Auditory brain-stem evoked potentials to clicks at different presentation rates: estimating maturation of pre-term and full-term neonates.

Auditory brain-stem evoked potentials ABEPs were recorded from 57 neonates ranging in gestational age between 27 and 43 weeks. Averages and standard deviations of I, III and V peak latencies, I-V, I-III and III-V inter-peak latency differences (IPLDs), for 10/sec and 55/sec clicks were calculated for each age group. An additional measure, the net effect of increasing stimulus rate (ISR), was calculated by subtracting 10/sec measures from their 55/sec counterparts. Correlations between ABEP measures and subject age were determined. The results of this study demonstrate a significant correlation between gestational age and electrophysiological measures of peripheral, as well as central, conduction: an inverse correlation between age and peak latencies as well as IPLDs. The slope of this correlation was steeper for the higher stimulus rate. The slope of 55/sec measures vs. age was the sum of the respective slopes of 10/sec measures and of ISR. The maturation of 10/sec measures may reflect white matter development, while ISR changes with gestational age represent maturation of synaptic efficacy. Thus, the maturation of 55/sec measures reflect the combined maturation of nerve conduction velocity and synaptic efficacy along the neonatal auditory nerve and brain-stem. This differential evaluation may enable more accurate determination of developmental age of neonates, with respect to total maturation as well as its constituents.

Intralipid effects on preterm neonate serum: chemoattractant and opsonizing capacities.

The effects of Intralipid (IL) administration of preterm infants have been investigated. For this purpose, adult neutrophils were stimulated by infant sera collected before and after IL treatment. A definite decrease (p less than 0.0005) in chemoattractant capacity of zymosan-activated serum was observed after IL. On the other hand, no difference in the opsinizing abilities of untreated versus treated sera could be demonstrated by measuring the chemiluminescence responses to serum-opsonized zymosan. This study emphasized the need of caution in the use of IL treatment for preterm infants.

Clinical assessment of hip instability in the newborn by an orthopedic surgeon and a pediatrician.

The aim of this study was to improve the rate of detection of hip instability in the neonate. Over a period of 3 years, a pediatric orthopedic surgeon and a neonatal pediatrician both examined 12,891 neonates. During the fourth year, 5,087 newborns were examined by a pediatrician only. Each examiner, working independently, found that 51 babies had neonatal hip instability. In an additional 25 babies, one examiner failed to detect this instability on initial examination. Finally, 36 babies judged to have stable hips at birth later gave cause for orthopedic treatment. These findings strongly suggest that screening should not be restricted to the neonate but should involve several sequential examinations.

Bilirubin removal from a jaundiced premature infant by resin hemoperfusion.

To summarize the results: Bilirubin removal by hemoperfusion was successfully performed for the first time on a premature infant. The hemoperfusion caused no adverse effects on the clinical state of the infant. The bilirubin removed in 90 min--13 mg--indicates the existence of a large extravascular pool. Hemoperfusion is suggested for bilirubin removal from newborn babies, reducing the need for blood exchange with bank blood.

Neonatal septicemia caused by coagulase-negative staphylococci.

We report our experience with coagulase-negative staphylococcal infection over a period of 1 year. The incidence of coagulase-negative staphylococcus septicemia was 4.25% (13 newborn infants) of the 306 admissions to our Neonatal Intensive Care Unit. Ten patients (76.9%) were premature infants. Four infants in our series were less than 48 h of age. Two of these were presumably born with the infection. Six infants had involvement of the lungs. The strains of coagulase-negative staphylococci cultured from all cases of neonatal septicemia were sensitive to cephalothin, but were considerably less sensitive to the currently used antibiotic combinations. Our observations indicate that coagulase-negative staphylococci must be suspected in early or late neonatal sepsis, and that early antibiotic treatment by cephalothin may prevent morbidity.

Normal plasma-urine osmolality relationship in preterm infants on positive pressure mechanical ventilation.

Mechanical ventilation with positive pressure has been implicated in the inappropriate release of vasopressin. To examine whether such a phenomenon occurs in infancy, 26 preterm neonates with Respiratory Distress Syndrome were studied. Simultaneous urine and plasma were collected for osmolality determination during mechanical ventilation with positive end expiratory pressure of 4-8 cmH2O. Results were plotted onto our previously described nomogram. The data show normal distribution of plasma to urine osmolality ratio in 25 out of 26 infants. These results do not support the common belief that positive pressure mechanical ventilation in the newborn with RDS provokes inappropriate secretion of vasopressin.

The use of calcium gluconate prior to verapamil in infants with paroxysmal supraventricular tachycardia.

Verapamil is a useful drug for treating supraventricular tachycardia; however, severe side effects occasionally have been reported in infants. We describe here our experience with the use of a 10 percent solution of intravenous calcium gluconate prior to the use of verapamil in infants with paroxysmal supraventricular tachycardia. In all the attacks verapamil converted the supraventricular tachycardia to sinus rhythm. We feel that calcium gluconate injected previous to verapamil can avoid the negative inotropic effects without interfering with the antiarrhythmic properties of verapamil.

Plasma and urine osmolality in full-term and pre-term infants.

The purpose of the present study was to determine the normal relationship of urine and plasma osmolality in pre-term and full-term infants. Twenty-nine full-term and 35 pre-term babies were studied during the first week of life. Random simultaneous urine and plasma samples were measured for osmolality. Statistical analysis defined the normal relationship of plasma to urine osmolality. This suggests an osmotic threshold of 282 mOsm/kg and 291 mOsm/kg for full-term and pre-term babies, respectively. These values are different from the 285-290 mOsm/kg of adolescents and adults. The nomograms provided may serve as a useful aid in the bedside diagnosis of dysfunctional secretion of vasopressin.

Resin hemoperfusion for unconjugated bilirubin removal.

The application of an anionic macroreticular ion exchange resin, coated with a thin cross-linked albumin layer, as a hemoperfusion device for the removal of unconjugated bilirubin from the blood of hyperbilirubinemic newborn babies is reviewed. In vivo hemoperfusion runs with hyperbilirubinemic animal models - either by a choledocho-suprarenal vein shunt or by direct infusion of bilirubin into the vein - showed that a 40-ml resin column can remove some 20 mg bilirubin in 3 h. Hemoperfusion of female 8-14 kg baboons showed no significant effect of the column on blood chemistry and coagulation factors and repeated runs had no ill effects.

Asplenia syndrome. Report of two cases.

Two babies with asplenia syndrome are described. Both presented with the severe cardiovascular anomalies found in this syndrome and had Howell-Jolly bodies in peripheral blood smears. The chest X-rays showed dextrocardia, decreased pulmonary circulation and a horizontal symmetrical liver, and were helpful in the clinical diagnosis. Additional findings at autopsy included a mobile cecum and bilateral trilobed lungs with bilateral eparterial bronchi.

Acute appendicitis located in a scrotal hernia of a premature infant.

A premature infant is presented with acute appendicitis in a scrotal hernia causing localization of the inflammatory signs to the scrotum, and relatively early operation.

Refraction in premature babies: a prospective study.

Refraction in 67 premature babies was examined and followed during seven years. There was continuous changing of refraction towards emmetropia in all refraction groups. Fifty-four percent of myopic eyes remained myopic at the age of seven years but in all the eyes myopia was of lower degree than at birth. In our series there was no relationship between myopia and RLF.