Patients scheduled for elective cardiac surgery are preoperative evaluated using different personality type, stress and anxiety tests.

Patient are randomized to receive the investigators' standard moderate dose sufentanil (bolus 1microgram/kg and propofol 0.03 mg/kg/min) or low dose sufentanil (bolus 0.5 microgram/kg and propofol 0.06 mg/kg/min).

Patients randomized and the type of induction informed to the anaesthetist 30 minutes before surgery.

Patients are monitored before induction of anesthesia. Propofol is started on the randomized infusion rate. Sufentanil bolus are given according to randomization. BIS level is followed. Time to reach BIS < 50 is monitored. BIS after 30, 60 and 90 minutes are registered. Lowest BIS during surgery are registered. Total amounts of sufentanil and propofol recorded.

Inclusion Criteria:

• All elective cardiac surgery patients

Exclusion Criteria:

• Patients requiring special attention or monitoring during induction
• Patients with expected longer postoperative ventilation time
• Patients allergic to sufentanil and or propofol
• Participation in other projects
• Pregnancy