Key result
The ProAQT system provided inaccurate absolute cardiac output measurements compared to transpulmonary thermodilution in major cardiac surgery patients, with a mean bias of -0.31 L/min for radial and -0.57 L/min for femoral access.
Why the study?
Does the Pulsioflex-ProAQT system accurately measure cardiac output and track fluid responsiveness compared to transpulmonary thermodilution in major cardiac surgery patients?
Observational (n=25)
No
Does the Pulsioflex-ProAQT system accurately measure cardiac output and track fluid responsiveness compared to transpulmonary thermodilution in major cardiac surgery patients?
The ProAQT system provides inaccurate absolute cardiac output measurements compared to thermodilution in major cardiac surgery patients, but can reliably track fluid responsiveness.
ProAQT absolute cardiac output values warrant caution in cardiac surgery patients; observational data leaves open validation for trend monitoring.
BACKGROUND: A relatively new uncalibrated arterial pressure waveform cardiac output (CO) measurement technique is the Pulsioflex-ProAQT® system. Aim of this study was to validate this system in cardiac surgery patients with a specific focus on the evaluation of a difference in the radial versus the femoral arterial access, the value of the auto-calibration modus and the ability to show fluid-induced changes. METHODS: In twenty-five patients scheduled for ascending aorta, aortic arch replacement, or both we measured CO simultaneously by transpulmonary thermodilution (COtd) and by using the ProAQT® system connected to the radial (COpR), as well as the femoral artery catheter (COpF). Hemodynamic data were assessed at predefined time points; from incision until 16 h after ICU admission. RESULTS: In total 175 (radial) and 179 (femoral) pairs of CO measurement were collected. The accuracy of COpR/COpF was evaluated showing a mean bias of -0.31 L/min (±2.9 L/min) and -0.57 L/min (± 2.8 L/min) with percentage errors of 49 and 46% respectively. Trending ability of the ProAQT® device was evaluated; the four quadrant concordance rates in the radial and femoral artery were 74 and 75% and improved to 77 and 85% after auto-calibration. The mean angular biases in the radial and femoral artery were 6.4° and 6.0° and improved to 5° and 3.3° after auto-calibration. The polar concordance rates in the radial and femoral artery were 65 and 70% and improved to 76 and 84% after auto-calibration. Considering the fluid-induced changes in stroke volume(SV), the coefficient of correlation between the changes in SVtd and SVp was 0.57 (p < 0.01) in the radial artery and 0.60 (p < 0.01) in the femoral artery. CONCLUSIONS: The ProAQT® system can be of additional value if the clinician wants to determine fluid responsiveness in cardiac surgery patients. However, the ProAQT® system provided inaccurate CO measurements compared to transpulmonary thermodilution. The trending ability was poor for COpR but moderate for COpF. Auto-calibration of the system did not improve accuracy of CO measurements nor did it improve the prediction of fluid responsiveness. However, the trending ability was improved by auto-calibration, possibly by correcting a drift over a longer time period.
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Drumpt et al. (2017) conducted an observational in Major cardiac surgery (n=25). ProAQT system (arterial pressure waveform cardiac output measurement) vs. Transpulmonary thermodilution (PiCCO system) was evaluated on Accuracy of cardiac output measurement (mean bias) (MD -0.31 L/min). The ProAQT system provided inaccurate absolute cardiac output measurements compared to transpulmonary thermodilution in major cardiac surgery patients, with a mean bias of -0.31 L/min for radial and -0.57 L/min for femoral access.
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