Immune Responses and Pulmonary Complications After Cardiac Surgery With Cardiopulmonary Bypass

Cardiac surgery under cardiopulmonary bypass (CPB) is associated with a high incidence of postoperative pulmonary complications (PPCs; 10% to 30% incidence). Ranging from atelectasis to acute respiratory syndrome, PPCs are associated with increased hospital length of stay and mortality. Cardiac surgery with CPB induces a complex pathophysiological response characterized by ischemia-reperfusion, activation of the contact system and hypoventilation. The individual immune and inflammatory response may contribute to the development of PPCs. Exploring the association between immuno-inflammatory response and post-operative clinical outcomes might enable a better understanding of the mechanism associated with PPCs and contribute to a more personalized approach to patient care. This prospective observational cohort study will enroll 100 adult patients scheduled for elective cardiac surgery with CPB. The primary objective of this research is to investigate the association between the perioperative immuno-inflammatory profile and the occurrence of PPCs within the first seven days following cardiac surgery under CPB. To identify these profiles, blood and bronchoalveolar lavage samples will be collected at 5 (T0 -T4) and 2 (T0-T1) different times respectively. Multiple biological analyses (RNA single cell, proteomics, flow cytometry, cell culture experiments) will be performed to characterize the immune and inflammatory response to the surgery. PPCs are defined as atelectasis associated with hypoxemia (PaO2/FiO2 \< 200), pneumonia or acute respiratory distress syndrome. The study hypothesis is that patients who develop PPCs have a different immune and inflammatory response to cardiac surgery with CPB.