Head cooling with mild systemic hypothermia in anesthetized piglets is neuroprotective

Hypothermia is potentially therapeutic in the management of neonatal hypoxic-ischemic brain injury. However, not all studies have shown a neuroprotective effect. It is suggested that the stress of unsedated hypothermia may interfere with neuroprotection. We propose that selective head cooling (SHC) combined with mild total-body hypothermia during anesthesia enhances local neuroprotection while minimizing the occurrence of systemic side effects and stress associated with unsedated whole-body cooling. Our objective was to determine whether SHC combined with mild total-body hypothermia while anesthetized for a period of 24 hours reduces cerebral damage in our piglet survival model of global hypoxia-ischemia. Eighteen anesthetized piglets received a 45-minute global hypoxic-ischemic insult. The pigs were randomized either to remain normothermic or to receive SHC. We found that the severity of the hypoxic-ischemic insult was similar in the SHC versus the normothermic group, and that the mean neurology scores at 30 and 48 hours and neuropathology scores were significantly better in the SHC group versus the normothermic group. We conclude that selective head cooling combined with mild systemic hypothermia and anesthesia is neuroprotective when started immediately after the insult in our piglet model of hypoxic-ischemic encephalopathy. Ann Neurol 2003;53:000–000