischemic encephalopathy (P =.24).

CONCLUSIONS

The results show a correlation between elevated urinary TBARS levels in term and near-term infants, and perinatal hypoxia (as determined by low Apgar scores or umbilical cord blood acidosis). We speculate that TBARS concentrations may be useful as a biomarker for perinatal hypoxic injury in newborns. Further studies are needed to determine whether elevations in TBARS levels are better predictors of the extent of hypoxic injury than existing markers.

Parental compliance with home cardiorespiratory monitoring

AIMS

To evaluate parental compliance with home cardiorespiratory monitoring of premature infants with apnoea, siblings of infants who died of sudden infant death syndrome (SIDS), and infants with an apparent life threatening event (ALTE), during the first month of use.

METHODS

A retrospective review of the first month's recordings was conducted on 39 premature infants with apnoea, 13 siblings of SIDS, and 16 infants with ALTE. All infants were singletons. Recommendations during the study period (1992-1994) were for daily use for 23 hours per day. Measurements were average daily hours of use and consistency of use (daily or variable). Gestational age, maternal age, and socioeconomic status as measured by receipt of public assistance were also recorded.

RESULTS

Siblings of SIDS were monitored for fewer hours than were premature or ALTE infants. Only 54% of sibings of SIDS were monitored daily, compared to 87% of premature infants and 93% of ALTEs. Within each diagnostic category socioeconomic status did not affect average hours of monitoring. Consistency of use was more evident in those with private insurance, although the trend did not reach significance.

CONCLUSIONS

Parents of infants with apnoea of prematurity or ALTE are highly compliant with cardiorespiratory monitoring recommendations in the first month of monitor usage. Siblings of SIDS are monitored for fewer hours and are less likely to be monitored on a daily basis.

Effects of perinatal hypoxia on serum unbound free fatty acids and lung inflammatory mediators

Cellular injury during tissue hypoxia is due, in part, to reactive intermediates released by activated leukocytes. We found that the inflammatory mediators tumor necrosis factor (TNF)-alpha, IL-6, and IL-1beta are elevated in situ in lung macrophages on day 14 following exposure of rats to intermittent or chronic hypoxia from birth. Because inflammatory mediators can increase lipolysis in adipocytes, we also measured serum unbound free fatty acids (FFAu)--the biologically active compartment of FFA--in rat pups exposed to intermittent or chronic hypoxia. FFAu values were markedly elevated during the first 2 days of life in all rats, displaying an approximately 3-fold decrease from day 2 to day 3. Exposure to chronic hypoxia significantly increased FFAu levels measured on day 13. Since elevated serum FFAu are known to suppress leukocyte activation, we speculate that increased FFAu levels represent a mechanism for attenuating inflammation and tissue injury following sublethal hypoxia in the perinatal period, either physiologically in the immediate newborn period, or as a late response to ongoing hypoxic insult.

Maternal behavior toward premature twins: implications for development

Assisted reproductive techniques and fertility enhancing therapies have increased multiple births and, therefore, the risk of prematurity and its developmental consequences. Parent intervention is an effective source of compensation for the cognitive effects of prematurity. We hypothesized that relative to parents of preterm singletons, parents of preterm twins are less able to provide such enhancing care, resulting in a developmental disadvantage for preterm twins. Maternal-infant interactions of premature singletons (n = 22; birth weight = 1668 +/- 350 g, gestational age = 32.3 +/- 2.1 weeks) and premature twins (n = 8; birth weight = 1618 +/- 249 g; gestational age = 32.0 +/- 2.6 weeks) with comparable demographic and medical status were observed at home at 1 and 8 months corrected age using a 30 min checklist of developmentally facilitative behavior. Mental (MDI) and psychomotor (PDI) indices of the Bayley Scales of Infant Development and Caldwell Home Observations for Measurement of the Environment (HOME) inventories were administered (18 months corrected age). Compared with mothers of premature singletons, mothers of premature twins exhibited fewer initiatives (P < 0.001) and responses (P < 0.01) and were less responsive to positive signals (P < 0.01) and crying (P < 0.01). Unprompted by the infant, twin mothers lifted or held (P < 0.05), touched (P < 0.01), patted (P < 0.05) or talked (P < 0.01) less. Singleton MDIs surpassed twins (119.4 +/- 7.7 vs 103.6 +/- 7.7; P < 0.01). Maternal verbal behavior and the acceptance of child factor (HOME), both favoring singletons, correlated with MDI (R-square = 0.46, P < 0.0002). Mothers of premature twins exhibited fewer initiatives and responses toward offspring than did mothers of premature singletons. Maternal behavior was predictive of cognitive development.

Topographic mapping of brain potentials in the newborn infant: the establishment of normal values and utility in assessing infants with neurological injury

AIM

To demonstrate that quantitative EEG (qEEG) can be used as a non-invasive measure of brain injury by establishing normative data in term infants and contrasting it with other modalities of brain imaging.

DESIGN

qEEG during quiet sleep was performed on 13 healthy full-term infants comprising a normal group and on 10 infants with neurological abnormalities identified on brain imaging studies (abnormal group) at 36-47 wk postconceptional age. Quantitative analysis was performed and topographic maps were produced for each patient. The EEG data from the normal group, after spectral analysis, yielded power data in the delta, theta, alpha, and beta frequency bands and coherence information, which then formed the normative database. qEEG from the infants in the abnormal group was then compared to this normative data.

RESULTS

The normal group's mean absolute power in the delta, theta, alpha, and beta bands for all EEG leads combined were 278.48+/-83.83, 31.71+/-10.12, 29.20+/-2.04, and 35.76+/-11.35 uv2, respectively. The median frequency was 1.49+/-0.07, 5.45+/-3.46, 9.74+/-5.11, and 18.01+/-3.38 Hz, respectively. The qEEG was abnormal in all 10 study infants, while abnormalities were noted in the clinical EEG in 4 of 10, in the neuroultrasound in 5 of 10, in the CT in one of 6, and in the MRI in 2 of 2 tested.

CONCLUSIONS

qEEG appears to be a useful non-invasive method for measuring brain injury as it correlates well with other modalities of brain imaging and, if corroborated by further study, may, in fact, be more sensitive in determining abnormalities in brain function.

A multicenter long-term safety and efficacy trial of preterm formula supplemented with long-chain polyunsaturated fatty acids

BACKGROUND

The tissue accretion of long-chain polyunsaturated fatty acids is compromised in infants born prematurely. Human milk contains long-chain polyunsaturated fatty acids, but most preterm infant formulas do not. The long-term effects of preterm formula supplemented with arachidonic acid and docosahexaenoic acid, in proportions typical of those in human milk, were therefore investigated.

METHODS

In this double-blind, randomized study, 288 preterm infants received experimental formula (n = 77), unsupplemented (control) formula (n = 78), or human milk (n = 133) until 48 weeks postconceptional age (PCA). Term formula, without supplemental long-chain polyunsaturated fatty acids, was administered from 48 to 92 weeks PCA to formula-fed infants and to infants weaned from human milk. Anthropometric and fatty acid data were assessed by using analysis of variance.

