Safety evaluation of nasopharyngeal cooling (RhinoChill®) in stroke patients: an observational study.

Introduction: New technologies for therapeutic cooling have become available. The objective of our study was to investigate the safety of nasopharyngeal cooling with the RhinoChill(®) device in stroke patients, focusing on systemic and neurovital parameters.

Methods: In this prospective observational study, consecutive patients with severe ischemic or hemorrhagic stroke who underwent intracranial pressure (ICP) and brain temperature monitoring have been enrolled. Ten patients who were treated with the RhinoChill(®) device were analyzed. Brain and bladder temperature and systemic and neurovital parameters were monitored continuously. Additional evaluations of safety included bleeding complications and otolaryngological examinations.

Results: Baseline brain temperature of 36.7 °C (SD 0.9) decreased by an average of 1.21 °C (SD 0.46) within 1 h, the effect of brain temperature decrease ranged from a maximum of 2 °C (patients 3 and 7) to a minimum of 0.6 °C (patient 4). Within the first several minutes after initiating RhinoChill(®) treatment, 3 of 10 patients experienced an increase in systolic arterial pressure by 30, 30, and 53 mmHg, respectively. Heart rate rose as well (mean 3 bpm, SD 2.9). ICP and oxygen saturation were unaffected by the treatment. We observed 1 bleeding complication in the control CT scan of patient 10. Rhinoscopical findings 3 days after nasopharyngeal cooling and at the follow-up (>6 months) and a 16-item smell test were normal.

Conclusion: The RhinoChill(®) system cools the brain efficiently. However, steep increases in blood pressure raise serious concerns regarding the safety of its use in stroke patients.