Clinical Validation of Pulse Contour and Pulse Wave Transit Time-Based Continuous Cardiac Output Analyses in Thai Patients Undergoing Cardiac Surgery
Petch Wacharasint MD*1, Pimsai Kunakorn MD*1, Pimporn Pankongsap MD*1, Ratanachai Preechanukul MD*1
Affiliation : *1 Department of Anesthesiology, Phramongkutklao Hospital, Bangkok, Thailand
Objective : To evaluate the performance of arterial pressure-based cardiac output (APCO) and pulse wave transit time-based
cardiac output (esCCO) monitors in Thai patients undergoing cardiac surgery with cardiopulmonary bypass.
Material and Method: The authors studied fifty Thai surgical patients undergoing coronary artery bypass graft surgery
(CABG) with cardiopulmonary bypass and requiring pulmonary artery catheters and radial artery catheter placement as a
standard of clinical care. All patients were measured for APCO using the Vigileo/FloTracTM and esCCO using the esCCOTM
monitoring system. The data were compared to thermodilution cardiac output (TDCO) monitoring as a reference method,
simultaneously at pre-induction of anesthesia, post-induction, and every 30 minutes thereafter until the completion of the
surgery. The bias and precision were assessed using Bland-Altman analysis.
Results : 310 pairs of simultaneous measurements of APCO vs. TDCO and 303 pairs of esCCO vs. TDCO were obtained
from fifty patients. Both APCO (R = 0.53, p<0.0001) and esCCO values (R = 0.56, p<0.0001) were correlated with TDCO
values. Either of the changes in APCO (R = 0.63, p<0.0001) or any changes in esCCO (R = 0.60, p<0.0001) were correlated
with changes in TDCO. For APCO relative to TDCO, the bias, precision, and the limits of agreement were 0.70, +1.63, and
-2.5 to 3.9 L/min while of esCCO were 1.20, +1.59, and -1.9 to 4.3 L/min, respectively. Comparisons of the bias of APCO and
esCCO revealed a level of significance of p<0.001.
Conclusion : Despite the overestimation of CO measurements, APCO and esCCO calibrated with patient information has
shown an acceptable trend as compared to TDCO in Thai patients undergoing CABG with cardiopulmonary bypass.
Compared to esCCO, APCO demonstrated no significant differences of precision however; a lower mean bias was exhibited.
Keywords : Pulse wave transit time, Pulse contour, Cardiac output
