Cardiac intensivist UAB Birmingham, Alabama, United States
Abstract:
Introduction: Lung injury is an expected complication following cardiopulmonary bypass (CPB). Identifying specific biological molecules related to post-CPB lung injury could help us better diagnose, predict and potentially impact our patient’s clinical course after cardiac surgery. We identified Proteoglycan 4 (PRG4) as potential biomarker for patients with prolonged mechanical ventilation following CPB in a small pilot study using unbiased proteomic analysis.
Objectives: We hypothesize that pediatric patients with acute lung injury following cardiac surgery have lower serum levels of PRG4. To validate our prior findings, we propose measuring PRG4 levels in plasma at different time points (pre-surgery and 48 hours post-surgery) in a larger cohort of patients with prolonged mechanical ventilation and compare it to patients with limited use of mechanical ventilation following surgery. Method Infant with cardiac defect (Tetralogy, ventricular septal defect, atrioventricular defect) who underwent surgical repair from 2012 to 2020 with stored plasma samples in our repository were screened for inclusion. Patients with mechanical ventilation before surgery were excluded. Included patients were divided in tertiles in regards to their mechanical ventilation duration. Control group included patients in the first tertile while study group included patients in the third tertile group. Preoperative and 48-hour postoperative plasma samples for 20 patients in each group assayed for PRG4 level by ELISA technique, using full length recombinant human PRG4 for the standard . Clinical and laboratory variables were collected retrospectively.
Results: Patients in the study group were younger and had smaller weight at time of surgery. The length of CPB and aortic cross clamp time were statistically indifferent. PRG4 levels in plasma before surgery and 48 hours after surgery were lower in the study group compared to the control group (p=0.02, p=0.002). PRG4 levels before and after surgery were similar in the control group. PRG4 levels after surgery were lower compared to before surgery in the study group but statistically insignificant (P=0.086).
Conclusion: Lower levels of plasma PRG4 can predict longer duration of mechanical ventilation following cardiac surgery. Further validation of this finding in a larger and more diverse cohort is necessary prior to its application at the bedside.
