Early discharge of low birthweight infants as a hospital policy.

All 123 infants with birthweights less than or equal to 2000 g born at a private institution between February 1, 1987, and January 31, 1988, were eligible for early discharge if they met the following criteria: weight about 1800 g, medically stable, feeding well by nipple, satisfactory weight gain, thermostability, and parents and home prepared. Forty-one of 48 (85.4%) infants who satisfied these criteria were discharged at birthweights less than 2100 g. None of the 35 infants for whom follow-up was possible were rehospitalized, had a serious illness, or died as a result of the policy. The policy was universally accepted by the staff. Such a policy has the potential to unite babies and families sooner, promote the mental health of the families, save medical dollars, and make the medical resources of newborn intensive care units available for critically ill infants.

Isoimmune neonatal neutropenia.

An unselected population of newborn infants at a tertiary perinatal center was the subject of an investigation of isoimmune neonatal neutropenia (INN) to determine the incidence of the disorder and further characterize its clinical and immunologic aspects. We screened 1465 consecutively born infants for neutropenia on the first day of life, and evaluated those with neutropenia for the presence of antineutrophil antibodies utilizing EDTA-microagglutination and indirect immunofluorescence. Of the 16 infants with persistent neutropenia, 3 were confirmed to have INN, representing 2/1000 live births and 1.5% of special care nursery admissions during the period. INN is not a rare disorder and should be considered in the evaluation of all infants with neutropenia, with or without infection. Our rapidly expanding knowledge of the neutrophil-specific antigen system is refining our ability to diagnose and treat immune neutropenias.

Maternal and fetal metabolic effects of prolonged ritodrine infusion.

To investigate metabolic and endocrine changes in the fetus during prolonged maternal tocolysis with beta sympathomimetic drugs, ritodrine hydrochloride (2.1 micrograms/kg per minute) was infused into pregnant sheep near term. Confirming earlier studies, maternal plasma metabolite and hormone levels changed greatly during the first six to eight hours of infusion. Changes in the fetus paralleled these closely: glucose, lactate, and insulin increased sharply, but glucagon and alpha-amino acid nitrogen decreased. After this, most maternal and fetal plasma metabolite and hormone levels returned to the normal range and were unchanged by infusion for 72 to 96 hours. Fetal lactate levels, however, remained elevated. Similar changes occurred during interrupted maternal infusions of ritodrine. Prolonged infusion of ritodrine leads to diminished responsiveness in beta-adrenergic mechanisms regulating maternal plasma metabolite and hormone levels. Comparable unresponsiveness of fetal beta-adrenergic mechanisms, though less certain, could increase hazards during delivery and adaptation to postnatal life.

A computerized system for the identification of alloimmune neutropenia in neonates.

In an attempt to determine the incidence of alloimmune neonatal neutropenia, a systematic study was initiated during a period of six months. Complete blood count, differential and absolute neutrophil count of all the newborns were determined to identify the newborns with neutropenia and those with persistent neutropenia were evaluated for the presence of maternal neutrophil antibodies. This resulted in the design and use of a computerized system which was successfully employed to identify several neonates born with this disorder. The system includes a main program and eight functional options, and is operated under a secret authority code so that patients' data are accessible only to the investigators. The major functional options are: create, display, update and delete a record for the newborn; display most recent neutropenic babies; search all records and display name and ID number; search all records for a given year and display data; and perform statistics. The statistical analysis includes the total number of babies, both normal and those with neutropenia, the total number of babies with neutropenia and with/without sepsis, and those with persistent neutropenia. Also included are the hematological data consisting of complete blood count and differential of all of the newborns. Several possibilities exist to expand and extend the program for additional research-related purposes.

Newborn screening for ABO hemolytic disease.

Confusion still exists regarding the true incidence of ABO hemolytic disease and the significance of the various laboratory investigations commonly employed in its evaluation. With such imprecision in diagnosis, early hospital discharge of newborns can be a potential problem. To evaluate the usefulness of more extensive screening than commonly employed and to identify possible indicators of severity, a pilot study of cord blood screening was undertaken. In the study, 1391 cord blood specimens were tested for type, Rh, direct antiglobulin test (DAT), indirect Coombs, and total and indirect bilirubin. Of the specimens, 53.3 percent were type A, B, or AB, and 19.3 percent of both A and B infants and 7 percent of AB infants had immune antibodies in their sera. DAT was neither diagnostic nor predictive of severity. DAT was negative in 48 percent of infants with serum antibody and did not correlate with cord blood or peak serum bilirubin levels. The cord blood bilirubin also was not diagnostic of hemolytic disease but was moderately predictive of peak bilirubin levels. The data do not support the use of any routine screening tests in the management of ABO hemolytic disease.

