Many risk factors have been identified for delirium after open heart surgery . One of the main risk factors; duration of stay on mechanical ventilator . Our hypothesis; The use of sevoflurane during aortic cross-clamping reduces the need for long-acting intravenous anesthetic agents. Therefore, patients will be weaned from the mechanical ventilator in a shorter time. Patients with shorter stays on mechanical ventilation develop less postoperative delirium.

Standard anesthesia management will be applied in the induction and maintenance of anesthesia. In the induction of anesthesia 1mg/kg lidocaine , 1.5-2mg/kg propofol , 1 mcg /kg fentanyl citrate, 0.6 mg/kg rocuronium bromide will be administered. Sevoflurane for maintenance of anesthesia and propofol and fentanyl if needed bolus will be applied. BIS monitoring will be performed to control the depth of anesthesia. Patients' peroperative hemodynamic levels, arterial blood gas levels, operation time, pump time, aortic cross clamp time, postoperative complications , the amount of blood and fluid used, the amount of iv anesthetic used, the extubation time, the length of stay in the intensive care unit, the length of stay in the hospital will be followed and recorded. Postoperative delirium follow-ups of the patients will be recorded once a day by the same investigator using the Nursing Delirium Screening Scale and Delirium Rating Scale Revised-98 until they are discharged from the hospital .

Inclusion Criteria:

Patients with a score of 25 and above in the mini-mental state test performed in the preoperative period

Exclusion Criteria:

Those who are scheduled for emergency surgery

Those with known dementia and/or neurological disease

Patients who will have elective open heart surgery, patients over the age of 18, and patients with a score of 25 and above in the mini mental state test performed in the preoperative period will be included in the study.