Prognosticating the Outcomes of HIE with Certainty: Mission Impossible? - Commentary on "Clinical Prediction Models and Predictors for Death or Adverse Neurodevelopmental Outcome in Term Newborns with Hypoxic Ischemic Encephalopathy: A Systematic Review of the Literature".

Abstract

Inevitably, one of the first questions asked by parents of neonates admitted to the neonatal intensive care unit with hypoxic ischemic encephalopathy (HIE) is “will my baby be okay?” This is, of course, a multifaceted question that likely relates to both survival and long-term neurodevelopmental outcomes. However, there are significant challenges in prognosticating the outcomes of HIE with certainty. Therapeutic hypothermia (TH) is the standard of care for near-term and term neonates with moderate or severe HIE in high-income countries as evidenced by both safety and efficacy of the treatment in systematic reviews and meta-analyses of large multicenter trials involving over 1,500 neonates [1]. Although TH has improved mortality and neurodevelopmental impairment, the adverse outcomes remain significant. Indeed, HIE is the single greatest contribution to disability worldwide and accounts for one-tenth of all disability-adjusted life years [2]. In 1973, Brown et al. [3] first described that when asphyxia occurred in association with subsequent neurological signs there might be long-term adverse outcomes. Since then, various clinical, biochemical, neurophysiological, neuroimaging, and neurobehavioral findings have been studied regarding the respective prognostic values on HIE outcomes individually and in combination in prediction models. However, most prognostic factors that have been identified are available late after the hospital admission, during or after TH. Excluding those publications prior to the era of TH and due to other ineligible factors, over 100 studies have been published to examine the prediction of HIE outcomes. Dr. Langeslag et al. [4] took on the daunting task of performing a systematic review of prediction models. Their review is comprehensive, rigorous and it follows the PRISMA and CHARMS guidelines with a robust and transparent search strategy and risk of bias assessment. The work provides a detailed review of the literature of prediction models and predictors for death and adverse neurodevelopmental outcomes in neonates with HIE during the therapeutic hypothermia era. While it is evident that the initial aim was to identify clinical prediction models for death or adverse neurodevelopmental outcome, given the methodological