RESULTS

At 92 weeks PCA, no statistically significant anthropometric measurement differences were found except for midarm circumference, which was smaller in human milk-fed infants than in those fed formula. Phospholipid concentrations were similar in the experimental and human milk-fed groups, and docosahexaenoic acid levels were significantly greater than in the control group. The types and incidences of adverse events were similar among the feeding groups.

CONCLUSIONS

The results of this study demonstrate the efficacy and long-term safety of preterm formula supplemented with long-chain polyunsaturated fatty acids.

Antioxidant capacity and oxygen radical diseases in the preterm newborn

BACKGROUND

Bronchopulmonary dysplasia, intraventricular hemorrhage, necrotizing enterocolitis, and retinopathy of prematurity may be different manifestations of oxygen radical diseases of prematurity (ORDP).

OBJECTIVE

To test the hypothesis that the antioxidant capacity of cord blood serum will predict risk of ORDP.

DESIGN

An inception cohort of premature neonates was followed up from birth until discharge or death to determine if outcome was related to cord blood serum antioxidant capacity, as determined by a manual assay measuring the relative inhibition of oxidation of 2,2'-azino-di-(3-ethylbenzthiazoline)-6 sulfonic acid (ABTS). Possible correlations between antioxidant capacity and various perinatal factors were also tested.

SETTING

Level 3 newborn intensive care unit.

PATIENTS

All inborn very low-birth-weight neonates from whom cord blood was available and for whom maternal consent was obtained were included. Newborns who died in the first week of life or who had major congenital malformations were excluded. A convenience sample of newborns weighing more than 1500 g was used to perfect assay and explore confounders.

MAIN OUTCOME MEASURES

Significant ORDP was defined as the presence of intraventricular hemorrhage greater than grade 2, retinopathy of prematurity greater than stage 1, bronchopulmonary dysplasia at the postconceptional age of 36 weeks, or necrotizing enterocolitis with the hypothesis that neonates with ORDP will have lower antioxidant capacity in cord blood serum.

RESULTS

Serum antioxidant capacity at birth correlated with gestational age for the entire sample of 41 neonates and for the 26 neonates born before 32 weeks' gestation. After correction for gestational age, cord serum antioxidant capacity did not correlate with maternal smoking, preeclampsia, chorioamnionitis, cord pH Apgar scores, or any of the ORDP studied.

CONCLUSION

Cord serum antioxidant capacity correlates with gestational age but does not predict ORDP risk.

Spectral analysis of heart variability in the newborn infant

We investigated the relationship between spectral power and both mean heart rate (HR) and heart rate variability (HRV). Spectral power was calculated using digital heart rate recordings from term infants. Regression analysis revealed a positive correlation between low-frequency (LF) sympathetic power and HR, and a negative correlation between high-frequency (HF) parasympathetic power and HR. HRV correlated positively in all regions of the power spectrum. In awake infants, the contribution of HF power to total power (HF/TP) was significantly decreased. LF power tended to be greater, however, this trend was not statistically significant. By following expected autonomic patterns, the findings of this study confirm that spectral analysis provides a noninvasive method for the assessment of autonomic activity influencing the newborn heart. The correlation between spectral power and HRV can serve as an additional tool in the study of autonomic dysfunction.

Spectral analysis of heart rate variability in premature infants with feeding bradycardia

An elevated level of baseline parasympathetic activity was noted in a group of premature infants suffering from bradycardia during feeding. At approximately 34 wk post-conceptional age, the heart rates of 12 infants with feeding bradycardia (birth weight = 1539 +/- 279 g; gestational age = 31.0 +/- 1.6 wk) and 10 controls (birth weight = 1710 +/- 304 g; gestational age = 32.0 +/- 1.4 wk) were recorded 1 h before and 1 h after feeding. EKG data were digitized and 3.2-min segments of data were analyzed to determine the spectral power at very low (VLF = 0.003-0.03 Hz), low (LF = 0.03-0.39 Hz), and high (HF = 0.40-1.00 Hz) frequencies. In preterm infants with feeding bradycardia, an elevation in baseline parasympathetic activity was evident before feeding, as indicated by significantly higher HF power and a lower LF/HF ratio. This elevation in baseline parasympathetic activity may contribute to the observed bradycardia during feeding.

Antecedents and neonatal consequences of low Apgar scores in preterm newborns: a population study

BACKGROUND

To examine the antenatal and early neonatal correlates of low Apgar scores (<3 and <6 at 1 and 5 minutes) in preterm newborns (23-34 weeks' gestation).

OBJECTIVE

The use of Apgar scoring for premature newborns remains widespread, despite controversy regarding its reliability as a measure of morbidity and mortality in the neonatal period.

DESIGN

A cohort of 852 preterm newborns born during a 34-month period between 1984 and 1987 was studied. Newborns were stratified into 2 groups by gestational age (23-28 weeks and 29-34 weeks), and data were analyzed, controlling for gestational age in single weeks.

SETTING

Two academic and 1 community hospital, which together accounted for 83% of all preterm births in a tri-county area of central New Jersey during the study period.

PATIENTS

All premature newborns (birth weight <2000 g and gestational age <35 weeks) born in the participating hospitals during the study period were evaluated.

MAIN OUTCOME MEASURES

Antecedents included maternal illness during pregnancy, maternal complications of labor and delivery, and fetal heart rate abnormalities during labor and delivery. Consequences included delivery room resuscitation, abnormal physical findings, diagnoses, and therapeutic interventions in the first 6 to 8 hours of life.

RESULTS

Premature newborns with low Apgar scores received more cardiopulmonary resuscitation in the delivery room and in the first 6 to 8 hours of neonatal intensive care. Mortality was significantly increased among newborns with low Apgar scores (54% vs. 26% in the 23- to 28-week stratum, 30% vs 6% in the 29- to 34-week stratum). Newborns with low Apgar scores in the 29- to 34-week stratum more often required intubation, positive pressure ventilation, and umbilical vessel catheterization. Newborns with low Apgar scores had higher rates of bradycardia, pneumothoraces, acidosis, and increased oxygen requirement during the first 6 to 8 hours of life. Maternal illness, complications of labor and delivery;, and fetal heart rate decelerations did not correlate with subsequent Apgar scores of newborns. The presence of severe bradycardia (<90/min) and fetal heart rate accelerations correlated with low Apgar scores in the 29- to 34-week group.

CONCLUSION

Low Apgar scores are associated with increased neonatal morbidity and mortality in preterm newborns. Antenatal maternal history, and pregnancy complications are not clearly associated with low Apgar scores. Therefore, the Apgar score is a useful tool in assessing neonatal short-term prognosis and the need for intensive care among preterm newborns.

Umbilical vein interleukin 6 and tumor necrosis factor alpha plasma concentrations in the very preterm infant

OBJECTIVE

To examine the relationship between umbilical vein plasma concentrations of interleukin 6 (IL-6) and tumor necrosis factor (TNF)-alpha and early neonatal sepsis in the very preterm infant, and the histopathologic findings of chorioamnionitis in the placentas from these pregnancies.

