Continuous cardiac output by femoral arterial thermodilution calibrated pulse contour analysis: comparison with pulmonary arterial thermodilution.
OBJECTIVE
To compare two thermodilution methods for the determination of cardiac output (CO)-thermodilution in the pulmonary artery (COpa) and thermodilution in the femoral artery (COa)-with each other and with CO determined by continuous pulse contour analysis (COpc) in terms of reproducibility, bias, and correlation among the different methods. Good agreement between the methods would indicate the potential of pulse contour analysis to monitor CO continuously and at reduced invasiveness.


METHODS
Prospective criterion standard study.


METHODS
Cardiac surgical intensive care unit in a university hospital.


METHODS
Twenty-four postoperative cardiac surgery patients.


METHODS
Without interfering with standard hospital cardiac recovery procedures, changes in CO as a result of the postsurgical course, administration of vasoactive substances, and/or fluid administration were recorded. CO was first recorded after a 1-hr stabilization period in the intensive care unit and hourly thereafter for 6 hrs, and by subsequent determinations at 9, 12, and 24 hrs.


RESULTS
There were 216 simultaneous determinations of COpa, COa, and COpc. COpc was initially calibrated using COa, and no further recalibration of COpc was performed. COpa ranged from 3.0 to 11.8 L/min, and systemic vascular resistance ranged from 252 to 2434 dyne x sec/cm5. The mean difference (bias) +/-2 SD of differences (limits of agreement) was -0.29+/-1.31 L/min for COpa vs. COa, 0.07+/-1.4 L/min for COpc vs. COpa, and -0.22+/-1.58 L/min for COpc vs. COa. In all but four patients COpc correlated with COa after the initial calibration. Correlation and precision of COpc vs. COa was stable for 24 hrs.


CONCLUSIONS
Femoral artery pulse contour CO correlates well with both COpa and COa even during substantial variations in vascular tone and hemodynamics. Additionally, CO determined by arterial thermodilution correlates well with COpa. Thus, COa can be used to calibrate COpc.
Goedje
O
O
Department of Cardiac Surgery, Ludwig-Maximillians-University of Munich, Germany. oliver.goedje@medizin.uni-ulm.de
Hoeke
K
K
Lichtwarck-Aschoff
M
M
Faltchauser
A
A
Lamm
P
P
Reichart
B
B
D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity; D001794:Blood Pressure; D002302:Cardiac Output / Q000502:physiology*; D006348:Cardiac Surgical Procedures; D002406:Catheterization, Peripheral; D003325:Coronary Care Units; D005260:Female; D005263:Femoral Artery / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D015588:Observer Variation; D011446:Prospective Studies; D011651:Pulmonary Artery / Q000502:physiology; D015203:Reproducibility of Results; D013815:Thermodilution / Q000379:methods; D014655:Vascular Resistance