A novel selective cooling system for the brain: feasibility study in rabbits vs piglets

Area of Science:

• Physiology
• Medical Devices
• Hypothermia Research

Background:

• Selective brain cooling (SBC) offers an alternative to systemic hypothermia for managing neurological complications.
• Nasopharyngeal SBC using a vortex tube has been developed as a simple and effective method.
• This study evaluates SBC in rabbits and compares findings to piglets, which possess a carotid rete.

Purpose of the Study:

• To assess the efficacy of nasopharyngeal selective brain cooling in rabbits.
• To compare the effectiveness of SBC in rabbits (lacking a carotid rete) versus piglets (with a carotid rete).
• To validate the nasopharyngeal vortex tube method for targeted brain temperature reduction.

Main Methods:

• Six rabbits underwent two cooling experiments each.
• Brain temperature was monitored via an implanted thermometer; body temperature via an esophageal probe.
• Cooling involved nasopharyngeal insufflation of room-temperature or cold air (-7°C) at 14-15 L/min for 60 minutes.

Main Results:

• Room temperature air cooling resulted in a brain temperature of 34.2°C (cooling rate: 3.7°C/h).
• Cold air cooling achieved faster mean brain cooling rates of 5.2°C/h.
• Esophageal body temperature remained above 36°C throughout the cooling and maintenance periods.

Conclusions:

• The nasopharyngeal vortex tube facilitates rapid selective brain cooling in rabbits.
• The study confirms that the absence of a carotid rete does not impede nasopharyngeal SBC.
• This demonstrates the potential of the nasopharyngeal method for targeted brain cooling across different mammalian physiologies.