METHODS

A prospective study was conducted in 43 very preterm, singleton infants delivered at or before 32 weeks of gestation. IL-6 and TNF-alpha were measured by enzyme-linked immunoassay. Placentas from these pregnancies were histologically examined for the presence of chorioamnionitis. Infants were prospectively classified as confirmed sepsis group, clinical sepsis group or control group. IL-6 and TNF-alpha plasma concentrations were not normally distributed, so they were transformed to their natural log values for statistical analysis.

RESULTS

The enrolled infants had a mean gestational age of 27.2 +/- 2.7 weeks and a mean birth weight of 956 +/- 325 g. Three (7%) infants had confirmed sepsis, 18 (42%) were in the clinical sepsis group and 22 (51%) were in the control group. IL-6 concentrations but not TNF-alpha were significantly higher (P < 0.05) in the confirmed (8.9 +/- 1.7) and clinical sepsis (5.5 +/- 2.4) groups in comparison with the control group (2.1 +/- 1.6). We examined 42 placentas. Twenty-three (55%) had no evidence of chorioamnionitis, 1 (2%) had mild grade, 8 (19%) had a moderate grade and 10 (24%) had a severe grade of chorioamnionitis. IL-6 was significantly elevated in the moderate (5.9 +/- 1.6 vs. 1.9 +/- 1.6) and severe grade (7.2 +/- 2.3 vs. 1.9 +/- 1.6) of chorioamnionitis, in the presence of acute deciduitis (6.0 +/- 2.7 vs. 2.1 +/-1.8), chorionic vasculitis (6.8 +/- 2.1 vs. 2.2 +/- 1.9) and funisitis (7.3 +/- 1.9 vs. 2.7 +/- 2.3) (P < 0.05) TNF-alpha plasma concentrations were not significantly different.

CONCLUSION

An elevated umbilical vein IL-6 concentration is a good indicator of sepsis syndrome in the very preterm infant and also correlates with histologic chorioamnionitis in these pregnancies.

Maternal infection, fetal inflammatory response, and brain damage in very low birth weight infants. Developmental Epidemiology Network Investigators

Echolucent images (EL) of cerebral white matter, seen on cranial ultrasonographic scans of very low birth weight newborns, predict motor and cognitive limitations. We tested the hypothesis that markers of maternal and feto-placental infection were associated with risks of both early (diagnosed at a median age of 7 d) and late (median age = 21 d) EL in a multi-center cohort of 1078 infants <1500 x g. Maternal infection was indicated by fever, leukocytosis, and receipt of antibiotic; fetoplacental inflammation was indicated by the presence of fetal vasculitis (i.e. of the placental chorionic plate or the umbilical cord). The effect of membrane inflammation was also assessed. All analyses were performed separately in infants born within 1 h of membrane rupture (n = 537), or after a longer interval (n = 541), to determine whether infection markers have different effects in infants who are unlikely to have experienced ascending amniotic sac infection as a consequence of membrane rupture. Placental membrane inflammation by itself was not associated with risk of EL at any time. The risks of both early and late EL were substantially increased in infants with fetal vasculitis, but the association with early EL was found only in infants born > or =1 after membrane rupture and who had membrane inflammation (adjusted OR not calculable), whereas the association of fetal vasculitis with late EL was seen only in infants born <1 h after membrane rupture (OR = 10.8; p = 0.05). Maternal receipt of antibiotic in the 24 h just before delivery was associated with late EL only if delivery occurred <1 h after membrane rupture (OR = 6.9; p = 0.01). Indicators of maternal infection and of a fetal inflammatory response are strongly and independently associated with EL, particularly late EL.

Evaluation of a long-chain polyunsaturated fatty acid supplemented formula on growth, tolerance, and plasma lipids in preterm infants up to 48 weeks postconceptional age

BACKGROUND

The last trimester of pregnancy is a period of rapid accretion of long-chain polyunsaturated fatty acids, both in the central nervous system and the body as a whole. Human milk contains these fatty acids, whereas some preterm infant formulas do not. Infants fed formulas without these fatty acids have lower plasma and erythrocyte concentrations than infants fed human milk. Preclinical and clinical studies have demonstrated that single-cell sources (algal and fungal) of long-chain polyunsaturated fatty acids are bioavailable. A balanced addition of fatty acids from these oils to preterm formula results in blood fatty acid concentrations in low birth weight infants comparable to those of infants fed human milk.

METHODS

In the present study the growth, acceptance (overall incidence of discontinuation, reasons for discontinuation, overall incidence and type of individual adverse events), and plasma fatty acid concentrations were compared in three groups of infants fed a long-chain polyunsaturated fatty acid-supplemented preterm infant formula, an unsupplemented control formula, or human milk. The study was prospective, double-blind (formula groups only), and randomized (formula groups only). Two hundred eighty-eight infants were enrolled (supplemented formula group, n = 77; control formula group, n = 78; human milk group, n = 133).

RESULTS

Anthropometric measurements at enrollment, at first day of full oral feeding, and at both 40 and 48 weeks postconceptional age did not differ between the formula groups, whereas the human milk-fed group initially grew at a lower rate. The incidence of severe adverse events was rare and not significantly different between formula groups. The groups fed either human milk or supplemented formula had long-chain polyunsaturated fatty acid concentrations higher than those in the control formula group.

CONCLUSIONS

The results of this study demonstrate the safety and efficacy of a preterm formula supplemented with long-chain polyunsaturated fatty acids from single-cell oils.

Heart rate and oxygen saturation correlates of infant apnea

OBJECTIVE

To analyze the effects of apnea duration on changes in heart rate and oxygen saturation and to examine the temporal relationships among these variables.

STUDY DESIGN

An event analysis sheet was designed to analyze numerous variables reflecting changes in heart rate and oxygen saturation associated with infant apnea. From July 1, 1991 through June 30, 1992 we identified 32 infants enrolled in The Infant Apnea Program at St. Peter's Medical Center, New Brunswick, NJ who had apnea > or = 15 seconds in duration on consecutive 12-hour multichannel recordings of heart rate, thoracic impedance, nasal thermistry, and oxygen saturation. The apnea epochs of these patients were subdivided into apnea of short (10 to 14 seconds), medium (15 to 19 seconds), and long (> or = 20 seconds) duration, and a total of 236 apnea epochs were analyzed. The significance of differences was assessed by analysis of variance and Newman-Keuls multiple comparisons.

RESULTS

We found that the duration of apnea has significant effects on perturbations in both heart rate and oxygen saturation, however, the degree of oxygen desaturation can not be predicted by the perturbation in heart rate. Analysis of the temporal relationship of apnea, bradycardia, and oxygen desaturation reveals that, although apnea precedes both heart rate and oxygen saturation drops in most infants as the length of apneic interval increases, the interval between apnea onset and associated drops in heart rate and/or oxygen saturation also increases.

CONCLUSION

Oxygen saturation monitoring may provide important physiologic data that can not be assessed by cardiorespiratory monitoring alone.

