Selective Cooling of the Brain in Newborn Piglets and Rabbits Using a Novel Nasopharyngeal Method

Introduction Mild hypothermia has become an effective neuroprotective strategy following head trauma, cardiac arrest and neonatal asphyxia. However, cooling the whole body below 33-34°C can induce severe complications; therefore, selective brain cooling (SBC) could minimize adverse effects by maintaining core body temperature at normal values over an extended period of time. Recently, we developed a novel method of SBC and demonstrated its safety and efficacy in a piglet model. The method was based on spraying room temperature or cold air into the nostrils at different flow rates. Pigs possess a carotid rete (a set of small parallel arteries) which is surrounded by the cavernous sinus; together these serve as an effective heat exchanger for the brain. However, in mammals in which the carotid rete is missing such as rabbits and humans, some suggest that there is no effective heat exchange in the cavernous sinus and, consequently, SBC is not efficient in these species.