The Danish Out-of-Hospital Cardiac Arrest Study

After resuscitation from Out-of-Hospital Cardiac Arrest (OHCA) patients experience Post Cardiac Arrest Syndrome due to ischemia and reperfusion injury. It consists of systemic inflammation, cerebral and myocardial dysfunction, and the condition that led to the arrest. Most OHCA patients will receive critical care intubated in an Intensive Care Unit (ICU). Despite this \~50% die; mainly due to brain injury. Several targets can be considered for improving outcomes. To dampen systemic inflammation and optimize cerebral perfusion seem important. Deep sedation has been required for targeted temperature management (TTM) but may also be brain protective. After end of sedation, many patients have some cerebral dysfunction that may facilitate delirium. The aim of this trial is therefore to improve treatment of comatose OHCA patients by evaluating 4 interventions in a factorial design addressing each of these targets in a randomized clinical trial: 1. Systemic inflammation: Anti-inflammatory treatment with high dose steroids (dexamethasone) or placebo. 2. Cerebral perfusion: Backrest elevation during sedation at 5 or 35 degrees. 3. Duration of sedation: Early wakeup call and potential extubation at ≤6 hours after admission or later as current standard practice at 28-36 hours. 4. Delirium: Prophylactic treatment with anti-psychotic medication (olanzapine) or placebo. The trial is designed as a phase III trial, randomizing 1000 patients at Danish cardiac arrest centers. The primary endpoint is 90 days all-cause mortality for the interventions targeting systemic inflammation and cerebral perfusion, while it is days alive outside of hospital within 30 days for the interventions concerning duration of sedation and delirium. The trial has potential to improve outcomes for comatose OHCA patients - a group with a grave prognosis with currently only limited evidence-based treatments.

Inclusion Criteria: 1. Age ≥18 years 2. OHCA of presumed cardiac cause 3. Sustained ROSC, defined as persistent signs of circulation and no need for chest compressions or mechanical circulatory support for 20 minutes 4. Unconsciousness (GCS \3 hours (180 minutes) from ROSC to screening 10. Systolic blood pressure \