Developmental implications of head growth following intracranial hemorrhage

This study examined the association between head size at birth, discharge, and 1 year and developmental outcome at 1 year in preterm infants, with and without intracranial hemorrhages (ICH) or associated periventricular echodensities (PVE). The data indicated that most sick preterm infants with small heads at discharge achieved appropriate head sizes at 1 year. Analyses of the 1-year mental and motor performances of 125 subjects revealed that for subjects who did not develop ICH, appropriate head sizes at birth and discharge were associated with good developmental outcome, whereas infants with small heads (< two standard deviations below the mean for age) before hospital discharge were more likely to show poorer developmental outcome at 1 year. For subjects with ICH, birth and discharge head circumference were not predictive of 1-year developmental status; however, normal head size at 1 year was associated with better outcome. This was true for children with transient PVE as well. However, persistent periventricular echodensities were associated with both mental and motor deficits at 1 year, regardless of head growth.

The apgar score and its components in the preterm infant

OBJECTIVE

The Apgar score is well-characterized in full-term infants but not in premature infants. The objective of this study was to assess the Apgar score in preterm infants with respect to the relationships between the 1- and 5-minute scores, the correlation of the Apgar score with pH and with other variables, and the relationship among the individual Apgar components.

METHODOLOGY

We recorded Apgar scores at 1 and 5 minutes in a population-based cohort of preterm infants (n = 1105) with birth weight <2000 g, from three intensive care nurseries in central New Jersey. Linear correlation analysis was used to examine the relationship between 1- and 5-minute Apgar scores and between the individual components of the Apgar score. Multiple regression analysis was used to explore the relationship between various perinatal characteristics and the Apgar score, and between pH and Apgar score. Stepwise logistic regression analysis was used to assess the determinants of mortality.

RESULTS

The 1-minute Apgar score median (25%, 75%) was 6(4,8) and correlated with the 5-minute score of 8(7,9) at r = .78. Slight but significant differences were seen between male (n = 557) and female (n = 508) infants in the 1-minute (6[4,8] and 7[4,8]) Apgar scores. One- and 5-minute scores of white infants (7[4,8] and 8[7,9]; n = 713) were significantly higher than those of black infants (5[3,7] and 8[6,9]; n = 280). Birth weight and gestational age were both linearly related to both Apgar scores. Low Apgar score (<3 at 1 minute and <6 at 5 minutes) was significantly associated with birth weight, gestational age and mode of delivery. Low arterial blood pH (<7.01) at birth was significantly related to low Apgar score. One hundred fifty-nine infants died; these infants were significantly smaller (983 +/- 382 vs 1462 +/- 369 g), less mature (27 vs 31 weeks), had lower arterial blood pH (7.20 +/- 0.18 vs 7.31 +/- 0.11), had lower 1- (3[2,6] vs 7[4,8]) and 5-minute Apgar scores (6[4,8] vs 8[7,9]), and a greater incidence of low Apgar score (32% vs 6%) than did survivors.

CONCLUSIONS

Among the components of the Apgar score, respiratory effort, muscle tone, and reflex activity correlated well with one another; heart rate correlated less well; and color the least. Our data confirms the limited use of the Apgar score in preterm infants and demonstrates the different responses of the Apgar score's components.

Prolonged rupture of membranes in the term newborn

Of 8791 consecutive newborns, we studied 205 (2.3%) women with a history of prolonged rupture of membranes (PROM) greater than 24 hr to assess the incidence of infection, to identify the rate of clinical symptoms, and to examine the use of the white blood count (WBC) and neutrophil values as screening tools to predict infection. Blood culture and complete blood counts (CBC) were obtained in 175 (85%). Fifteen (8.2%) had positive blood cultures including group B streptococcus, streptococcus viridans, streptococcus pneumoniae, staphlococcus epidermidis, and staphlococcus aureus. In the remaining 8586 infants born to mothers without PROM, 10 had positive blood cultures for an incidence of 0.1%. In the PROM group, the six who manifested clinical symptoms had abnormal CBCs; abnormal white blood count (2), abnormal neutrophil count (5), high band/metatamyelocyte count (4), and increased immature to total neutrophil ratio (4). Of the nine asymptomatic infants, seven (78%) had abnormal CBCs, five (56%) with a high WBC, five (56%) had a high neutrophil count, two (22%) had a high band/metatamyelocyte count, and one a high immature to total neutrophil ratio. CBC values were obtained from infants with PROM and negative blood cultures. Five of these 15 controls had an abnormal CBC. In the term newborn, PROM is associated with significantly increased incidence of positive blood cultures. The sensitivity of the CBC was 86% and specificity 66%. In view of this data a conservative clinical approach utilizing blood cultures and CBC evaluations in the management of PROM is warranted.

Maternal receipt of magnesium sulfate does not seem to reduce the risk of neonatal white matter damage

OBJECTIVE

To investigate whether in utero exposure to magnesium sulfate is associated with a lower incidence of cranial ultrasonographic abnormalities that predict cerebral palsy in infants who weigh less than 1501 g at birth.

DESIGN

For a prospective study of the antecedents of cranial ultrasonographic abnormalities, we enrolled infants who weighed 500 to 1500 g when born at five institutions. Data were collected by interview of the mothers and review of medical records. Protocol cranial ultrasonograms were obtained as close as possible to postnatal days 1, 7, and 21. Abnormality on cranial ultrasound scans was determined by a consensus committee of three sonologists.

RESULTS

Of the 1518 infants for whom we knew whether the mothers received magnesium sulfate, the first protocol cranial ultrasound scan was available for 1409 infants, the second for 1274 infants, and the third for 1050 infants. Forty-five percent of infants were exposed to magnesium sulfate before delivery. The major correlates of magnesium sulfate exposure were receipt of antenatal corticosteroids and a diagnosis of preeclampsia and/or pregnancy-induced hypertension. Maternal magnesium receipt was not associated with a reduced incidence of hypoechoic or hyperechoic images of white matter parenchyma, intraventricular hemorrhage, or ventriculomegaly, even when the sample was stratified by each of six potential confounders. When adjustment was made for gestational age, a measure of birth weight for gestational age, antenatal corticosteroid exposure, preeclampsia and pregnancy-induced hypertension, route of delivery, and the occurrence of any labor, the risk ratios for each cranial ultrasonographic abnormality associated with magnesium sulfate exposure hovered close to 1.

CONCLUSION

Maternal receipt of magnesium sulfate does not seem to be associated with an appreciably reduced risk of cranial ultrasonographically defined neonatal white matter damage, intraventricular hemorrhage, or ventriculomegaly.

Serum levels of unbound free fatty acids. I: Normative data in term newborn infants

BACKGROUND

Free fatty acids (FFA) play essential roles in maintaining physiologic homeostasis in the newborn infant. Most of the FFA in serum is carried in complex with albumin, but a small fraction remains unbound in the aqueous phase.

OBJECTIVE

This study's goal is to report the values of serum levels of unbound free fatty acids (FFAu) in pregnant women and their newborn infants at term gestation.

METHODS

The measurements were made possible by the availability of the fluorescent probe for unbound FFA, acrylodated intestinal fatty acid binding protein (ADIFAB). Twenty-two mother-infant pairs were enrolled in the study. Maternal levels were obtained immediately before delivery, cord levels at the time of delivery, and infant levels after 24 hours of age.

RESULTS

The level of FFAu measured in maternal samples was 11.8 +/- 4 nM, in cord samples 9.2 +/- 4 nM, and in infants 13.9 +/- 3 nM. These population averages are considerably greater than those observed in healthy adults (7.5 +/- 2.5 nM). No correlation was found between cord levels and birthweight, gestational age, labor duration, mode of deliver, and infant or maternal temperature.

