Postnatal physiologic hypercholemia in both premature and full-term infants.

Previous studies have shown that bile salt concentrations in human blood taken from the placenta at birth of term infants are in the range found in adults. A 125I-radioimmunoassay procedure and capillary gas liquid chromatography-mass spectrometry have been used in this investigation to measure serum bile salt concentrations in premature and normal term infants. It was found that the serum bile salt concentration in samples taken at birth in premature infants were also similar to that of adults. In the week after birth the serum bile salt concentration rose four- to sevenfold in each of the infant groups. The increase was independent of gestational age and the "health" of the child. A similar increase was observed in term infants. Thus, hypercholemia is physiologic in newborn infants. In conjunction with other abnormalities of the enterohepatic circulation of bile salts there are profound implications in the newborn for the metabolism and excretion of those endogenous and exogenous substances that are dependent on the secretion of bile salt by the liver. In addition, speculations concerning the role of parenteral nutrition in the induction of cholestasis in premature infants should be made with caution.

Use of Limulus lysate for detecting gram-negative neonatal meningitis.

The Limulus lysate test was evaluated as a method for rapid detection of neonatal gram-negative bacterial meningitis. A total of 208 CSF samples were collected from 145 newborn infants suspected of having meningitis. Initial samples from all six babies with culture-proven gram-negative bacterial meningitis had positive Limulus tests within 30 minutes of incubation. Samples from 14 infants with gram-negative organisms isolated only in blood and/or urine as well as from four neonates with gram-positive organisms in CSF cultures and from 13 with gram-positive organisms in blood cultures all yielded negative Limulus tests. Thus, of 37 newborn infants with bacteria demonstrated in systemic cultures, only those six with gram-negative organisms in CSF had positive CSF Limulus tests. The CSF Limulus test was shown to be a rapid, reliable, and specific test for the detection on neonatal gram-negative bacterial meningitis.

Endotracheal intubation and its relationship to bacterial colonization and systemic infection of newborn infants.

The role of antibiotics in preventing respiratory tract bacterial colonization and systemic infection after orotracheal intubation was prospectively studied in 54 newborn infants. Respiratory tract colonization was assessed from nasopharyngeal and tracheal aspirate cultures obtained at intubation and daily thereafter, while systemic infection was monitored by blood, cerebrospinal fluid, and suprapubic urine cultures performed initially and every three days thereafter while intubated. Colonization and systemic cultures were also obtained at extubation or death. The study group, provided with antibiotics at intubation, and the control group were similar in birthweight and gestational age, as well as race, sex, hospital or origin, and indication for intubation. Colonization at intubation was five times more common in infants intubated 12 or more hours after birth than in infants intubated earlier. Subsequent colonization was twice as frequent in infants intubated longer than 72 hours as well as in those requiring two or more reintubations. Systemic infection occurred only in those infants who were initially or subsequently colonized and was three times more frequent in the control group than in the study group.

Relation between arterial blood pressure and blood volume and effect of infused albumin in sick preterm infants.

The relation between directly measured arterial blood pressure and blood volume was studied in 61 sick preterm infants. Mean blood volume (derived from plasma volume [T1824 ten-minute albumin space] and hematocrit value) of 26 hypotensive infants (89.1 +/- 17.26 ml/kg) was not significantly different from that of 35 normotensive, but otherwise comparable, infants (91.4 +/- 14.57 ml/kg). There was no relation between arterial mean blood pressure and blood volume. Twenty-one infants with arterial mean blood pressure less than 30 mm Hg were given 1.0 g/kg of 10% salt-poor albumin. Significant increases in blood pressure occurred but were small in magnitude; more than one half of infants had arterial mean blood pressures persistently less than 30 mm Hg. Arterial/alveolar PO2 ratio decreased significantly with albumin infusion in six infants with hyaline membrane disease not receiving continuous distending-airway pressure, suggesting an association between infused albumin and impaired oxygen exchange.

Feeding the low-birthweight infant: orally or parenterally?: II. Corrected bromide space in parenterally supplemented infants.

