Continuous postoperative pericardial flushing to reduce the risk of postoperative bleeding after elective adult cardiac surgery - a study-level meta-analysis.

Background: Retained blood syndrome contributes to higher morbidity and mortality post cardiac surgery. We investigate the benefits of continuous postoperative pericardial flushing (CPPF) over standard care chest drainage in elective adult cardiac surgery patients.

Methods: Various online databases were screened for randomised controlled trials (RCTs) and observations studies comparing CPPF to standard care.

Primary outcomes: 12-hour and total blood loss, cardiopulmonary bypass (CPB) and aortic cross-clamp (ACC) times; surgical re-intervention for bleeding, mortality, sternal wound infections and pericardial or pleural fluid re-accumulation at discharge.

Secondary outcomes: perioperative blood transfusion, time to extubation and total hospital stay.

Results: 586 patients from four studies with matched characteristics were included. CPPF was associated with less blood loss at 12 h and in total: Odds Ratio (OR) (95% CI) 0.71 (-0.91 to 0.51) and 0.49 (-0.67 to -0.32) (both p < 0.00001). CPPF had lower need for transfusion of blood products RR 0.57 (0.36-0.89) (p = 0.01)). There were no significant differences in surgical re-intervention rates, overall mortality, CPB, ACC times, length of hospital stay, time until extubation or sternal wound infections. Risk of pericardial or pleural fluid re-accumulation was lower in the CPPF groups RR 0.88 (0.80-0.97) (p = 0.01).

Conclusions: CPPF has shown promising results in reducing postoperative blood loss and fluid re-accumulation with fewer blood transfusions, and lower surgical re-intervention rates across all ranges of cardiac surgical procedures. It is safe, feasible and effective in all types of cardiac surgery, however further studies are needed to validate these findings.