CONCLUSIONS

This investigation is the first to measure FFAu in a group of mothers and their infants and provides the technique for future investigations of the biologic activity of free fatty acids.

Serum levels of unbound free fatty acids. II: The effect of intralipid administration in premature infants

BACKGROUND

Fatty acids (FFA) are key nutrients in maintaining physiologic homeostasis and in the form of Intralipid administration, they are important sources of nutrition in the premature newborn infant. Complexed with albumin, fatty acids have a small but important fraction that remains unbound in the aqueous phase.

OBJECTIVE

The goal of this study was to examine the levels of serum levels of unbound free fatty acids (FFAu) in premature newborns following Intralipid administration.

METHOD

A fluorescent probe acrylodated intestinal fatty acid binding protein (ADIFAB) was used to measure (FFAu) before Intralipid and during increasing rates of infusion.

RESULTS

There were significant differences between (FFAu) values obtained before Intralipid and levels after the infusion of 1.0, 2.0, and 3.0 g/kg/day (p < 0.05). Regression analysis of Intralipid dose and FFAu yielded an r = 0.438 and the following relationship: [FFAu] = 26.39 + 3.60 * IL (g/kg/day).

CONCLUSIONS

Intralipid administration results in significant elevation of FFAu in the very low birth weight infant.

Blood pressure ranges in premature infants: II. The first week of life

OBJECTIVE

To examine the arterial blood pressure in the first week of life in a healthy premature population.

DESIGN

Population-based cohort study.

SETTING

Three intensive care nurseries in central New Jersey.

PATIENTS

Premature infants with birth weights less than 2000 g.

MAIN OUTCOME MEASURES

We documented daily maximum and minimum systolic and maximum and minimun diastolic blood pressures during the first 7 days of life. To examine the effects on the ranges of blood pressure, we identified four groups of infants: (1) healthy infants without any of the major risk factors (n = 193); (2) infants who were mechanically ventilated but free of any of the other conditions (n = 225); (3) infants with histories of maternal hypertension or preeclampsia (n = 38) and (4) infants with low Apgar scores (less than 3 at 1 minute and less than 6 at 5 minutes) regardless of the presence of other conditions (n = 86).

RESULTS

Blood pressure increased steadily in the first week of life in all four groups. There was no relationship between any of the four blood pressure variables, or trends in blood pressure over time, with birth weight, gender, or race. Regression equations (based on all infants with available data) for blood pressure ranges by day of life revealed that the maximum systolic blood pressure increased by 2.6 mm Hg/d, the minimum systolic blood pressure increased by 1.8 mm Hg/d,the maximum diastolic blood pressure increased by 2.0 mm HHg/d, and the minimum diastolic blood pressure increased by 1.3 Hg/d.

CONCLUSIONS

Infants with birth asphyxia and ventilated infants had significantly lower systolic and diastolic blood pressures than healthy infants.

The incidence of gastroesophageal reflux in preterm infants

We observed an increased incidence of gastroesophageal reflux (GER) in a group of preterm infants. Seventy-five infants (birth weight 1117 +/- 242 gm, gestational age 30 +/- 3 weeks) were tested within 1 week before hospital discharge (37 to 38 weeks postconceptional age). All of the infants had a two-channel pneumocardiogram and a 1-hour esophageal pH study (Tuttle test). Home monitors were used for all infants after hospital discharge and their use was maintained until standard discontinuation criteria were achieved. The Tuttle test was abnormal in 47 (63%) of the infants. Of the 47 infants with GER, 22 (47%) had evidence of obstructive apnea during the periods of reflux and 32 (68%) had an abnormal PCG result. Thirty-eight (81%) of the infants with GER had episodes of either obstructive or central apnea. The diagnosis of GER is important in premature infants because of the high association with recurrent or obstructive apnea.

Efficacy of surfactant therapy in infants managed with CPAP

Surfactant rescue therapy can be utilized effectively early in the course of respiratory distress syndrome (RDS) in infants weighing > 1,000 g and treated exclusively with continuous positive airway pressure (CPAP) therapy. Thirteen infants (BW, 1,774 +/- 580 g; GA, 31 +/- 3 weeks) comprising the CPAP/SURFACTANT group were compared with 12 infants (BW, 1,753 +/- 556 g; GA, 31 +/- 2 weeks) who comprised the intermittent mandatory ventilation (IMV)/surfactant group, and with 14 infants (BW, 1,776 +/- 332 g; GA, 32 +/- 2 weeks) treated with CPAP before surfactant was clinically available. A 5 mL/kg dose of Exosurf Neonatal (Burroughs-Wellcome) was administered to infants intratracheally when the FiO2 requirement reached 0.40 to maintain the PO2 above 50 torr. Infants in the CPAP/surfactant group were intubated solely for surfactant administration and extubated within 18 +/- 6 min of treatment. The CPAP/surfactant group was treated at a mean age of 12.3 +/- 9.3 h, and the IMV/surfactant group at 10.2 +/- 9.8 h. Alveolar-arterial oxygen gradient (AaDO2), oxygenation index (OI), and mean airway pressure (MAP) were determined immediately before and after surfactant therapy, and at comparable times for the CPAP-only group. A significant difference was found in pre-treatment AaDO2, OI and MAP between the CPAP/surfactant group and IMV/surfactant group, but not between the CPAP/surfactant group and the CPAP-only group. Similarly, a significant difference in AaDO2, OI and MAP continued post-treatment was noted. However, a significant difference was also found at this time between the CPAP/surfactant group and the CPAP-only group. In addition, a significant difference was noted in AaDO2 and OI pre- and post-treatment within each surfactant-treated group. Furthermore, in the CPAP-only group AaDO2 and OI actually worsened (212 +/- 70 vs. 239 +/- 68; 4.0 +/- 1 vs. 4.5 +/- 2, respectively). There was a significant reduction in the duration of oxygen therapy (3 +/- 2 vs. 5 +/- 2 vs. 4.5 +/- 2 days, respectively) as well as in the total days of hospitalization (30 +/- 10 vs. 42 +/- 15 vs. 43 +/- 12 days, respectively). We conclude that in this small group of infants surfactant administration was effective and safe. It appeared to improve the course of RDS and shorten the duration of oxygen exposure and days of hospitalization.

The protective role of bilirubin in oxygen-radical diseases of the preterm infant

We hypothesized that because bilirubin is a potent free-radical quencher, infants without disorders that have oxygen-radical disease (ORD)-mediated mechanisms may have higher bilirubin levels than infants suffering from conditions possibly associated with ORD-mediated mechanisms (e.g., necrotizing enterocolitis, broncopulmonary dysplasia, intraventricular hemorrhage, and retinopathy of prematurity). We identified 25 infants (birth weight 912 +/- 208 gm, gestational age 27 +/- 3 weeks) who comprised the ORD group and compared them with 57 controls (birth weight 1242 +/- 248 gm, gestational age 31 +/- 3 weeks). Infants with ORD had lower peak serum bilirubin concentrations, later ages at peak, and lower incidence of peak bilirubin concentrations exceeding 10 or 15 mg/dl. In addition, these infants exhibited a slower rate of bilirubin rise and a smaller area under the bilirubin-time curve measure compared with controls. To control for different birth weights, we analyzed subgroups weighing < 1000 gm. Significant differences were again identified in peak bilirubin concentrations, age at peak, phototherapy duration, and area under the curve. In this population of preterm infants, higher bilirubin levels were associated with a lower incidence of oxygen radical-mediated injury.