Previously published data suggested that the faster rate of weight gain observed in parenterally supplemented neonates compared to their orally fed peers might be attributable to water retention rather than to more rapid tissue accretion. The present study was designed to test that hypothesis by observing changes in extracellular water, estimated as corrected bromide space (CBS). Ten neonates with a mean birthweight of 1,250 gm (range, 800 to 1,980 gm) and a mean gestational age of 31 weeks (range, 24 to 38 weeks) were randomly assigned to a 67 cal/dl formula feeding or an oral 100 cal/dl formula feeding supplemented parenterally with dextrose and amino acids. CBS was estimated within 19 hours of birth and between the 7th and 28th postnatal days. Mean total daily water and protein intakes during the intervening period were similar for orally fed and supplemented neonates, but the latter took significantly less orally and received more parenterally. CBS increased in all but one of the supplemented neonates whereas two of four orally fed babies had decreasing values and one had stable values. Shorter times before regaining birthweight, faster rates of weight gain, and lower arterial pH were associated with larger CBS as well as with parenteral supplementation. These data suggest that parenteral supplementation may result in water retention and/or shifts from the intracellular to the extracellular space. Previously reported earlier and greater mean daily weight gains in supplemented babies may be related to water accumulation rather than tissue accretion, but definitive conclusions must await further studies, including concomitant estimates of total and extracellular body water.

Neonatal paroxysmal supraventricular tachycardia with hydrops.

A critically ill infant with paroxysmal supraventricular tachycardia and hydrops fetalis responded well to aggressive management. Care must be taken to avoid digitalis toxicity. Procaine amide or quinidine are effective alternate therapies.

Regional neonatal transport: impact of an integrated community/center system.

In the face of increasing neonatal referrals from a large geographic region, community hospital resources was recruited and coordinated with regional center resources to facilitate "community-based" neonatal transport. All transport requests were first "triaged" by an attending neonatologist. Discriminant analysis was used to assess the impact of resource allocation decisions. Decisions regarding allocation of resources to an individual transport generally reflected geographic distance to be traveled, size of delivery service at referring hospital, and apparent degree of illness. Physicians participation in transports was reduced from 95% to 15% of the trips. The incorporation of community-based transport resources and nonphysician transport teams into a coordinated triage and transport process with existing center-based resources did not adversely affect neonatal survival. Capacity of the transport system was enhanced with these reallocations.

28-day survival rates of 6676 neonates with birth weights of 1250 grams or less.

Survival rates specific for birth weight, gestational age, sex, and race are described for 6676 inborn neonates who weighed less than 1251 g at birth and were born during 1986 through 1987. Overall 28-day survival increased with gestational age and birth weight, from 36.5% at 24 weeks' gestation to 89.9% at 29 weeks' gestation, or from 30.0% for neonates of 500 through 599 g birth weight to 91.3% for neonates of 1200 through 1250 g. The expected birth weight-specific survival advantage for female neonates and black neonates diminished when the data were controlled for gestational age, showing that certain previously reported survival advantages are based on lower birth weight for a given gestational age. Multivariate analysis showed that all tested variables were significant predictors for survival, in order of descending significance: gestational age and birth weight, sex, race, single birth, and small-for-gestational-age status. The powerful effect of gestational age on survival highlights the need for an accurate neonatal tool to assess the gestational age of very low birth weight neonates after birth.

Variability in 28-day outcomes for very low birth weight infants: an analysis of 11 neonatal intensive care units.

