Post-cardiac arrest ischemia/reperfusion phenomenon led to organs injury and failure. Among the different organs, gastro-intestinal tract injury could contribute to post-cardiac arrest shock.

The ischemic injury of the gastro-intestinal (GI) tractus is suggested by abnormalities in digestive biomarkers and by the frequent endotoxemia after CA. However, direct mucosal damage has not been clearly demonstrated after OHCA. The real incidence of ischemic lesions of GI tract and their potential involvement in the post-CA shock is therefore unknown.

We propose an original clinical research program aimed at rigorously determining the incidence of upper GI lesions after OHCA and analyzing their contribution to the severity of post-CA shock through a prospective, interventional, multicentric study

The screening of the patients will be performed 2 to 4 days after their Intensive Care Unit (ICU) admission. Procedure and exams at the day of inclusion (day 0):

• collection of digestive symptoms
• carrying out the œsophago-gastro-duodenoscopy and establishment of a formal report with the eventual lesions and their ischemic nature.
• in the absence of contra-indication and upon final decision of the gastroscopist, systematic biopsies of fundic, antral and duodenal mucosa; contra-indication of biopsies are the presence of a vascular or haemorrhagic lesion and the coagulation disorders.
• Blood sample for H. pylori serology, and serum freezing. Urinary sample for urine freezing

Procedure and exams from day 1 to hospital discharge:

• Daily collection of digestive symptoms and needs for vasopressor support
• Sepsis-related Organ Failure Assessment (SOFA) score at day 2 & 5
• Cerebral Performance Category (CPC) score determination at hospital discharge In case of digestive symptoms after day 0 and in accordance with good clinical practice, a second gastroscopy and/or an abdominal Computed Tomography scan(CT-scan) and/or a colonoscopy will be performed at the physician's discretion.

Inclusion Criteria:

• Adult patient hospitalized for less than 5 days in a participating Intensive Unit Care following successfully resuscitated out-of-hospital cardiac arrest
• Patient still mechanically ventilated
• Hypothermia period over, corporal temperature > 36°C.
• Written consent from a next of kin

Exclusion Criteria:

• In-hospital cardiac arrest
• Patients extubated before gastroscopy
• Contra-indication of gastroscopy: suspicion of digestive perforation, severe bleeding diathesis despite coagulation products transfusion, or suspicion of Creutzfeldt-jacob disease
• Patients with cardiac valvular prosthesis or previous endocarditis
• Pregnancy, lactating women In case of severe coagulation disorders (platelet count < 30 G/L, International Normalized Ratio (INR) > 2) or heparin treatment or combined platelet inhibition treatment, the inclusion of the patient will be possible but digestive biopsies will not be allowed.