Blood pressure ranges in premature infants. I. The first hours of life

We studied blood pressure in the first hours of life in a cohort of 1105 preterm infants weighing 501 to 2000 gm; these infants represented 83% of all births at these weights that resulted in admission to three intensive care nurseries during a 34-month period between 1984 and 1987. To assess the effects of specific risk factors, we identified 244 healthy infants, 164 infants who received mechanical ventilation but had no other conditions, 47 infants whose only risk factor was the presence of hypertension or preeclampsia in the mother, and 86 infants with depressed Apgar scores regardless of the presence of the other conditions. We documented each infant's minimum and maximum systolic (Smin, Smax) and diastolic (Dmin, Dmax) pressures during the first 3 to 6 hours of life. In the healthy group, Smin was 47 mmHg; Smax, 59 mmHg; Dmin, 24 mmHg; and Dmax, 35 mmHg. In the ventilation group, Smin was 41 mmHg; Smax, 57 mmHg; Dmin, 22 mmHg; and Dmax, 35 mmHg. The Smin and Dmin values were both significantly lower in infants who received mechanical ventilation than in healthy infants (p < 0.01). In the maternal hypertension group, Smin was 49 mmHg; Smax, 59 mmHg; Dmin, 25 mmHg; and Dmax, 34 mmHg. Only the Smin value was significantly higher than in healthy infants. In the group with low Apgar scores, Smin was 33 mmHg; Smax, 51 mmHg; Dmin, 19 Hg; and Dmax, 34 mmHg. Thus all these values were significantly lower than in all the other groups (p < 0.05). Of infants with low Apgar scores, 20% to 50% had values below the 5th percentile for healthy infants. Birth weight and gestational age correlated with blood pressure limits only in the infants with low Apgar scores. We conclude that in healthy premature infants the limits of systolic and diastolic blood pressure are independent of birth weight and gestational age. Infants with low Apgar scores tend to have lower pressures, and infants whose mothers have hypertension have higher pressures than infants in the healthy cohort.

The ventilatory response to carbon dioxide in high risk infants

PURPOSE

To examine the ventilatory response to inspired carbon dioxide in infants considered to be at risk for sudden infant death syndrome or apnea.

DESIGN

Clinical data measurement.

SETTING

Infant apnea evaluation program of a university division of neonatology.

PATIENTS

Fifty nine infants were full term characterized by the following diagnoses; siblings of infants who had died from sudden infant death syndrome (SIDS) (n = 7), apparent life threatening event (ALTE) (n = 24), apnea/cyanosis in the newborn nursery (n = 21), and controls. Sixty-nine infants were preterm and consisted of patients suffering from idiopathic apnea (n = 61), and bronchopulmonary dysplasia (n = 8).

MEASUREMENTS

The ventilatory response to carbon dioxide was measured with a computerized waveform analyzer.

MAIN RESULTS

Among full term infants no significant differences in the ventilatory slope in response to CO2 was seen. The range of mean slope was 19.4 +/- 7.6 in siblings of SIDS and 36 +/- 17 in control infants. Greater number of sibling of SIDS had slopes less than 20 ml/kg/min/mmHg in comparison to control infants. Sibling of SIDS had less increase in minute ventilation and inspiratory flow in response to CO2 administration in comparison to control infants. Preterm infants had similar slopes with a mean of 33 ml/kg/min/mmHg in infants with idiopathic apnea and 28 ml/kg/min/mmHg in infants with bronchopulmonary dysplasia.

CONCLUSIONS

The large intragroup variability in the ventilatory response to inspired CO2, confirming previously reported data, comprises the benefit of this test. Thus, ventilatory response to CO2 administration is not useful in unselected patients at risk of SIDS or apnea.

Incidence and timing of germinal matrix/intraventricular hemorrhage in low birth weight infants

Incidence and time of onset of germinal matrix/intraventricular hemorrhage (GM/IVH) were prospectively ascertained in 1,105 infants weighing < or = 2,000 g at birth, a cohort comprising about 85% of all births of that weight born from September 1984 to June 1987 in the central New Jersey counties of Ocean, Monmouth, and Middlesex. Cranial ultrasonography was performed as nearly as possible to age 4 hours, 24 hours, and 7 days. Each scan was reviewed by two independent readers and, if necessary, a third; consensus was achieved on scan of first diagnosis of GM/IVH in 965 of the 1,079 infants with assessable scans. The cumulative incidence of GM/IVH in the first week of life was 24.6% (265/1,079). In the 965 infants with consensus diagnoses, the first scan, at 4.9 +/- 2.2 hours, yielded the highest incidence--10.6% (95/899). Incidence by the second scan (25.1 +/- 4.9 hours) was 6.0% (49/813), and by the third scan (7.2 +/- 0.8 days), 9.0% (64/715). The iterative algorithm for interval-censored data developed by Turnbull (J R Stat Soc [B] 1976;8:290-5) was used to estimate the most likely time of onset based on time of first diagnosis. From 34% to 44% of hemorrhages were present at the first opportunity to scan, which in these data was at age 1 hour. At least a third of GM/IVH in infants < or = 2,000 g appears to be of congenital or immediate postnatal onset.

Maternal grief after sudden infant death syndrome

Six months after the death of their infants of Sudden Infant Death Syndrome (SIDS), the subjective impression of mothers anonymously rating their initial and present grief was that there had been a reduction in all symptoms (p < .001). However, an increase in the relative ranking of some cognitive symptoms over somatic ones, the association of certain lifestyles and situational variables with higher levels of grief, and the implication for future symptoms of family decisions made during bereavement underscore the importance of continuing active support for these families. In relative ranking, guilt rose from 10th to 5th most prominent symptom, particularly among the 34% of mothers whose infants manifested clinical symptoms (p < .05). Single mothers had higher grief scores both initially (p < .05) and at 6 months (p < .002), were almost three times more likely to become pregnant within 6 months of the death but only one-third as likely to attend a support group, and were also more likely to move after the death (44% vs 25%). Mothers whose infants had been discovered by another caregiver reached out more to a crisis intervention service of a support program available to SIDS families (p < .05). Mothers without surviving children had grief levels comparable with those with children but were less likely to rate their pediatrician's support as satisfactory, increasing the probability that they would change physicians with subsequent children, thereby losing continuity of care and support.

