Objective: To evaluate and compare monitors of cardiac output during repositioning and stabilization of the heart for off-pump coronary artery bypass (OPCAB) surgery. Design: Prospective, observational, clinical study. Setting: University teaching hospital. Participants: Consecutive patients scheduled to undergo elective OPCAB (n = 19). Interventions: Monitoring, induction, and anesthesia followed a routine protocol for coronary artery bypass patients. This included the use of transesophageal echocardiography (TEE) and pulmonary artery catheter placement. Measurements and Main Results: After positioning and stabilization for OPCAB surgery, the changes in descending aortic flow velocity (VTI) times heart rate (HR) and the mixed venous oxygen saturation (SvO2) could be used to predict the changes in thermodilution cardiac output (TDCO) using the following model: ΔTDCO (calc) = -13.15 + 0.35 (ΔVTI*HR) + 0.61 (ΔSvO 2) where Δ indicates the percentage change from baseline values. The changes in mean arterial pressure, mean pulmonary artery pressure, and continuous cardiac output did not correlate with the changes in TDCO. Conclusion: The use of the VTI*HR, as determined by TEE, in addition to the SvO2 can strengthen clinical decision making during repositioning and stabilization of the heart during OPCAB. Changes in the VTI*HR and SvO2 can be used as surrogate markers for changes in CO during OPCAB surgery.
- Cardiac output
- Cardiac surgery
- Transesophageal echocardiography
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine