At birth, the continuous utero-placental-umbilical infusion of glucose ends and reaches the lowest values during the first 1 to 2 hours,¹ stimulating counterregulatory mechanisms and promoting successful glucose homeostasis in healthy newborns. This occurrence is critical because the newborn brain principally uses glucose for energy and prolonged hypoglycemia has been associated with poor long-term neurodevelopment and neurocognition.^2-10 Nevertheless, little is known about whether early transient hypoglycemia, frequently considered to be a normal physiological phenomenon with no serious sequelae,^1,11 is associated with cognitive impairment.^3,4,8,12-14

Perinatal hypoxic ischemic encephalopathy (HIE) can lead to severe neurodevelopmental outcome and death. Therapeutic hypothermia is neuroprotective for infants with moderate-to-severe HIE. However, therapeutic hypothermia is only offered at high-level regional neonatal intensive care units (NICUs), necessitating the need to transport sick infants to referral centers. The goal of this study was to evaluate whether active cooling on transport is more effective than passive cooling in achieving temperatures in the treatment target range (33°C–34°C) on arrival to the Texas Children's Hospital (TCH) NICU. This was a retrospective quasi-experimental study of 42 infants who were transported to TCH for treatment of perinatal HIE between August 2012 and April 2016. Active cooling using a continuous core temperature servo-controlled cooling device (CritiCool) began in January 2014; before that, passive cooling on transport was used. Passive cooling was initiated by turning off external heating devices. Fourteen infants received active cooling, and 28 were passively cooled. Demographic data, gestational age at birth, birth weight, and Sarnat stage were not different between groups. Although TCH arrival temperatures were not different between the groups (p = 0.841), there was greater variability of temperatures in the passively cooled group (p = 0.001). More actively versus passively cooled patients arrived at the cooling center within the goal temperature range (79% vs. 25%, p = 0.003). After controlling for multiple variables, active cooling was a significant independent predictor for arriving at the cooling center within the goal temperature range. Active cooling during transport of infants with moderate-to-severe HIE was more effective than passive cooling in achieving the target goal temperature range on arrival at the cooling center. If cooling is being considered during transport, we suggest that active servo-controlled therapeutic hypothermia be used.

Background: The glucose concentrations and times to nadir for newborns of all gestational ages when intrapartum glucose-containing solutions are not routinely pro