First Clinical Experience with Intranasal Cooling for Hyperthermia in Brain-Injured Patients

Introduction Hyperthermia is common in brain-injured patients and associated with a worse outcome. As brain rather than body temperature reduction, theoretically, is the most important in cerebral protection, there is logic in targeting cooling at the brain. Selective brain cooling can, in theory, be obtained by cooling the skull or by heat loss from the upper airways. In this preliminary safety and efficacy study, we report clinical data from brain-injured patients who because of hyperthermia were treated with intranasal cooling. Methods Nine intubated brain-injured patients with hyperthermia were treated using a prototype intranasal balloon system perfused with cold saline. Temperature in the cerebrum, esophagus, and bladder was monitored together with intracranial pressure. Results In only two of nine patients, normothermia was reached in the esophagus and in only four of nine patients it was reached in the bladder. When normothermia was reached, the time to normothermia was delayed. In the brain, normothermia was reached in two of five patients after approximately 72 h. Median temperature curves from the first 72 h of cooling showed that normothermia was not reached in any of the three compartments. The temperature in the brain and bladder were on average 0.6 and 0.5 °C higher than in the esophagus. ICP increased with increasing brain temperature. We found no signs of clinical important injury to the nasal mucosa from the cold saline or pressure in the balloons. Conclusion In brain-injured patients with hyperthermia, cooling with a prototype intranasal balloon system was clinically inadequate as the effect was delayed and not brain selective.