Neonatal Updates

McLanders ML, et al. The cognitive aids in medicine assessment tool (CMAT) applied to five neonatal resuscitation algorithms. J Perinatol. 2016.In many delivery rooms around the world, algorithms for neonatal resuscitation steps are posted on the walls. Do they help? Are they constructed to the best current standards? This paper reports an analysis of common algorithms, and the result is clear, there are serious limitations of all the available algorithms. Apart from a lack of clarity, and difficulty in using them during a real resuscitation, they are not even consistent with the standards on which they are supposedly based. Most end up on an infinite loop of administration of intravenous adrenaline, evaluation and re-administration of intravenous adrenaline. I hope the next step in the research of this group is to construct a better, clearer algorithm which does meet these standards. And then test whether it really helps resuscitation teams in the real world.

Logan JW, et al. Early postnatal illness severity scores predict neurodevelopmental impairments at 10 years of age in children born extremely preterm. J Perinatol. 2017. This study compares SNAP-II scores from babies in the ELGAN cohort and their neurodevelopmental outcomes at 10 years of age. Being very sick in your first 12 hours of life (SNAP-II more than 30, 23% of the subjects) increases the chances of lower scores on a range of neurocognitive tests. The differences are not enormous when expressed as the difference in the median z-scores (compared to population norms) but many are unlikely to be due to chance alone; many of the adjusted Odds Ratios show an increased Odds of the adverse outcome by a factor of around 1.6. There were also statistical associations with poorer social outcomes, and behavioural outcomes.

I don’t think that this necessarily means that the first 12 hours are critical for brain development, infants with higher early SNAP scores are more likely to have a range of other later complications also (such as necrotising enterocolitis), so the mechanisms behind this association are uncertain. Being very sick certainly is associated with an increased risk of a range of different outcomes, though.

Horne RS, et al. The Longitudinal Effects of Persistent Apnea on Cerebral Oxygenation in Infants Born Preterm. The Journal of pediatrics. 2017. This group from Monash University studied former preterm infants with polysomnography after they reached term. They included 24 babies between 27 and 36 weeks gestation at 2 to 3 weeks, 2 to 3 months and 5 to 6 months corrected age. They defined apneas as greater than 3 seconds (as long as not associated with periodic breathing). The studies lasted 2 to 3 hours on average, getting shorter as the kids got older, and therefore slept less. All of the babies had some apneas in all of the studies, about 250 total apneas on the 1st study falling to 150 on the 3rd. Average duration of the apneas was between 4 and 5 seconds, heart rates fell during the apneas by on average around 14 beats per minute, saturations fell by 2 to 4% and Brain oxygenation, measured by NIRS and expressed as the Tissue Oxygenation Index, fell by between 5 and 10% around the apneas, with the decrease being greatest at the oldest age.

I am not sure what this all means, the frequency of the apneas is actually quite similar to the frequency recorded in babies who had been full term, I don’t know if NIRS has been recorded in full term babies at these postnatal ages with apnea. It may be that the continuing pulmonary dysfunction in the ex-preterm baby makes them desaturate faster during an apnea, but I don’t know. Intermittent hypoxia  is associated with adverse outcomes in preterm infants, and this study shows it may persist for a long time. Is it associated with worse long-term outcomes? Is it affected by other treatments? Maybe we should be giving them caffeine until they stop having apneas at all, or until they go to school.

Thome UH, et al. Neurodevelopmental outcomes of extremely low birthweight infants randomised to different PCO2 targets: the PHELBI follow-up study. Archives of Disease in Childhood – Fetal and Neonatal Edition. 2017. This is a neurological and developmental follow-up of 233 babies from the 311 survivors of the randomized trial of CO2 targeting from Germany. Bayley Scores of Infant Development were not different between groups, nor were neurological findings, nor anything else. Permissive hypercapnia seems safe from this analysis, even though the original publication of the trial did not show a clear advantage.

About Keith Barrington

I am a neonatologist and clinical researcher at Sainte Justine University Health Center in Montréal
This entry was posted in Neonatal Research. Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.