Comparison of drugs for anxiety relief before heart surgery

INTERVENTION: Adjuvants, Anesthesia Drug The patients wil be divided into 3 groups(n=30 in each). The groups will receive the medication 45 minutes prior to surgery. Midazolam group:midazolam 7,5 mg, orally. Morphine group: morphine 0,2 mg/kg, to maximum dose of 14 mg. Clonidine group: clonidine 5 mg/kg, to maximum dose of 300mg. Interventions on arrival to operating room: Blood pressure, heart and respiratory rate and arterial oxygen saturation by pulse oximeter, will be measured. CONDITION: Patients with cardiac disease who will undergo cardiac surgery ; Thoracic Surgery Thoracic Surgery PRIMARY OUTCOME: The effect of midazolam, clonidine and morphine on the systolic arterial pressure in patients undergoing cardiac surgery, on arrival to operating room. On arrival to operating room will be measured the blood pressure (systolic) of patient. SECONDARY OUTCOME: Effects of three drugs on cardiac rate. Will be measured the cardiac rate on arrival to operating room. Effects of three drugs on level of anxiety. Anxiety will be measured by visual analog scale (VAS), on arrival to operating room. Effects of three drugs on level of sedation. Sedation will be evaluated by Ramsay Scale. Effects of three drugs on oxygen saturation level. The arterial oxygen saturation level will be measured by pulse oximeter. Effects of three drugs on perception of pain caused by arterial and venous puncture. The pain perception will be evaluated by VAS. Effects of three drugs on recall (amnésia). The amnésia will be evaluated by showing to patients 3 pictures and 3 words, printed on a card. At postoperative period, after awakening, the patients will be queried to recall of the pictures and words. Effects of three drugs on respiratory rate. The respiratory rate will be measured on arrival to operating room. INCLUSION CRITERIA: Patients undergoing cardiac surgery with cardiopulmonary bypass; age of 18‐65 years.