Effect of Naloxegol on Postoperative Ileus in Patients Undergoing Cardiac Surgery

Inclusion Criteria: * \> 18 years old, * Undergoing cardiac surgery with cardiopulmonary bypass, * For women of child bearing potential without contraception, beta-HCG negative result * Having signed a written informed consent form, * Affiliation to the social security system. Exclusion Criteria: * Allergy or known hypersensitivity to Naloxegol or any of the excipients or any other opioid antagonist * Pregnant or breastfeeding women * Severe hepatic failure, history of cirrhosis * Moderate or severe renal failure (GFR\<60ml/min) * Concomitant treatment with a strong cytochrome P450 3A4 inhibitor * History of acute gastro-intestinal obstruction known or suspected * History of digestive arteritis * Clinically relevant alteration of the blood-brain-barrier * Cancer with increased risk of gastro-duodenal perforation * Disorder that could alter the integrity of the gastrointestinal lining * Regular treatment with laxative drugs * Concomitant treatment with methadone * Patient unable to take a drug by oral route * Patient under protection of the adults (guardianship, curators or safeguard of justice), * Patient included or planning to be included in another research protocol relating to medications.