Neurodevelopmental outcome of infants with apnea of infancy

The neurodevelopmental outcome of premature infants with persistent apnea of prematurity (AOP) is reported. Sixty premature infants (birthweight [BW], 1469 +/- 533 gm; gestational age [GA , 31 +/- 3 weeks) with AOP were compared to 47 control infants (BW, 1586 +/- 581 gm; GA, 31 +/- 3 weeks) matched for gestational age and degree of neonatal illness. The infants were enrolled in a multidisciplinary follow-up program, and outcome data between 12 and 24 months are reported. Assessments included the Bayley Scores of Infant Development, neurologic examinations, speech and hearing examinations. There were no significant differences in the cognitive outcome between the premature infants with AOP and the premature control group. In 50 of 60 infants the Bayley Mental Developmental Index was in the normal range (112 +/- 18) as was 39 of 47 of the control group (112 +/- 13). Delays in motor development were seen in both premature groups, although a greater percentage of premature infants with persistent apnea had mild motor delays than did control infants. There was a comparable incidence of cerebral palsy (8% vs 11%), speech delays (20% vs 23%), retinopathy (8% vs 13%), and esotropia (7% vs 4%) between the infants with AOP and the premature control infants. The presence of persistent neonatal apnea without additional adverse perinatal events did not appear to be associated with a higher incidence of significant developmental problems.

Digital subtraction angiography--a new approach to brain death determination in the newborn

The diagnosis of brain death in the newborn infants is elusive and often difficult. The lack of cerebral blood flow has become an identified criterion for loss of cerebral function. The diagnosis can be obtained by the technique of digital subtraction angiography, which is presented in two case reports demonstrating the utility of this technique.

Cerebral blood flow measurements in the newborn dog

Current methods of cerebral blood flow (CBF) determination provide only discrete, episodic data and are limited in assessing dynamic changes in cerebral circulation. We adapted a venous outflow technique employing cannulation of the superior sagittal sinus in newborn puppies to measure changes in CBF rapidly and sequentially during ventilatory maneuvers. CBF velocity (CBFV) was measured simultaneously with Doppler ultrasound of the anterior cerebral artery. Relationships between flow and velocity were determined during hypocarbia, hypercarbia, hypoxia and asphyxia. During hyperventilation, CBF decreased by a mean of 14%, and CBFV by 13%, whereas maximal CO2 inhalation increased CBF by 59% and CBFV by 110%. Although CBFV exhibited the same directional changes as shown by the area under the velocity curve, the magnitude of change was not proportional to flow. CBFV indicated trends in the direction of changes in flow in individual animals, but did not correlate with flow between animals. A fluctuating unstable pattern of CBFV, previously associated with neonatal intracranial hemorrhage, was demonstrated with hyperventilation and hypocarbia. During asphyxia, CBFV ceased 2-5 min prior to CBF, presumably reflecting continued brain perfusion from vessels other than anterior cerebral artery.

Sudden infant death syndrome in 1992: the known and unknown

Sudden infant death syndrome (SIDS) continues to be the leading cause of death in infants from one month to one year of age. We present the results to the Fifth Annual Perspectives on SIDS. This program is one component of the educational services of the New Jersey SIDS Resource Center.

Sudden infant death syndrome in New Jersey: 1991

Sudden infant death syndrome (SIDS) is the leading cause of death in infants one month to one year of age. The New Jersey Sudden Infant Death Syndrome Resource Center gathers epidemiological data on all SIDS deaths in New Jersey, noting differences in population and countries.

Visitation to a neonatal intensive care unit

Preterm newborns may experience extended periods of hospitalization which disrupt the normal early contact between the newborn and its family. Variations in the frequency of visits to 164 preterm neonates in a neonatal intensive care unit were examined in relation to infant and family status variables and compliance with follow-up appointments at 3 months postterm. The mean number of visitors decreased from day 2 to day 12 of hospitalization and then remained stable through day 21. There was a corresponding increase in the number of days with no visitors through day 12, and then stabilization. Neonates who had intraventricular hemorrhages, whose parents did not live together, and who were not firstborn had the most days with no visitors. While the mother was hospitalized herself, her condition was the only variable related to percentage of no-visitor days. The sicker the mother, the more likely the newborn had no visitors. The greater the number of days with no visitors, the poorer the likelihood that the infant was brought to a 3-month follow-up clinic appointment.

The four-channel pneumogram in infants with recurring apneas and bradycardias

The two-channel pneumocardiogram (PCG) is frequently used for evaluating infants at risk for infantile apnea. In this study, the two-channel PCG failed to identify a significant number of symptomatic infants that were diagnosed by a four-channel pneumocardiogram. Nine infants suffering from either apparent life-threatening events (ALTE) or persistent apnea of prematurity were evaluated with two- and four-channel PCGs. The four-channel PCGs consisted of the standard two-channel evaluations, ECG and impedance pneumography, expanded by the addition of pulse oximetry and nasal thermistry. The PCGs were evaluated in a blinded manner by three trained observers. Each PCG was evaluated in both the two- and four-channel mode. A PCG was considered abnormal when any of the following was present: (1) a heart rate deceleration greater than one third of the baseline and lasting more than 8 seconds, (2) an apneic pause, either by impedance or by airflow, of greater than 20 seconds, (3) evidence of obstructive apnea less than 20 seconds but associated with cardiac deceleration, and (4) evidence of oxygen desaturation below 85% and lasting more than 8 seconds. All nine of the infants studied had recurrent apneic episodes at home. The four-channel PCGs were abnormal in all of the infants studied, whereas only four of the two-channel PCGs were abnormal (P less than .02). In this population, over 50% of the infants were incorrectly evaluated by the standard two-channel PCG and correctly identified by the four-channel PCG.

Undetected apnea and bradycardia in infants

Despite routine monitoring, a number of prolonged apneic and bradycardic episodes were undetected in a group of infants in the neonatal intensive care unit (NICU). Sixty-one infants were evaluated by 12-hour pneumocardiograms at a post-conceptional age of 35 +/- 3 (SD) weeks. Nursing documentation failed to detect 11 infants with prolonged apnea and bradycardia. Three of these infants were not detected in spite of increased awareness following in-service education. Such a lack of documentation may lead to improper medical management of infants at risk for pathologic apnea and suggests the need for more accurate documentation at the time of discharge.

Surfactant replacement therapy

The field of neonatology has experienced exceptional growth in recent years, and several excellent facilities exist in New Jersey for the care of premature and sick newborn infants. This article describes important advances made in the management of neonatal respiratory distress syndrome.

Prenatal lidocaine and the auditory evoked responses in term infants

We examined the effects of maternal lidocaine hydrochloride anesthesia on the brain-stem auditory evoked responses (BAERs) in neonates born by cesarean delivery. Sixteen term neonates were enrolled in the study. Eight neonates were delivered by cesarean section following lidocaine anesthesia, and eight were delivered by spontaneous vaginal delivery without maternal anesthesia. A BAER was obtained on all of the neonates on the first day of life. A significant delay was noted in the central neural component of the BAER at 90 dB. The wave I through V interpeak latency for both ears was noted to be 5.3 ms for the neonates exposed to lidocaine and 4.9 ms for the controls.

Prevention of hypoxia and hyperoxia during endotracheal suctioning

A new suction catheter, designed to deliver alternately oxygen or suction, prevented episodes of hypoxia and hyperoxia in a group of infants during endotracheal suctioning. Twenty infants received both conventional endotracheal suctioning and suctioning by the new catheter. The infants had a maximal change from a presuctioning transcutaneous oxygen (PtcO2) of 12 +/- 8 torr and required 3.1 +/- 2 min to regain their presuctioning oxygenation level compared to a maximal change of 21 +/- 10 torr (p less than .05) and a stabilization time of 5.3 +/- 2.6 min (p less than .05) in the conventionally treated group. Three study infants experienced an abnormal PtcO2 (either less than 40 or greater than 90 torr), while 13 control infants suffered these abnormalities (p less than .01). The use of this new suction device effectively reduced the exposure of this group of infants to episodes of aberrant oxygen states and allowed for a shorter recovery time.

