Esophageal Doppler and thermodilution are not interchangeable for determination of cardiac output

Area of Science:

• Cardiovascular Surgery
• Anesthesiology
• Hemodynamics

Background:

• Accurate cardiac output monitoring is crucial during off-pump coronary artery bypass (OPCAB) surgery.
• Thermodilution cardiac output (TD-CO) and esophageal Doppler cardiac output (ED-CO) are commonly used methods.
• Assessing their interchangeability during OPCAB is essential for clinical decision-making.

Purpose of the Study:

• To compare the agreement between TD-CO and ED-CO during hemodynamic stability and after heart stabilization in OPCAB surgery.
• To determine if TD-CO and ED-CO are interchangeable during various stages of OPCAB procedures.

Main Methods:

• Simultaneous TD-CO and ED-CO measurements were taken in 58 patients undergoing OPCAB.
• Measurements were recorded at four time points: post-probe insertion, before/after heart displacement, and before sternal closure.
• Data were analyzed using the Bland and Altman method to assess bias and agreement.

Main Results:

• A total of 302 paired measurements were analyzed.
• The degree of agreement (bias +/- 2 SD) was within the interchangeable limit (< 0.5 L.min(-1)) only at the initial measurement point (T0).
• At subsequent time points, the agreement between TD-CO and ED-CO exceeded the interchangeable threshold.

Conclusions:

• Thermodilution cardiac output and esophageal Doppler cardiac output are not interchangeable during OPCAB surgery.
• The lack of agreement suggests that these methods provide different hemodynamic information during this surgical context.
• Clinical use of these devices should consider their limitations and potential lack of interchangeability in OPCAB procedures.