Parameters of Cerebral Perfusion

Blood Pressure or Cardiac Output - the Influence on Cerebral Perfusion During Cardiopulmonary Bypass

The purpose of this study is to determine whether cerebral blood flow and cerebral tissue oxygenation is most dependent on cardiac output or on mean arterial pressure in patients undergoing cardiac surgery with the use of cardiopulmonary bypass.

Inclusion Criteria:

• Undergoing cardiopulmonary bypass for CABG a
• having an appropriate temporal bone window for reliable TCD monitoring
• needing pharmacological intervention because of hypotension before going on CPB.

Exclusion Criteria:

• requiring hypothermia during surgery
• requiring emergency surgery
• contraindication for phenylephrine,
• having known brain pathology (e.g. Cerebral Vascular Accident (CVA) or increased intracranial pressure
• having a history of severe carotid artery stenosis.