Objective: To assess neurologic prognostication by early Transcranial Doppler Sonography (TCD) in comatose survivors after cardiac arrest.

Design: Prospective study between May 2016 and November 2017 in a medical intensive care unit and cardiac intensive care unit in a university hospital.

Patients: all comatose patients older than 18 years successfully resuscitated from an out-of-hospital cardiac arrest (OHCA). Patients for whom OHCA is associated with traumatic brain injury, no window for TCD measurements, or dead before neurological prognostication are excluded.

The investigators measure the pulsatility index (PI) and diastolic flow velocity (DFV) of the right and left middle cerebral artery during the first 12 h after return of spontaneous circulation (ROSC). The highest value of DFV and the lowest of PI will use for the statistical analysis. Cerebral Performance Category evaluate neurologic outcome at hospital discharge.

Data provided by early TCD after ROSC are associated with neurological outcome. The use of these data could lead to the development of therapeutics improving cerebral perfusion in patient resuscitated from an OHCA.

Inclusion Criteria:

• older 18 years
• out-of-hospital cardiac arrest with recovery of spontaneous cardiac activity

Exclusion Criteria:

• transcranial doppler not done or not interpretable
• associated cranial trauma
• died without neurological assessment

Patients resuscitated from out-of-hospital cardiac arrest