Due to the difficulty of recruiting patients and the fact that, despite the team's best efforts, the inclusion period initially planned had largely passed, it did not appear ethical to continue the study.

Hypoxic-ischaemic brain injury (HIBI) is the main cause of death in patients who are comatose after resuscitation from cardiac arrest. Current guidelines recommend to target a mean arterial pressure (MAP) above 65 mmHg to achieve an adequate organ perfusion. Moreover, after cardiac arrest, cerebral autoregulation is dysregulated and cerebral blood flow (CBF) depends on the MAP. A higher blood pressure target could improve cerebral perfusion and HIBI. Transcranial Doppler (TCD) is a non-invasive method to study CBF and its variations induced by MAP.

The aim of this study is to test the feasibility of an early-goal directed hemodynamic management with TCD during the first 12 hours after return of spontaneous circulation (ROSC).

Inclusion Criteria:

• Patients admitted in the Intensive Care Unit (ICU) under mechanical ventilation with a Glasgow Coma Scale ≤ 8/15 after in- or out-of-hospital cardiac arrest
• Mean arterial pressure between 65 and 85 mmHg with or without vasopressor support

Exclusion Criteria:

• Age < 18 years old
• No flow (time between cardiac arrest and the beginning of cardiac massage) > 15 minutes or unknown
• Low flow ((time between cardiac arrest and ROSC: return of spontaneous circulation)> 60 minutes
• Time between ROSC and inclusion > 12 hours
• Transcranial doppler unavailable
• Cardiac arrythmia
• Patient under extracorporeal life support before inclusion or at risk of being referred for assistance due to cardiogenic shock with high dose of vasopressors before inclusion (MAP < 65 mmHg with norepinephrine or epinephrine > 1 µg/kg/min or dobutamine > 10 µg/kg/min)
• Severe cardiac dysfunction defined by left ventricular ejection fraction < 20% or aortic Velocity Time Integral (VTI: measured with trans-thoracic echocardiography) < 14 cm with dobutamine > 10µg/kg/min
• Patient under Extracorporeal Membrane Oxygenation (ECMO) for Acute Respiratory Distress Syndrome (ARDS) before inclusion
• Cardiac arrest secondary to brain injury such as stroke, subarachnoid hemorrhage or traumatic brain injury
• Hemorrhagic shock
• Any acute pathology that requires strict blood pressure control (aortic dissection, stroke, cardiogenic pulmonary edema with high blood pressure)
• Decision of withdrawing or withholding life sustaining treatment before inclusion or considered during the first 12 hours of ICU management
• Patient with a modified Rankin scale (MRS) 4 or 5 prior to resuscitation
• Pregnancy or lactation
• Patients already enrolled in another clinical study on cardiac arrest
• Patients with judicial protection
• No social security coverage