Effects of dexmedetomidine drug in heart surgery

INTERVENTION: Intervention 1: Intervention group: High‐dose Pfizer company dexmedetomidine (0.75 ug/kg/hr) once from anesthesia induction till the end of operation. Intervention 2: Control group: Low dose Pfizer company dexmedetomidine (0.5 ug/kg/hr) once from anesthesia induction till the end of operation. CONDITION: Condition 1: Coronary artery bypass grafting. Condition 2: Aneurysms of the cardiac arteries. ; Coronary artery aneurysm and dissection ; Aortic aneurysm and dissection I25.4 PRIMARY OUTCOME: Blood and blood products transfusion. Timepoint: In operation room and 48 hours after operation. Method of measurement: Recording the amount received. Blood urea nitrogen (BUN). Timepoint: Before operation and 24, 48 and 72 hours after operation. Method of measurement: Auto‐analyzer. Cardiopulmonary bypass (CPB) duration. Timepoint: During CPB. Method of measurement: Recording the time. Creatinine. Timepoint: Before operation and 24, 48 and 72 hours after operation. Method of measurement: Auto‐analyzer. Diuretics. Timepoint: In the operation room and intensive care unit. Method of measurement: Recording the administered amounts. Inotrope medicines. Timepoint: In the operation room and until 48 hours post‐operation. Method of measurement: Recording the administered amount. Intensive care unit (ICU) stay. Timepoint: During Intensive care unit (ICU) stay. Method of measurement: Recording the time. Mean arterial blood pressure. Timepoint: Before operation and 6, 12, 24 and 48 hours after operation. Method of measurement: Vital sign monitoring system. Mechanical ventilation time. Timepoint: During operation and intensive care unit stay. Method of measurement: Recording the time. Operation time. Timepoint: During operation. Method of measurement: Recording the time. Systolic blood pressure. Timepoint: Before operation and 6, 12, 24 and 48 hours after operation. Method of measurement: Vital sign monitoring system. Urine output. Timepoint: During cardiopulmonary bypass and 24 and 48 hours after transfer to intensive care unit. Method of measurement: Urine volume measurement. INCLUSION CRITERIA: Informed consent for participation Elective open heart surgery on cardiopulmonary bypass Age over 18 years