The goal of the study is the evaluation of the air handling of a "new" type of oxygenator versus the standard model. The new type has an integrated arterial filter. The standard model has a non integrated arterial line filter. If the air handling is as effective/ better than in the standard model this can lead to reduction of cardiopulmonary bypass circuits with their initiation of systemic inflammatory response and improve cardiopulmonary bypass safety.

Inclusion Criteria:

• All children with body surface area between 0.25 and 0.5 m² who need cardiac surgery with cardiopulmonary bypass.

Exclusion Criteria:

• Urgent and norwood procedures.

All children with body surface area between 0.25 and 0.5 m² who need cardiac surgery with cardiopulmonary bypass. Urgent and norwood procedures are excluded.