Initiation of passive cooling at referring centre is most predictive of achieving early therapeutic hypothermia in asphyxiated newborns.

Objective: To identify factors associated with early initiation and achievement of therapeutic hypothermia (TH) in newborns with hypoxic-ischemic encephalopathy (HIE).

Methods: Retrospective cohort study of newborns who received TH according to National Institute of Child Health and Human Development (NICHD) criteria in two academic level 3 Neonatal Intensive Care Units (NICU) between 2009 and 2013. All infants were transported by a neonatal transport team (NNTT). Multivariate linear regression including who initiated cooling and degree of resuscitation in the model was performed.

Results: Two hundred and seven infants were included. Waiting for advice from a tertiary care NICU was independently associated with a 50 minute delay in the median time of initiation of TH. The need for extensive resuscitation (cardiopulmonary resuscitation [CPR] or epinephrine) was independently associated with a reduction of 43 minutes in the median time to reach target core temperature. Log-transformed time to initiation of TH was associated with time to reach target core temperature (P<0.001). A doubling of time to initiation of TH corresponds to a 24% (95% CI 18% to 30%) increase in median time to reach target core temperature.

Conclusions: Initiating passive cooling at the referring centre, before transfer, is critical to faster achievement of target core temperature in asphyxiated infants. Greater outreach education and development of clinical care pathways are needed to improve optimal delivery of TH to enhance outcome.