The purpose of this study is to analyze the Ketamine with its anti-inflammatory profile would be able to prevent cognitive disorders in the postoperative period of cardiac surgery, since these disorders contribute to an impact on morbidity / mortality in this population.

Inclusion Criteria:

• Patients aged over 50 years.
• Be submitted to cardiac surgery by sternotomy and with the use of cardiopulmonary bypass (CPB).
• American Society of Anesthesiologists classification 1, 2,3 and 4.

Exclusion Criteria:

• Patients undergoing reoperation.
• Patients undergoing heart transplantation.
• Patients using vasopressor agents and / or ionotropic continuous preoperatively.
• Patients with prior endotracheal intubation and consequently Ventilatory Assistance Mechanics.
• Patients with documented psychiatric disorders.
• Patients with previous cognitive disorders.
• Patients with a history of alcohol or drug abuse.
• Patients with a history of cerebrovascular accident (CVA) with less than 3 months.