Cardiac output--pulse contour analysis vs. pulmonary artery thermodilution

Area of Science:

• Cardiovascular physiology
• Hemodynamic monitoring
• Critical care medicine

Background:

• Accurate cardiac output (CO) measurement is crucial for hemodynamic management.
• Pulmonary artery thermodilution (PA-TD), transpulmonary thermodilution (TP-TD), and pulse contour analysis (PCA) are methods used for CO assessment.
• Evaluating the agreement and tracking ability of these CO monitoring techniques is essential for clinical application.

Purpose of the Study:

• To compare the agreement between PA-TD, TP-TD, and PCA for CO measurement.
• To assess the ability of PCA to track changes in CO during interventions.
• To determine the precision and bias of these CO monitoring methods.

Main Methods:

• CO was measured using PA-TD and TP-TD before cardiac surgery in 25 patients.
• Post-operatively, CO was measured using PA-TD and PCA.
• Hemodynamic changes induced by atrial pacing were monitored using PA-TD and PCA in patients with low heart rate or cardiac index.

Main Results:

• PA-TD and TP-TD demonstrated similar precision (0.41 vs. 0.48 L/min).
• TP-TD overestimated CO by 0.46 L/min compared to PA-TD.
• Post-operative agreement between PA-TD and PCA was poor (bias 0.07 L/min, limits of agreement +/- 2.20 L/min).
• PCA successfully tracked pacing-induced CO changes in 15 out of 16 patients.

Conclusions:

• PA-TD and TP-TD offer comparable precision for CO measurement, though TP-TD shows a slight overestimation.
• Post-operative CO measurements by PA-TD and PCA lack agreement.
• PCA demonstrates reliability in tracking dynamic changes in CO, despite absolute value discrepancies.