taVNS Treatment for NeuroICU Patients

Inclusion Criteria: * Age ≥18 * Admission to the NeuroICU within 36 hours of onset of an acute medical condition. * Patient or authorized legal representative should be able to provide consent within 36 hours of ICU arrival * Presence of at least one predictor of critical illness and/or severe brain / spinal cord injury: * Glasgow Coma Scale GCS \>3 \& \<= 12 at admission * NIH stroke scale of 6 or greater * Requirement for ongoing mechanical ventilation * Requirement for ongoing vasopressor support * Diagnosis of subarachnoid hemorrhage * Diagnosis of intracerebral hemorrhage with hematoma volume \> 5 ml * Diagnosis of moderate-severe traumatic brain injury (GCS \>3 \& \<= 12) * Refractory Status epilepticus requiring continuous sedative infusions Exclusion Criteria: * Systemic immunosuppression * Receiving ongoing cancer therapy * Implanted electrical device (e.g., pacemaker, stimulator) * Bradycardia on admission (Sustained bradycardia on arrival with a heart rate \< 50 bpm for \>5 minutes) * Risk of imminent death or limitation of care (e.g., Glasgow Coma Scale of 3, pupillary dilatation) * Expected ICU stay of less than 72 hours, as determined by attending physician or ICU fellow * Pregnancy * COVID-19