The Application of Oxygen Saturation of Central Venous Blood (ScVO2) in Complicated Acute Coronary Syndrome as a Probable Disease Monitor A Pilot Study

Background: The oxygen saturation of the central vein (ScVO2) has been regarded as a surrogate of tissue perfusion in patients of severe sepsis and major surgery. However, ScVO2 in acute coronary syndrome has not been addressed. We tried to delineate the trend of ScVO2 in patients of acute coronary syndrome. Methods and Patients: This was a prospective observational study in the coronary care unit of a medical center. Patients of acute coronary syndrome with acute lung edema or cardiogenic shock were enrolled. Blood samples from central vein (via 3-lumen catheter in superior vena cava) and peripheral artery immediately after admission, 24 and 48 hours later were analyzed by co-oxymetry method. The primary endpoint was “event-fatality”. The secondary endpoint was in-hospital all-cause mortality. Results: Forty-three patients were enrolled in the period of 3 months. There were 5 event-fatality (event-fatality rate: 11.6 ). The non-survivors had lower event-ScVO2 (39.4 12.9 , median 44.5 ), while the survivors had higher event-ScVO2 of 65.6 9.9 (median 66.2 ) (p < 0.05). The APACHE II score (27.8 8.8, median 30.5 vs. 17.4 6.3, median 18, p < 0.05) and TISS score (51 22.4, median 51, vs. 44 13.7 median 42.5, p < 0.05) showed the same trend. The time series of ScVO2 implicated heterogeneity during the course, but the overall trend showed increment of ScVO2 as the disease improved. Conclusion: ScVO2 could reflect the disease process of a complicated acute coronary syndrome. It should be one of the integral indices of tissue perfusion in critical patients of primary cardiac events, and it is more practical and accessible than mixed venous oxygen saturation.