Continued Ventilation During Cardiopulmonary Bypass

Cardiopulmonary bypass (CPB) is well known to induce a strong anti-inflammatory response. The investigators examined whether continued mechanical ventilation during CPB alters systemic immune activation.

Cardiopulmonary bypass is well known to induce a strong anti-inflammatory response. Studies had been shown that the contact of blood components with artificial surfaces, the surgical trauma, endotoxemia and a reperfusion injury are in part responsible for the seen immunological affect after surgery. The purpose of this study is to test the effect of continued mechanical ventilation during surgery on a blood marker called soluble ST2 in patients sera. Soluble ST2 acts as a decoy receptor of IL-33 and has anti-inflammatory effects. Elevated soluble ST2 concentrations are reported in patients with acute myocardial infarction, sepsis, congestive heart failure and elevates soluble ST2 levels are associated with adverse outcome.

In the non-ventilated group lungs were collapsed after completion of CPB until after weaning from the extracorporeal circulation.

In the ventilated group, mechanical ventilation was done with the half of the initial tidal volume (i.e. 3-4 ml/kg, 250-300ml) during the aortic cross-clamp.

. In the non-ventilated group lungs were collapsed after completion of CPB until after weaning from the extracorporeal circulation.

Concentration of soluble ST2 will be assessed in the serum of patient´s preoperativem, postoperative and the following five consecutive days after surgery.

Inclusion Criteria: Written informed consent age > 40 and < 80 Exclusion Criteria: treatment with steroids or immunomodulatory interventions during the past four weeks signs of an acute infection

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