Abstract

S. D. Divya Prakash, Z. Basel, S. Sohi Kowsar, V. Prathima, Dr. S. Ooha, Dr. Ananda Bhat*

ABSTRACT

Background: Central venous oxygen saturation (ScvO?) reflects the balance between systemic oxygen delivery and consumption and may detect occult hypoperfusion during coronary artery bypass grafting (CABG). However, prognostic thresholds remain insufficiently defined in Indian cohorts. Methods: In this prospective observational study, 100 adults undergoing elective CABG were evaluated at a tertiary cardiac center. ScvO? was measured intraoperatively and postoperatively and categorized as Low (<60%), Normal, or High. Concurrent lactate levels, ejection fraction (EF), and Mini-Mental State Examination (MMSE) scores were recorded. Associations with morbidity, mortality, and postoperative ICU utilization were assessed using chi-square testing and multinomial logistic regression. Results: Low ScvO? (<60%) was significantly associated with mortality (p = 0.001), postoperative EF reduction (p = 0.038), complications (p = 0.006), intra-aortic balloon pump requirement (p = 0.024), elevated lactate levels (p < 0.001), and increased postoperative care demands (p = 0.004). High lactate levels (OR 15.2, p = 0.002), postoperative complications (OR 7.0, p = 0.005), and mortality (OR ≈0.0004, p < 0.001) independently predicted low ScvO?. Conclusion: ScvO? values below 60% independently predicted adverse perioperative outcomes after CABG and showed improved prognostic value when combined with lactate. ScvO? monitoring is a practical, cost-effective tool for perioperative risk stratification in resource-limited settings.