Therapeutic hypothermia is a widely accepted methodology for mitigating injury to vital organs following ischemic insults. Cellular metabolism decreases with lower temperatures and this reduction in metabolism protects metabolically active organs including the heart and brain during episodes of ischemia and hypoxia. Therapeutic hypothermia is currently practiced in association with a number of surgeries and transplants and for the treatment of strokes and heart attacks. Existing cooling methodologies include surface cooling, extracorporeal cooling, and intravascular cooling which are too time-consuming, highly invasive, or ineffective. Mayo Clinic researchers have exploited the large surface area of the lungs and the immediate proximity of the vasculature to devise a novel means of transpulmonary heat exchange for the purposes of inducing therapeutic hypothermia. Ventilation of patients with cooled gases or atomized liquid/gas mixtures represents a novel non-invasive means of achieving relatively rapid hypothermia via transpulmonary heat exchange.
Application An efficient non-invasive method of inducing therapeutic hypothermia could have several applications in surgery and management of patients who have undergone trauma. This technology could be used in the field, in ambulances, emergency rooms and intensive care units to limit or prevent ischemia-related damage.
Stage of Development Efficacy of transpulmonary induction of hypothermia has been demonstrated in rat and pig studies. Lower esophageal temperature, a surrogate for intra-pulmonary artery core temperature, was lowered by 0.17 degrees Celsius per minute during the first 30 minutes in pig feasibility studies.