Therapeutic Hypothermia and eArly Waking

This study is a single centre, prospective, feasibility and safety study. Consecutively enrolling 50 patients. Subjects will include adult patients who have suffered a cardiac arrest with a return of spontaneous circulation (ROSC). To qualify, patients must be unconscious and intubated because their initial Glasgow Coma Score (GCS) is \<8. Intravenous therapeutic hypothermia (TH) will be established in the cathlab and maintained for 24 hours whilst being cared for in the intensive Care Unit (ICU). IVTM will maintain the patient's core temperature at a target temperature between 32-34 degrees Celsius. After the patient has received 12 hours of TH, sedation will be stopped and the patient will have a comprehensive neurological assessment combining electroencephalogram (EEG), Somatic Sensory Evoked Potential (SSEP) and neurological biomarkers, Neuron Specific Enolase (NSE) and S100b. The EEG, SSEP and biomarkers will be reviewed by an expert in neurophysiology at a core lab off-site. These results will be reviewed retrospectively, therefore will not influence the medical management of the patient. Patients who are clinically stable and not showing any adverse neurological signs will be extubated after 12 hours. Patients who don't meet the early waking criteria will reassessed every 6 hours for extubation. Those patients who are not suitable to be woken early or remain unconscious after 24 hours will be reassessed as per standard practice for unconscious survivors of cardiac arrest.