Early Cessation of Sedation and TTM in Patients With a Favourable EEG After Cardiac Arrest

Comatose patients after cardiac arrest are treated on intensive care units with sedative medication, targeted temperature management (TTM), mechanical ventilation, and hemodynamic support. Despite substantial variation in the severity of the encephalopathy and even lack of unequivocal evidence of efficacy of sedation and TTM, all patients receive standard treatment. The severity of the postanoxic encephalopathy can reliably be assessed with the electroencephalogram (EEG). A continuous EEG pattern within the first 12 hours after cardiac arrest ("favorable EEG") is strongly associated with a good neurological outcome and reflects a very mild or transient encephalopathy. The investigators hypothesize that this subgroup of patients, with a favorable EEG will not benefit from prolonged sedation and TTM.

The objective of this study is to estimate the feasibility and safety of early weaning from ICU treatment in patients after cardiac arrest and an early (< 12 h) favourable EEG pattern. The study design is a cluster randomized crossover design with two treatment arms. The intervention contrast will be early cessation of sedation and TTM, with subsequent weaning from mechanical ventilation if appropriate (intervention group) vs. standard care, including sedation and TTM for at least 24-48 hours (control group). The investigators will include forty adult patients admitted to the ICU with postanoxic encephalopathy after cardiac arrest and an early (<12 hours) favorable EEG pattern.

Inclusion criteria

• Patients after cardiac arrest admitted to the ICU for treatment with sedation, TTM and mechanical ventilation.
• Age 18 years or older.
• Continuous EEG measurement started within 12 hours after cardiac arrest.
• Favourable EEG pattern within 12 hours after arrest, defined as a continuous background pattern (NVN, 2019; Ruijter et al., 2019).
• Possibility to stop sedative treatment within three hours after identification of a favourable EEG pattern.
• Written informed consent (deferred).

Exclusion criteria

• A known history of another medical condition with limited life expectancy (<6 months).
• Any progressive brain illness, such as a brain tumour or neurodegenerative disease.
• Pre-admission Glasgow Outcome Scale Extended score of 4 or lower.
• Reason other than neurological condition to continue sedation and/or ventilation.
• Follow-up impossible due to logistic reasons.