Effects of neurodevelopmental risk factors on brainstem maturation in premature infants.

BACKGROUND: Interpeak latencies (IPL), as measured by the auditory brainstem-evoked responses (ABR) test, represent the conduction time, and therefore the maturation of the brainstem auditory pathway. We aimed to study the effect of various risk factors for the neurodevelopmental delay on the conduction time in the auditory pathway among normal hearing premature infants, at term postmenstrual age (PMA). METHODS: Retrospective analysis of 239 premature infants (gestational age 32.5 ± 2.1 weeks, birth weight 1827 ± 483 g). Interpeak latencies, demographic data, and risk factors were recorded. RESULTS: Sex, PMA at ABR test, being small for gestational age (SGA), intraventricular hemorrhage (IVH) or periventricular leukomalacia (PVL), and days of invasive ventilation were found to significantly affect the IPL's in the auditory pathway in a univariate analysis. Multivariable regression analysis revealed that male sex and less advanced PMA at the examination were independent factors associated with prolonged IPL's, while bronchopulmonary dysplasia, IVH or PVL and being SGA shortened the IPL's. Non-invasive mechanical ventilation, did not affect the caudal part of the auditory pathway, despite its high noise level. CONCLUSIONS: Among various risk factors for the neurodevelopmental delay, male sex was associated with delayed, while IVH or PVL, BPD and SGA could be associated with accelerated auditory brainstem maturation. IMPACT: Auditory brainstem-evoked response (ABR) test, among normal hearing infants, can serve as a clinical tool to assess brainstem auditory maturation. Different neurodevelopmental risk factors could have different effects on the maturity of the auditory pathway. Male sex is significantly associated with prolonged interpeak latencies (IPL) among preterm and term infants, while intraventricular hemorrhage or periventricular leukomalacia, bronchopulmonary dysplasia, and being small for gestation age may be associated with shortened IPL The corrected age at ABR testing is of significance, among preterm and term infants.

Administration of 100% oxygen does not hasten resolution of symptomatic spontaneous pneumothorax in neonates.

OBJECTIVE: To compare the effectiveness of 100% oxygen therapy vs oxygen treatment with targeted pulse oximetry in the management of symptomatic small to moderate spontaneous pneumothorax (SP). In total, 100% oxygen treatment for SP has been a common practice in neonatology, albeit there is little evidence to validate its efficacy. STUDY DESIGN: A retrospective chart review of 83 neonatal records with the diagnosis of pneumothorax was conducted. Infants <35 weeks gestation, those with large pneumothoraces requiring chest tube drainage and/or ventilatory support were excluded. Data gathered included demographics, vital signs, treatment information and clinical indicators of resolution of symptoms. RESULT: In total, 45 neonates with SP were included in the study. Groups were similar for gestational age, birth weight, Apgar scores, gravidity, parity, gender, race, pneumothorax size and location. Patients in the 100% oxygen therapy group received a significantly longer oxygen treatment (21.3 vs 8 h, P < 0.001), required longer intravenous fluid treatment (48.6 ± 29.9 vs 31.3 ± 18.8 h, P = 0.03) and were delayed in reaching full feeds (44.1 ± 25.7 vs 29.5 ± 18.8 h, P = 0.03) compared with the oxygen-targeted treatment group. Time to first oral feeding, time to resolution of tachypnea and length of stay were similar in both groups. CONCLUSION: There are no clinically significant advantages to using 100% oxygen in the treatment of symptomatic small to moderate SP. In fact, it may result in longer exposure to unnecessary oxygen treatment and toxicity. Oxygen should be reserved for those who are hypoxic and adjusted to comply with accepted saturation levels in neonates.

Inhibition of cerebellar granule cell turning by alcohol.

Ectopic neurons are often found in the brains of fetal alcohol spectrum disorders (FASD) and fetal alcohol syndrome (FAS) patients, suggesting that alcohol exposure impairs neuronal cell migration. Although it has been reported that alcohol decreases the speed of neuronal cell migration, little is known about whether alcohol also affects the turning of neurons. Here we show that ethanol exposure inhibits the turning of cerebellar granule cells in vivo and in vitro. First, in vivo studies using P10 mice demonstrated that a single intraperitoneal injection of ethanol not only reduces the number of turning granule cells but also alters the mode of turning at the EGL-ML border of the cerebellum. Second, in vitro analysis using microexplant cultures of P0-P3 mouse cerebella revealed that ethanol directly reduces the frequency of spontaneous granule cell turning in a dose-dependent manner. Third, the action of ethanol on the frequency of granule cell turning was significantly ameliorated by stimulating Ca(2+) and cGMP signaling or by inhibiting cAMP signaling. Taken together, these results indicate that ethanol affects the frequency and mode of cerebellar granule cell turning through alteration of the Ca(2+) and cyclic nucleotide signaling pathways, suggesting that the abnormal allocation of neurons found in the brains of FASD and FSA patients results, at least in part, from impaired turning of immature neurons by alcohol.

Decreased neonatal tibial bone ultrasound velocity in term infants born after breech presentation.

OBJECTIVE: Fetuses found to be in the breech presentation have limited motion of their lower limbs. The aim of this study was to test the hypothesis that bone speed of sound (SOS) would be lower in infants born after breech presentation than in those born after vertex presentation. STUDY DESIGN: We studied 127 singleton, appropriate for gestational age, term infants delivered by a scheduled cesarean delivery at approximately 38 weeks of gestation because of breech presentation or repeat elective cesarean section with vertex presentation. We used the Sunlight Omnisense 7000p device to measure axially transmitted SOS of the right tibia within the first 96 h of life. RESULT: Fifty-three infants studied (42%) were born by cesarean section after breech presentation compared to 74 vertex controls. Bone SOS was significantly lower in the breech presentation group, even after taking into account the effect of gender and parity (as well as gestational age at birth and birth weight). CONCLUSION: Bone SOS is lower in infants born after breech presentation than in those born after vertex presentation. We speculate that limited motion of lower limbs in fetuses found to be in the breech presentation leads to a decrease in bone mineralization and strength.

Nosocomial cutaneous abscesses in septic infants.

OBJECTIVE: To retrospectively study the epidemiology of nosocomial cutaneous abscesses in 46 consecutive septic infants. RESULTS: Ten infants had one abscess or more. Surviving infants with abscesses had a longer duration of bacteraemia, which disappeared within 24 hours of drainage. CONCLUSION: Infants with persistent bacteraemia should be examined regularly for the presence of abscesses.

Double catheter technique for misdirected umbilical vein catheter.

We studied the success rate of the double catheter technique during umbilical vein catheter placement in 42 patients with a misdirected umbilical vein catheter. The misdirected catheter was left in place, and an additional catheter was inserted. X-ray films confirmed that successful placement was achieved in 50% of infants without significant adverse effects.