Esophageal perforation in the neonate: an emerging problem in the newborn nursery

We report 11 cases of esophageal perforation in the neonate, in whom no surgery was performed for repair of the perforation, nor was any cervical or mediastinal drainage carried out. The perforation was in the cervical esophagus in all cases where an esophagram was performed. Nine were in premature babies (580 to 1,350 g), and two were full-term babies. There were two deaths in small prematures (580 and 935 g), from extreme prematurity and intraventricular hemorrhage, with no morbidity or mortality related to the esophageal perforation. The babies presented as esophageal atresia, or pneumothorax with the feeding tube in the right chest, or an abnormal right upper extrapleural air collection with infiltrate. Barium esophagram showed a classic "double esophagus" configuration. Two babies were mistakenly operated on, one with a diagnosis of esophageal duplication, and one had a gastrostomy for a diagnosis of esophageal atresia. Esophageal perforation in the neonate is an iatrogenic disease that may mimic esophageal atresia, and may be managed without surgical intervention.

Evaluation of routine lumbar punctures in newborn infants with respiratory distress syndrome

Infants with respiratory distress syndrome are routinely evaluated for infection which commonly includes a lumbar puncture. In this study cerebrospinal fluid (CSF) examination failed to elicit evidence for meningitis in 238 consecutively admitted infants with respiratory distress syndrome evaluated during the first 24 hours of life. Blood cultures were obtained in all; suprapubic or catheterized urine was obtained in 163 infants; CSF was collected successfully in 203 infants. Seventeen infants demonstrated positive blood cultures: 7 Streptococcus, 5 Staphylococcus, 3 Haemophilus influenzae, 1 Bacillus subtilis and 1 diphtheroid infection. CSF obtained from 14 of those infants had normal examinations and sterile cultures. Factors associated with bacteremia were birth weight (P less than 0.01), gestational age (P less than 0.01), prolonged rupture of membranes (P less than 0.05) and leukopenia below 10 000/mm3 (P less than 0.05). In view of the negative CSF examinations in infants with positive blood cultures and the potential complications of lumbar puncture (hypoxia, trauma, infection, epidermoid tumor), the potential risks of CSF evaluation may exceed the assessed benefit for the infant with respiratory distress syndrome.

Ventilatory response to inspired carbon dioxide in premature infants recovering from intraventricular hemorrhage

We examined the ventilatory response to inhaled carbon dioxide with a computerized waveform analyzer in two groups of premature infants. Twenty-seven infants suffered from periventricular-intraventricular hemorrhage (IVH) during the first week of life and comprised the study group (birth weight 1.2 +/- 0.2 kg, gestational age 29 +/- 2 weeks). The control group consisted of 15 infants without IVH (birth weight 1.4 +/- 0.3 kg, gestational age 30 +/- 2 weeks). Study infants were evaluated at a postnatal age of 9 +/- 2 weeks and control infants at 7 +/- 3 weeks. No differences were found in the slope or position of the ventilatory response curve, baseline PACO2, increase in minute ventilation, VT/Ttot, and Ti/Ttot between the two groups. Subgroups with unresolved apnea (10 IVH and eight control infants) demonstrated a rightward shift of the ventilatory response curve compared to those infants without apnea. A previous IVH did not reduce the ventilatory response to CO2 in this group of infants.

The course of hyperbilirubinemia in the very low birth weight infant treated with phenobarbital

We examined the effect of early phenobarbital therapy on the course of jaundice in 57 infants with birth weight below 1,500 g. The study group of 28 infants was treated with a phenobarbital loading dose of 20 mg/kg at 4.2 (3.6) [mean (SD)] hours of age, followed by a maintenance dose of 5 mg/kg/day for one week; 29 infants served as controls. Seventeen study and 19 control infants suffered from periventricular-intraventricular hemorrhage (IVH). The two groups had comparable risk factors that can potentially affect the course of hyperbilirubinemia. Peak serum bilirubin concentration was 7.9 (1.8) mg/dl in the treated group and 8.6 (2.2) mg/dl in the control group. Three infants in the treated group and seven infants in the control group had peak serum bilirubin concentration above 10 mg/dl. These differences in the peak serum bilirubin concentration or in the number of infants with peak serum bilirubin concentrations above 10 mg/dl are not statistically significant. However, treated infants achieved peak serum bilirubin concentration earlier (mean age 90 hours as compared to 138 hours in control infants), and required phototherapy for a shorter duration of time (5.5 days in the treated group as compared to 7.5 days in the control group). While these differences in the two groups with regard to age of peak serum bilirubin concentration and duration of phototherapy are statistically significant, they do not seem to be clinically important. Thus, in our group of very low birth infants phenobarbital failed to show any clinically important effects on the course of jaundice when used in conjunction with phototherapy.

The pharmacokinetics of naloxone in the premature newborn

We examined the pharmacokinetic properties of naloxone in a group of premature infants infused with an intravenous bolus of the drug. Ten infants with a mean birth weight of 1,328 +/- 402 g and a gestational age of 29.4 +/- 2.8 weeks were studied at an age of 4.5 +/- 3.2 days of life. Following administration of 0.4 mg/kg of naloxone, we obtained blood samples at specific time intervals, and stored the serum for later analysis by a radioimmunoassay method. Calculations from the serum concentration versus time relationship resulted in an elimination rate constant of 0.75 +/- 0.39/h, a half-life of 70.5 +/- 35.2 min, a systemic clearance of 39.13 +/- 14.53 ml/min/kg, and an apparent volume of distribution of 3.52 +/- 1.20 liters/kg.

Compliance measurement in respiratory distress syndrome: the prediction of outcome

Dynamic compliance (Cdyn) measurements within the first three days of life predicted survival in 60 preterm infants suffering from respiratory distress syndrome. Cdyn was measured in 47 survivors at 2.3 +/- 1.4 days of life and in 13 nonsurvivors on 2.7 +/- 1.7 days. All nonsurvivors died from respiratory failure within the first two weeks of life. Mean Cdyn of the survivors was 0.83 +/- 0.33 ml/cm H2O and of the nonsurvivors 0.35 +/- 0.19 ml/cm H2O (p less than 0.001). Cdyn values below 0.45 ml/cm H2O predicted 11 of 13 deaths in infants, and Cdyn measurements above this value predicted 45 of 47 survivals, with a specificity of 81% and a sensitivity of 89%. Eleven of the survivors, who subsequently developed bronchopulmonary dysplasia (BPD), had a mean Cdyn of 0.56 +/- 0.23 ml/cm H2O. When these infants were matched with infants of comparable weight without evidence of BPD, the BPD group had a significantly lower Cdyn (p less than 0.05). Cdyn measurements during the first three days of life are useful in predicting outcome of respiratory failure secondary to respiratory distress syndrome.