Background and purpose: Hypothermia is neuroprotectant but currently available cooling methods are laborious, invasive, and require whole-body cooling. There is a need for less invasive cooling of the brain. This study was conducted to assess the safety and efficacy of temperature reduction of the RhinoChill transnasal cooling device.
Methods: We conducted a prospective single-arm safety and feasibility study of intubated patients for whom temperature reduction was indicated. After rhinoscopy, the device was activated for 1 hour. Brain, tympanic, and core temperatures along with vital signs and laboratory studies were recorded. All general and device-related adverse events were collected for the entire hypothermia treatment.
Results: A total of 15 patients (mean age, 50.3 ± 17.1 years) were enrolled. Brain injury was caused by intracerebral hemorrhage, trauma, and ischemic stroke in equal numbers. Hypothermia was induced for fever control in 9 patients and for neuroprotection/intracranial pressure control in 6. Core temperature, brain temperature, and tympanic temperature were reduced an average of 1.1 ± 0.6°C (range, 0.3 to 2.1°C), 1.4 ± 0.4°C (range, 0.8 to 5.1°C), and 2.2 ± 2°C (range, 0.5 to 6.5°C), respectively. Only 2 patients did not achieve the goal of ≥1°C decrease in temperature. Brain temperature, tympanic temperature, and core temperature reductions were similar between the afebrile and febrile patients. There were no unanticipated adverse events and only 1 anticipated adverse event: hypertension in 1 subject that led to discontinuation of cooling after 30 minutes. There were no nasal complications.
Conclusions: Intranasal cooling with the RhinoChill device appears safe and effectively lowers brain and core temperatures. Further study is warranted to assess the efficacy of hypothermia through intranasal cooling for brain-injured patients.