Combined Central Venous Oxygen Saturation and Lactate as Markers of Occult Hypoperfusion and Outcome Following Cardiac Surgery

Objective To assess the association between postoperative central venous oxygen saturation (ScvO 2 ) and arterial lactate with outcome after cardiac surgery. Design Prospective observational study. Setting University-affiliated tertiary care hospital. Participants Patients after coronary artery bypass and/or valve surgery. Interventions None. Measurements and Main Results Postoperative ScvO 2 and arterial lactate were obtained on arrival to the intensive care unit (ICU). ScvO 2 and lactate were drawn again at 8 and 24 hours, respectively, after ICU admission. Moderate global tissue hypoxia (GTH) was defined as ScvO 2 2 2 on ICU admission negatively correlated with postoperative 24-hour lactate ( p = 0.009), which was a strong predictor of time on mechanical ventilation, total complications, and ICU and hospital lengths of stay ( p p = 0.04) and a trend toward longer length of mechanical ventilation ( p = 0.17) and number of complications per patient ( p = 0.09) compared with those without GTH (n = 10). Conclusions The incidence of GTH is high after cardiac surgery. Postoperative ScvO 2 and lactate may be valuable measurements to identify patients with occult hypoperfusion and subsequently guide hemodynamic optimization to positively affect postoperative outcomes in patients after cardiac surgery.