Is It Feasible and Safe to Wake Cardiac Arrest Patients Receiving Mild Therapeutic Hypothermia After 12 Hours to Enable Early Neuro-Prognostication? The Therapeutic Hypothermia and Early Waking Trial Protocol

Abstract

Mild therapeutic hypothermia (MTH 33°C) post out-of-hospital cardiac arrest (OHCA) is widely accepted as standard of care. However, uncertainty remains around the dose and therapy duration. OHCA patients are usually kept sedated±paralyzed and ventilated for the first 24-36 hours, which allows for targeted temperature management, but makes neurological prognostication challenging. The aim of this study is to investigate the feasibility and safety of assessing the unconscious OHCA patient after 12 hours for early waking/extubation while continuing to provide MTH for 24 hours, and fever prevention for 72 hours by using an intravenous temperature management (IVTM) system and established conscious MTH anti-shiver regimens. This is a single-center, prospective, non-randomized observational study that will compare the results of early awakening (at 12 hours) with historical controls. A total of 50 consecutive unconscious survivors of OHCA, treated with MTH, who meet the Therapeutic Hypothermia and eArly Waking (THAW) inclusion criteria will be enrolled. The patient will receive MTH by using IVTM. After 12 hours of MTH, patients will be assessed by using strict clinical criteria to determine suitability for early waking and extubation. Once awake and extubated, MTH will continue for 24 hours with skin counter-warming and anti-shiver regimen followed fever prevention up to 72 hours. All patients will have serial electroencephalogram (EEG), somatic sensory potential, and neuro-biomarkers performed on admission to intensive care unit, 6 and 12 hours, then every 24 hours until 72 hours. The study has been approved by the National Research Ethics Service, Health Research Authority.

Keywords: early positive neurological prognostication; temperature management and early waking; therapeutic hypothermia.