Comparison of pulmonary artery and transpulmonary thermodilution cardiac output measurements in unsedated newborn calves

Comparison of Transpulmonary Thermodilution and Calibrated Pulse Contour Analysis with Pulmonary Artery Thermodilution Cardiac Output Measurements in Anesthetized Dogs

“…Although some studies have defined that the acceptable PE of the new method should be ≤30% if it is to be used clinically in replacement for the reference standard, this criterion was not adopted in the present study. The use of a predefined PE as a benchmark to determine the interchangeability between the test and the reference methods of CO measurement assumes that the precision of the test method (POM TEST ) should be at least equal to the precision of the reference method (POM REF ).…”

“…Considering the acceptable PE of ≤30% as a benchmark to determine the interchangeability between methods of CO measurement, TPTD CO and PCA CO would be considered interchangeable with PATD CO in the present report. However, the 30% limit is estimated from the precision of single PATD CO measurements as the reference method (20%) and was incorrectly used in studies where PATD CO was averaged from triplicate measurements . The error of PATD CO can be substantially smaller if values are averaged from repeated measurements and if there is a strict control of factors that increase the variability of repeated PATD CO measurements (absence of arrhythmias, cardiovascular stability, constant injectate temperature, and volume).…”

“…Significant CO overestimation might also occur with lower volumes of thermal indicator because of decreased signal-to-noise ratio. Although the agreement between PATD CO and TPTD CO has been studied in humans, [7][8][9][10][11] pigs, 12 calves, 13 cats, 14,15 and dogs, 16,17 objective interpretation of these reports is difficult because of the absence of clearly defined criteria to determine the clinically acceptable bias and limits of agreement (LOA) between PATD CO and TPTD CO . Calibrated pulse contour analysis (PCA CO ) provides continuous CO estimations based on beat-to-beat variations in stroke volume calculated from complex analysis of the systolic portion of the arterial pressure waveform.…”

“…Significant CO overestimation might also occur with lower volumes of thermal indicator because of decreased signal‐to‐noise ratio. Although the agreement between PATD CO and TPTD CO has been studied in humans, pigs, calves, cats, and dogs, objective interpretation of these reports is difficult because of the absence of clearly defined criteria to determine the clinically acceptable bias and limits of agreement (LOA) between PATD CO and TPTD CO .…”