A retrospective study of all infants weighing 701 to 1,500 g born at 11 neonatal intensive care centers during 1983 and 1984 was performed to determine whether two specific 28-day outcomes, survival and survival without the need for supplemental oxygen, varied among the centers. Survival without the need for supplemental oxygen was chosen as a reflection of infants surviving without chronic lung disease. There were 1,776 live-born infants delivered during the 2-year study period. Of these infants, 85% (1,512) survived 28 days, a range of 80% to 92% at the individual centers. A total of 60% (1,056) of the infants were alive without supplemental oxygen on day 28, a range of 51% to 70% at the individual centers. Multivariate analysis demonstrated that both survival on day 28 (chi 2 = 23.9, P less than .01) and survival without supplemental oxygen on day 28 (chi 2 = 44.2, P less than .0001) varied significantly among centers after the effects of birth weight, gender, and race were taken into account. Female gender, nonwhite race, and increased birth weight were factors associated with improved rates of survival and survival without supplemental oxygen. The magnitude of outcome variation among centers was estimated by using the logistic regression models to predict what the outcomes would be if each center were to treat a standardized population consisting of all 1,776 study infants.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of amniography on amniotic fluid L/S ratio.

This report provides data indicating that the water-soluble dye combination commonly used in amniography raises the amniotic fluid lecithin/sphingomyelin ratio.

Black-white differences in newborn anthropometric measurements.

The mean birth weight of black infants is consistently less than that of white infants. In 1518 low-income multiparous women, the mean difference in singleton births was 171 g, of which 38 g was partitioned to preterm births and another 35 g reflected lower gestational ages in term births. A series of regression analyses were used to determine the effect of black race on various newborn measurements in 1205 term newborns, adjusting for other known risk factors. In this model, black race accounted for a mean decrease of 148 g in weight and 0.52 cm in length. There were also significant decreases in mean head (0.44 cm), chest (0.66 cm), and abdominal (0.56 cm) circumferences. Arm and leg lengths were not different, but black arm circumferences (0.14 cm) were significantly larger. Triceps and thigh skin fold measurements were not statistically different, but black subscapular skin fold values were significantly smaller (0.17 mm). The ponderal index in blacks was significantly less than in whites. These data suggest that in this population, intrinsic and/or extrinsic factors associated with race account for most smaller black newborn measurements and for much of the racial difference in birth weight.

Intraventricular haemorrhage and the renin-angiotensin-aldosterone system in very low birthweight infants.

Blood volume, plasma renin activity (PRA) and urine aldosterone excretion (UAE) were measured in ten very low birthweight infants who had a Grade 3 or 4 intraventricular haemorrhage (IVH) during the first 2 days after birth. Mean (range) birthweight was 950 (630-1500) g and gestational age was 27 (23-31) weeks. Nine infants were receiving assisted ventilation and one was breathing spontaneously. Eight IVH occurred on the first postnatal day and two on the second; seven were symptomatic and three asymptomatic. PRA was significantly higher than control values on Day 1 only; median 244 (range 91-654) ng/ml per h vs. 64 (4-259) ng/ml per h (P less than 0.01). Infants with symptomatic IVH in the preceding 8 h (n = 6) all had PRA greater than 300 ng/ml per h; none of these infants had received transfusions or volume expansion between IVH and PRA measurement. PRA was less than 100 ng/ml per h in the three infants with asymptomatic IVH and one infant with greater than 24 h interval between IVH and PRA measurement; three of these four had received transfusions prior to PRA measurement. UAE was not significantly different from control values on either Day 1 or Day 2. Blood volume at 22 +/- 3 h postnatal age ranged from 75 to 107 ml/kg. There was an inverse logarithmic correlation between PRA and blood volume (r = 0.883; P less than 0.005), with PRA values exceeding 300 ng/ml per h when blood volume was less than 90 ml/kg. UAE did not correlate with either PRA or blood volume.(ABSTRACT TRUNCATED AT 250 WORDS)

Control of infection due to Klebsiella pneumoniae in an intensive care nursery.

