Regardless of the development of cardiac surgery techniques and technologies, the question of an optimal extracorporeal circulation is still unanswered. There are globally accepted standards of perfusion, however, keep many of these procedures was not evidence-based review.

Generally accepted are flow rates during cardiopulmonary bypasses of 2.5 L/min/m2. This target was derived from the physiological conditions, but they are not the result of an adapted adjustment to the fundamentally non-physiological processes during extracorporeal circulation. Among other things, an increased metabolic demand during re-perfusion is not taken into account.

An increasing and optimizing of the standard flow rate of 0.5 L/min/m2 should be the aim of this investigation. Under optimal perfusion, the investigators are maintaining the microcirculation and organ protection in receipt of endothelial function and oxygen transport.

Inclusion Criteria:

• Extracorporeal circulation
• Age > 18
• Written consent

Exclusion Criteria:

• Emergency cases