Intraoperative optimization of hemodynamic parameters is associated with a better outcome after cardiac surgery

Introduction

Goal-directed therapy has been used for critically ill patients. The purpose of this study was to evaluate the ability of intraoperative perfusion parameters in predicting outcome after cardiac surgery.

Methods

A total of 98 patients undergoing cardiac surgery were prospectively evaluated. Samples of lactate, arterial gases, and central venous saturation (SVO₂) were collected 60 minutes after beginning surgery, 120 minutes after and at the end of the procedure. Univariate and multivariate analyses were performed.

Results

Factors associated with cardiac dysfunction were previous low ejection fraction (P = 0.035), surgery with pump (P = 0.001), longer duration of pump (P = 0.003), low initial intra-operative central venous saturation (P = 0.001) and high level of initial gapCO₂ (P = 0.02). A low intraoperative SVO₂ was independently associated with a sevenfold increase (95% CI, 2–21) and a initial high level of CO₂gap with a 4.5-fold increase (95% CI, 1.6–12) in cardiac dysfunction after cardiac surgery. Associated factors with renal dysfunction were age (P = 0.045), longer duration of pump (P = 0.01) and low initial intraoperative central venous saturation (P = 0.001). A low intraoperative SVO₂ was associated with a 12-fold increase and a low level of initial base excess with a 27-fold increase in rates of infection after cardiac surgery. A high level of final arterial lactate predicted a longer time of mechanical ventilation (OR, 4.56; 95% CI, 1.4–11.2). There were no relations of perfusion parameters with longer time of stay in the ICU or mortality.

Conclusion

In this observational study, a low intraoperative level of SVO₂ is an independent predictor of cardiac dysfunction, renal failure and infection after cardiac surgery and a high level of lactate is associated with a longer time of mechanical ventilation. These findings suggest that these parameters may be markers of prognosis after cardiac surgery.