Monitoring Cardiac Output Trends With End-Tidal Carbon Dioxide Pressures in Off-Pump Coronary Bypass

The optimum method of intraoperative monitoring in patients undergoing off-pump coronary bypass remains debatable. Using capnography and end-tidal carbon dioxide pressure may be a helpful method of monitoring cardiac output trends, especially when grafting posterior and lateral vessels. After repositioning the heart, Endtidal carbon dioxide pressures that continue to trend down usually indicate decreased cardiac output and precede hemodynamic and electrical instability. The advantages of this method include simplicity, universal availability, and a short response time to changes in cardiac output. (Ann Thorac Surg 2011; 91: e81-2) (C) 2011 by The Society of Thoracic Surgeons