Maternal dietary docosahexanoic acid content affects the rat pup auditory system.

Previous studies of the effects of dietary docosahexanoic acid (DHA), 22:6n3, on neurodevelopment have focused mainly on visual-evoked potentials and indices of visual activity, measures that may be confounded by effects on the retina rather than on neural pathways. We investigated the effect of pre- and postnatal maternal dietary DHA content on auditory brainstem conduction times (ABCTs), the appearance of the auditory startle reflex (ASR), and 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) activity in brainstem homogenates. Timed pregnant dams were fed, beginning on day 2 of gestation and throughout lactation, a purified diet containing one of three levels of DHA (0, 1, or 3% of total fatty acids, or 0, 0.4 or 1.2% of total energy). On postnatal day (PND) 3, pups were randomly crossfostered within diet groups to minimize litter effects and culled to 10 per litter. Cerebrums and milk from culled pups stomachs were collected for lipid analysis. The timing of appearance of the ASR was determined between PND 10 through 14 and ABCTs were measured in pups on PND 24 and 31. Pups were sacrificed on PND 31 and cerebrums were removed. In each of two replicated studies, pups in the 1% DHA group weighed significantly less on PND 3 and they gained significantly less weight from PND 3 to 31 compared with pups in the 0 or 3% groups (p<0.01). The auditory studies were not conducted on the 1% DHA group since measures of auditory function are in part a function of somatic growth. The tissue fatty acid data for the 1% DHA group did not show unexpected findings. Higher dietary DHA was reflected in milk and pup cerebrums, and levels of arachidonic acid were inversely related to levels of DHA. In the pups of dams fed diets containing 3% versus 0% DHA, the ASR appeared significantly later (p<0.001) and the ABCTs were longer (p<0.05) on PND 31. CNPase activity levels were not different between the 0 and 3% DHA groups. This study demonstrated that the auditory brainstem response is sensitive for identifying effects of diet on neurodevelopment, and that diets supplemented with high levels of DHA may exert a negative influence on central nervous system development, potentially through effects on myelin. This study suggests the need for further studies of pre- and postnatal long chain polyunsaturated fatty acid dietary supplementation.

Neonatal intubation performance: room for improvement in tertiary neonatal intensive care units.

OBJECTIVE: To describe neonatal tracheal intubation (TI) performance across five neonatal intensive care units. METHODS: This prospective descriptive study was conducted at five level III neonatal intensive care units (NICU) between July 2010 and July 2011. TI performance data were collected using a standardized data collection instrument (provider, procedure, and patient characteristics) and analyzed using descriptive and inferential statistics. The primary outcome of interest was procedural success rate defined as a tube placed in the airway between the vocal cords that could be used to provide ventilation. RESULTS: Forty-four percent of 455 TI attempts (203 patients) were successful. Attending physicians and 3rd year neonatal fellows had the highest success rates; 72.2% and 70%, respectively. Pediatric residents had the lowest success rate (20.3%). The median duration of attempts was 30s for residents, 25s for fellows, and 20s for neonatal attending physicians. The most common reasons cited for failure were inability to visualize the vocal cords (25%), patient decompensation (desaturation/bradycardia, 41%) and esophageal TI (19%). The duration of all TI attempts ranged from 5s to 180s and there was no difference between successful and failed attempts. Impending respiratory failure (46.5%) was the most common indication for TI. Patient factors (weight, gestational age, or number of previous TI attempts) were not associated with TI success. CONCLUSIONS: Overall TI procedure success rates were poor. Providers with advanced training were more likely to be successful. Patient factors were not associated with TI success.