Right ventricular stroke volume assessed by pulmonary artery pulse contour analysis

Abstract

Background Stroke volume measurement should provide estimates of acute treatment responses. The current pulse contour method estimates left ventricle stroke volume. Heart-lung interactions change right ventricular stroke volume acutely. We investigated the accuracy, precision, and trending abilities of four calibrated stroke volume estimates based on pulmonary artery pulse contour analysis. Results Stroke volume was measured in 9 pigs with a pulmonary artery ultrasound flow probe at 5 and 10 cmH2O of PEEP and three volume states (baseline, bleeding, and retransfusion) and compared against stroke volume estimates of four calibrated pulmonary pulse contour algorithms based on pulse pressure or pressure integration. Bland-Altman comparison with correction for multiple measurements and trend analysis were performed. Heart rate and stroke volumes were 104 ± 24 bpm and 30 ± 12 mL, respectively. The stroke volume estimates had a minimal bias: − 0.11 mL (95% CI − 0.55 to 0.33) to 0.32 mL (95% CI − 0.06 to 0.70). The limits of agreement were − 8.0 to 7.8 mL for calibrated pulse pressure to − 10.4 to 11.5 mL for time corrected pressure integration, resulting in a percentage error of 36 to 37%. The calibrated pulse pressure method performed best. Changes in stroke volume were trended very well (concordance rates 73–100%, r2 0.26 to 0.987, for pulse pressure methods and 71–100%, r2 0.236 to 0.977, for integration methods). Conclusions Pulmonary artery pulse contour methods reliably detect acute changes in stroke volume with good accuracy and moderate precision and accurately trend short-term changes in cardiac output over time.

Impact of respiratory cycle during mechanical ventilation on beat-to-beat right ventricle stroke volume estimation by pulmonary artery pulse wave analysis

“…Newer monitoring devices, which incorporate algorithms to estimate SV and CO from PA PWA , also fall short as they calculate these values over extended time periods rather than on the precise scale of cardiac cycles; therefore, they do not allow evaluation of beat-by-beat variability nor the effect of breathing on SV. Previous experimental studies have shown the possibility of detecting short-term changes in SV with PA pulse contour but a low beat-by-beat correlation with the reference method [ 3 ]. While echocardiography and Doppler techniques do offer beat-scale estimations of RVSV, their intermittent nature precludes their feasibility for continuous monitoring.…”

“…Estimation of left ventricle stroke volume (SV) through systemic arterial pulse wave analysis [ 1 ] is widely accepted in clinical practice [ 2 ]. The physiological principles used to estimate SV from arterial pulse wave analysis in the systemic circulation can also be applied to the pulmonary artery (PA) [ 3 ] to estimate the right ventricle (RV) SV (RVSV). Recent studies have underscored the role of RV and pulmonary circulation during hemodynamic instability situations [ 4 , 5 ].…”

Cardiopulmonary interactions—which monitoring tools to use?

“…A shortcoming of the PAC—stemming from the thermodilution technique - is its inability to report immediate changes in stroke volume. However, pulmonary pulse contour analysis with direct assessment of RV stroke volume is feasible ( Berger et al, 2020 ) and this limitation may be overcome by advanced PAC models with shorter thermodilution response times ( Bootsma et al, 2022 ).…”