Eliana Arbel

Effect of gentamicin on the auditory brainstem evoked response in term infants: a preliminary report.

ABSTRACT: Seven essentially healthy term infants who received gentamicin starting on the 1st day of life for prolonged rupture of membranes and maternal fever were compared with nine healthy term infants to determine whether this drug induces alterations in the auditory pathway. The auditory pathway was studied on the 3rd day of life by analyzing brainstem auditory evoked potentials elicited by a click stimulus presented at the infants ears. Latencies of components III and V, interval I–III, and interval I–V were significantly prolonged in the gentamicin group, indicating impairment of the central component of the auditory pathway. Peak and trough serum gentamicin levels all fell within the recommended therapeutic range. The study indicates that short course gentamicin therapy in healthy newborn infants can lead to abnormality of auditory function.

Predictive inability of cord zinc, magnesium and copper levels on the development of benign hyperbilirubinemia in the newborn

Cord serum concentrations of zinc, magnesium and copper were determined in 90 healthy term infants. The infants were divided by peak bilirubin values into an icteric group (peak bilirubin > 136 μmol/1) (n= 21) and a control group (peak bilirubin ≤ 136 μmol/)(n= 69). Mean cord serum zinc, magnesium and copper concentrations in the icteric group did not differ from those of the control group. Furthermore, no significant correlation was found between peak serum bilirubin concentrations and cord serum concentrations of these three elements. We conclude that cord serum concentrations of zinc, magnesium or copper are not useful in predicting which neonates will develop hyperbilirubinemia.

Preincubation with intravenous lipid emulsion reduces chemotactic motility of neutrophils in cord blood

Neutrophils from cord blood of healthy term infants were isolated and incubated for 30 min with varying concentrations of intravenous lipid emulsion (ILE) solution (4, 8, 20 mg/ml). In vitro assay of chemotaxis was performed after incubation for 120 min with endotoxin-activated serum (EAS). Neutrophil random motility was unchanged after ILE incubation yet chemotactic factor (EAS)-stimulated motility was significantly reduced in a dose-related pattern.

Transient neonatal hypothyroxinemia and the auditory brainstem evoked response.

Ten premature infants with low serum thyroxine levels (less than 84 nmol/L) were compared with 10 biochemically euthyroid infants to determine whether hypothyroxinemia in such infants can lead to alterations in the auditory pathway. The auditory pathway was studied between 6 and 11 wk of life by analyzing brainstem evoked potentials elicited by a 10/s, 75 dB above normal adult hearing level click stimulus presented at the infants ears. Peak latencies of components I, III, and V and interpeak latencies I-III, III-V, and I-V did not yield statistically significant differences between groups. The present study indicates that untreated neonatal hypothyroxinemia does not lead to abnormalities of auditory brainstem evoked response.

Brainstem Auditory Evoked Response in Newborns and Infants

Brainstem auditory evoked response studies were carried out on 105 neonates, with gestational ages ranging from 26 to 43 weeks. The mean chronologic and postconception ages of the subjects were 6.5 weeks and 40.6 weeks, respectively. Statistically significant relationships between brainstem auditory evoked response and gestational age, postconception age (gestational age plus chronologic age), and the 5-minute Apgar score, were demonstrated. Shortening of brainstem auditory evoked response as related to postconception age was demonstrated and this trend was statistically significant. However, of these factors a statistically significant shortening (maturation) of evoked response was demonstrated only in relation to postconception age. (J Child Neurol 2000;15:33-35).

Reducing blood transfusion requirements in preterm infants by a new device: a pilot study

Objective: To test a new device designed to salvage red blood cells (RBCs) from blood samples drawn from preterm infants, with the intent of decreasing blood loss and lowering the requirements for RBC transfusions.

Factors affecting plasma bilirubin in preterm infants ventilated for respiratory distress syndrome.

OBJECTIVE:To evaluate the contribution of various factors to plasma bilirubin level in preterm infants with a birth weight of <1500 gm in need of mechanical ventilation for respiratory distress syndrome (RDS) during their first week of life.METHODOLOGY:A total of 50 very low birth weight (<1500 gm) preterm infants consecutively admitted to the neonatal intensive care unit were studied. Plasma bilirubin levels were determined every 8 hours for the first week of life. Data relating to daily body weight, daily fluid intake, age at onset of gavage feeds, daily caloric intake, and grade of intraventricular hemorrhage (IVH) were collected. Data relating to mechanical ventilation were collected every 4 hours as follows: fractional inspired O2, arterial PO2, arterial PCO2, and mean airway pressure. An arterial/alveolar PO2 ratio and a corrected oxygenation index were computed for the first 2 days of life.A bilirubin index (BI), defined as the ratio of peak plasma bilirubin level to birth weight1/3, was used to study the association between bilirubin and the above variables. A BI was also used as a criterion for starting and discontinuing phototherapy. Multiple linear regression analysis was used to model BI.RESULTS:IVH (p < 0.0001), age at onset of gavage feeds (p < 0.003), oxygenation index (p < 0.007), and gestational age (p < 0.05) made a significant contribution to variations in BI (37.16%, 43.71%, 48.99%, and 53.33%, respectively).CONCLUSION: Hyperbilirubinemia in ventilated preterm infants with RDS is most likely multifactorial; entities quite distinct from RDS (such as nutrition and IVH) may significantly contribute to its variation.

Platelet counts in maternal and umbilical venous blood at the time of delivery

Platelet count in 38 paired maternal venous and umbilical venous specimens were determined at delivery. Umbilical values were significantly higher than simultaneous maternal values (p = 0.004), and a significant relationship was demonstrated between umbilical values and maternal values (r = 0.54, p = 0.0004). Associations between platelet counts and acid-base variables were found to be insignificant in the mother and the umbilical cord.