Renal failure and other serious sequelae of epinephrine toxicity in neonates.

Epinephrine has numerous potent pharmacologic actions with protean manifestations. We have described a patient in whom inadvertent intra-aortic administration of a large dose of racemic epinephrine produced serious adverse effects, including hypertension, acidemia, tachycardia, and protracted but reversible renal failure. In view of the ubiquitous use of epinephrine in neonatal intensive care, we hope that this report heightens awareness of its more serious and potentially fatal toxic effects.

Hyperinsulinemia and decreased surfactant in fetal rabbits.

To isolate and demonstrate the effect of insulin on pulmonary surfactant in vivo, islet cell hyperplasia and hyperinsulinemia were produced in fetal rabbits by the litter reduction technique without concomitant hormonal or metabolic changes in mother or fetus. This produced fetuses which were heavier than controls (37.1 vs. 31.5 g), with two-fold higher insulin levels (48.1 vs. 24.3 microU/ml). The fetal weight correlated directly with the insulin level, while the L/S ratio was found to correlate inversely with the insulin level. This inhibitory effect may be mediated by any of several mechanisms which await further investigation.

Incidence of neutrophil antigens on human cord neutrophils.

Neutrophils isolated from cord blood of healthy newborns (33 blacks and 21 whites) were investigated by EDTA-microagglutination for their expression of neutrophil specific antigens that have been associated with isoimmune neonatal or autoimmune neutropenia. Equal volumes of various neutrophil antisera (2 microliter) and cord neutrophils (3-5 X 10(6)/ml) were mixed in tissue typing microplates under oil and were incubated at room temperature for 6-8 hr, following which the degree of agglutination was noted. Our data revealed that all the currently recognized neutrophil antigens are readily demonstrable by antineutrophil antibodies in cord blood, (NA1, 52-54%; NA2, 81-85%; NB1, 95-96%; NC1, 90%; 9A, 29-30%) suggesting that neutrophil antigens are fully expressed at birth.

Diurnal and other cyclic variations in human fetal heart rate near term.

In 10 healthy women near term, fetal heart rate, as monitored from an abdominal electrocardiogram, and its variation were analyzed over 24 hours. During the daytime, this was combined with real-time scanning for fetal breathing and movements. There was an episodic change in high and low pulse (R-R) interval variation with a mean cycle length of 92 minutes. The changes in cycle length were large; around midnight, episodes of high variation lasted up to 6 hours. Episodes of high variation coincided with greater fetal movement (measured only in daytime). Neither low nor high episodes were consistently related to fetal breathing. Both fetal heart rate and its variability showed a diurnal variation, by 11% and 50%, respectively; these were not statistically related. There was a particularly large change in pulse interval variation with peak values around midnight; concomitantly, there was a diurnal variation in the incidence of accelerations of defined size. The implications of these findings are discussed.

Unilateral pulmonary interstitial emphysema: a surgical approach to treatment.

Pulmonary interstitial emphysema is a condition that has become a significant problem chiefly as a complication of mechanical ventilation of the newborn. In its severe forms, it may compromise ventilation and restrict pulmonary blood flow to the degree that it becomes a significant cause of mortality. When its occurrence is unilateral, or predominantly so, it becomes more amenable to therapy. A number of different approaches have been described, especially for milder forms of the disease, but none has proved entirely satisfactory. A surgical approach has been used in four patients with severe unilateral pulmonary interstitial emphysema complicating ventilator therapy for hyaline membrane disease. The technique was successful in three of the four infants. The technique was successful in three of the for infants. An illustrative case is described, as well as the selective criteria for application of the technique.

Numerical analysis of the human fetal heart rate: modulation by breathing and movement.

Signal averaging has been used to identify the modulation of fetal heart periods (pulse intervals) by body movements and breathing, identified by a real-time ultrasound scan in normal pregnancies of 37 to 39 weeks. Accelerations were associated with fetal movements and were accompanied by arrest of fetal breathing and a decrease in beat-to-beat variation. They were commonly succeeded by decelerations, with an increase in beat-to-beat variation, within 15 to 20 seconds. In the absence of gross accelerations or decelerations, fetal breathing was associated with a high-frequency modulation of heart periods, measureable as a small increase in beat-to-beat variation. There was clustering of this characteristic pattern around and within fetal breathing episodes, which suggests that it may be a more sensitive index of breathing than visual identification with ultrasound. The conclusions are: (1) the grosser episodic changes in fetal heart rate are associated with the regular repetition of a pattern of accelerations and movements repeated at intervals less than 2 minutes; (2) fetal breathing episodes are independent of these gross changes; (3) beat-to-beat variation alters in a complex fashion and in different directions in association with physiologic changes.