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.