Abstract
A pulse-contour-based method for continuous measurement of cardiac Output (CO) and
systemic vascular resistance (SVR) was tested and arterial thermodilution, used for
calibration, was compared to pulmonary artery thermodilution. In 30 patients CO and
SVR were measured by pulse contour analysis (COpc, SVRpc) 270 times in 24 h and compared
to arterial (COart, SVRart) and pulmonary arterial (COpa, SVRpa) thermodilution measurements.
The mean difference between COpa and COart was 0.26 L/min (3.6%) with a Standard deviation
(SD) of 0.7 L/min, the correlation coefficient was 0.96, and the coefficient of Variation
was 5.0% and 5.9% respectively. COpc did differ from COpa by 0.11 L/min (1.5%, SD
= 0.6L/min) and from COart by 0.15 L/min (2.1 %, SD = 0.7 L/min). Correlation of COpc
with COpa was 0.91, correlation of COpc with COart was 0.90. SVRpc did correlate with
SVRpa, a coefficient of 0.94, and with SVRart, a coefficient of 0.92. Mean COpc and
SVRpc did not differ significantly from COpa or COart and SVRpa or SVRart during the
24 h study period. It is concluded that COart correlates well with COpa and can be
used to calibrate COpc. COpc and SVRpc agree with thermodilution-based CO and SVR
without recalibration for 24 hours.
Key words
Thermodilution - Cardiac Output - Cardiac surgery - Pulse contour analysis - Intensive
care medicine
