2.3. Pericardial fluid and blood sample collection
Before and after on the CPB, we collected venous blood samples from all patients. The collected samples were centrifuged at 1500 g for 10 min at 4 °C and stored at −80 °C until analysis. In addition, after median sternotomy was performed with standard CPB procedures, the pericardium was opened and the pericardial fluid (PF) was aspirated with a sterile syringe. The aspirated PF (2-5 mL) was then taken into sterile tubes without anticoagulant and placed in an ice-filled container. Afterward, the samples were centrifuged (At 2500 g for 5 min at 4 °C) 2 times and the supernatant phase was separated. Supernatants were stored in RNase-free tubes at -80 °C until assayed. Albumin levels in plasma and PF samples were measured by the biuret method.