Immediate Hypothermia Is Not Neuroprotective After Severe Hypoxia-Ischemia and Is Deleterious When Delayed by 12 Hours in Neonatal Rats

Abstract

Immediate and delayed (≤6 hours) HT provides neuroprotection after moderate hypoxia-ischemia in neonatal rats. This neuroprotection decreases linearly with increasing delay. After severe insults, however, immediate or delayed HT≤6 hours provides no neuroprotection. Twelve-hour delayed hypothermia increased brain injury after severe hypoxia-ischemia, which is of clinical concern.