Published online Feb 8, 2016. doi: 10.5409/wjcp.v5.i1.67
Peer-review started: August 3, 2015
First decision: October 13, 2015
Revised: November 18, 2015
Accepted: December 17, 2015
Article in press: December 18, 2015
Published online: February 8, 2016
Processing time: 180 Days and 22 Hours
Interruption of blood flow and gas exchange to the fetus in the perinatal period, known as perinatal asphyxia, can, if significant, trigger a cascade of neuronal injury, leading on to neonatal encephalopathy (NE) and resultant long-term damage. While the majority of infants who are exposed to perinatal hypoxia-ischaemia will recover quickly and go on to have a completely normal survival, a proportion will suffer from an evolving clinical encephalopathy termed hypoxic-ischaemic encephalopathy (HIE) or NE if the diagnosis is unclear. Resultant complications of HIE/NE are wide-ranging and may affect the motor, sensory, cognitive and behavioural outcome of the child. The advent of therapeutic hypothermia as a neuroprotective treatment for those with moderate and severe encephalopathy has improved prognosis. Outcome prediction in these infants has changed, but is more important than ever, as hypothermia is a time sensitive intervention, with a very narrow therapeutic window. To identify those who will benefit from current and emerging neuroprotective therapies we must be able to establish the severity of their injury soon after birth. Currently available indicators such as blood biochemistry, clinical examination and electrophysiology are limited. Emerging biological and physiological markers have the potential to improve our ability to select those infants who will benefit most from intervention. Biomarkers identified from work in proteomics, metabolomics and transcriptomics as well as physiological markers such as heart rate variability, EEG analysis and radiological imaging when combined with neuroprotective measures have the potential to improve outcome in HIE/NE. The aim of this review is to give an overview of the literature in regards to short and long-term outcome following perinatal asphyxia, and to discuss the prediction of this outcome in the early hours after birth when intervention is most crucial; looking at both currently available tools and introducing novel markers.
Core tip: Perinatal asphyxia is a significant cause of acquired brain injury occurring in the neonatal period. A reliable early marker for predicting injury severity and sequelae remains elusive. The advent of therapeutic hypothermia as an effective neuroprotective intervention has changed the prognosis for affected infants. In this review we summarise what is known about the short and long term outcome for infants with perinatal asphyxia in the pre- and post-cooling era. We also describe currently available early indicators of outcome and introduce the exciting field of emerging novel biomarkers, both chemical and physiological.