Abstract
BACKGROUND: Effective evacuation of shed blood around the heart and lungs is essential in the early postoperative period following cardiac surgery. Incomplete evacuation can lead to retained blood syndrome (RBS), which may necessitate reintervention. This study aimed to determine the incidence of RBS requiring reintervention and assess its impact on early clinical outcomes. METHODS: We conducted a prospective, cross-sectional observational study including all adult patients undergoing cardiac surgery between January 1, 2022, and June 30, 2024. Patients who underwent procedures for retained blood were compared to those who did not. Univariate and multivariate analyses were used to evaluate the impact of RBS on postoperative outcomes. RESULTS: Among 330 enrolled patients, 49 (14.8%) underwent a total of 65 reintervention procedures (19.5%) for removal of retained blood from the pericardial or pleural spaces. RBS was associated with an increased hospital stay > 11 days (OR 1.379; 95% CI 1.255-1.519; p < 0.001), ICU stay > 2 days (OR 1.035; 95% CI 1.020-1.050; p < 0.001), and ventilation time > 4 h (OR 1.158; 95% CI 1.078-1.244; p < 0.001). There was no statistically significant difference in postoperative mortality between the two groups. RBS was an independent predictor of postoperative pulmonary complications (26.5.6% vs. 5.7%, OR 0.167, 95% CI 0.74 - 0.376), deep sternal wound infection or mediastinitis (20.4% vs. 3.9%, OR 0.159, 95% CI 0.063-0.399), and postoperative renal impairment (16.3% vs. 5.3%, OR 0.289, 95% CI 0.115-0.724). CONCLUSIONS: Retained blood after cardiac surgery is common and significantly associated with prolonged ICU and hospital stays, increased ventilator time, and higher rates of postoperative complications. Early recognition and appropriate management may improve outcomes.