Because of an increased incidence of necrotizing enterocolitis (NEC) temporally related to Klebsiella pneumoniae colonization noted in several infants, a study was undertaken to identify the source and to eradicate the infection. Twenty infants in the neonatal intensive care unit (NICU) and 51 in the well-baby nursery were prospectively studied. Cultures were done on all infants. In addition, cultures were done on all employees and parents who regularly visited. Our results showed an increased incidence of infection during this period--8.3% as compared with 4.79% overall. Colonization with K pneumoniae was eradicated, at least temporarily, by establishing a cohort system in both the NICU and the well-baby nursery and by the administration of antibiotics to all infants in these nurseries. Colonized parents and employees were also treated. Follow-up cultures showed clearing of Klebsiella, and the cohort system was abolished. Serotyping of all affected infants later showed that different strains were present, making it unlikely that there was a common source for the Klebsiella. (Initially the source of infection had been thought to be a mother whose premature triplets were colonized. We feel that the eradication of this organism and the subsequent decline in NEC was enhanced by the combination of cohorting and handwashing. The selected use of antibiotics may have prevented an extension of the outbreak, but this could not be proven.

Association of patent ductus arteriosus and phototherapy in infants weighing less than 1000 grams.

To determine the relationship of phototherapy and patent ductus arteriosus, we analyzed prospectively collected data on 295 infants with birth weight of 501 to 999 gm admitted from 1984 through 1988. Seventy-four percent were evaluated by an imaging study to aid in the detection of a silent patent ductus arteriosus. Overall incidence of patent ductus arteriosus in the study population was 63%. Infants who received phototherapy (n = 128) had an increased incidence of patent ductus arteriosus compared with those who did not receive phototherapy (76% vs 53%). There was an association of patent ductus arteriosus and phototherapy (p < 0.05) when we analyzed the data with a stepwise regression model that controlled for the effects of gestational age, birth weight, gender, race, diagnosis of hyaline membrane disease, mechanical ventilation, patent ductus arteriosus imaging studies, prophylactic indomethacin, peak total and indirect bilirubin values, and the occurrence of abnormal serum sodium values. We conclude that the use of phototherapy is associated with an increased incidence of patent ductus arteriosus in extremely low birth weight infants.

Effects of position changes on transcutaneous carbon dioxide tension in neonates with respiratory distress.

Routine neonatal care includes frequent position changes. Recent research has concluded that positions other than supine may result in beneficial physiologic responses. Specifically, several studies suggest that neonates may ventilate more effectively in a prone rather than in a supine position. This study tested the hypothesis that transcutaneous carbon dioxide tension (TcPCO2) would be lower in the prone than in the supine position in neonates with respiratory distress. Fourteen ventilated infants were studied. TcPCO2 was measured and recorded in prone, supine, and right-side-lying positions for each subject. There were no statistically significant differences in mean TcPCO2 values between the three positions (F = .45; df 2,39; P = .64). The relationship between TcPCO2 and PaCO2 values was stable (r = .88) during the studies. The results indicate that changing a neonate's position does not significantly alter transcutaneous carbon dioxide tension.

Neonatal transcutaneous bilirubinometry.

The authors present data supporting the conclusion that the transcutaneous bilirubin index may be a valuable tool to help distinguish term babies with a total serum bilirubin value less than 13 mg/dl from those with higher levels and that it serves as a valuable screening device to decrease the number of unnecessary total serum bilirubin tests. Also examined are clinical guidelines and limitations of the device.

Transcutaneous oxygen (tcPO2) measurements as an aid to fluid therapy in necrotizing enterocolitis.

Impaired peripheral perfusion is a major problem in necrotizing enterocolitis with delayed recognition and definite documentation being primary factors. While blood pressure and other clinical measurements may improperly estimate the severity of the problem, changes in transcutaneous oxygen measurements and their relationship to arterial oxygen (the tcPO2/PaO2 ratio) potentially afford a sensitive measurement of peripheral perfusion. Experience in our unit confirms a close relationship between tcPO2/ and PaO2 being 0.97 +/- 0.04 (SE). Ten infants with birth weights of 640 to 1380 g, who subsequently developed necrotizing enterocolitis, had strikingly lower ratios initially (0.00, 0.00, 0.00, 0.17, 0.21, 0.43, 0.44, 0.48, and 0.56). Use of the tcPO2/PaO2 ratio to monitor fluid therapy was related to outcome, suggesting that this ratio is important in managing necrotizing enterocolitis.