Estimation of cardiac output in a pharmacological trial using a simple method based on arterial blood pressure signal waveform: a comparison with pulmonary thermodilution and echocardiographic methods.
OBJECTIVE
Cardiac output (CO) has traditionally been measured using invasive techniques, which involve an element of risk. Thus, a reliable less-invasive method for determining CO would be very valuable for research use. We tested whether simple analysis of the arterial pulse waveform, not requiring large-vessel catheterisation or expensive equipment, could provide an estimate of CO that is accurate enough for pharmacological studies.


METHODS
We measured CO in 11 healthy male subjects who received low and high doses of dexmedetomidine (alpha2-adrenoceptor agonist), using pulse contour analysis, echocardiography and pulmonary thermodilution techniques.


RESULTS
At baseline, these methods gave the following mean (SD) values of CO: 6.18 (1.59), 5.22 (1.35) and 7.03 (1.54) l/min, respectively. High-dose dexmedetomidine reduced CO to 4.50 (0.68), 3.65 (0.65) and 4.80 (0.89) l/min, corresponding to -25 (14) %, -28 (12) % and -30 (14) % reductions from baseline, respectively. The pulse contour method described these dexmedetomidine-induced changes in CO very similarly to the thermodilution and echocardiographic methods. The limits of agreement [bias (2SD)] were 0.55 (2.55) and -0.10 (2.04) l/min, respectively.


CONCLUSIONS
The minimally invasive pulse contour analysis technique might be suitable for pharmacological studies for the detection of major drug-induced reductions in CO.
Penttilä
Jani
J
Turku PET Centre, Turku University Central Hospital, Turku, Finland.
Snapir
Amir
A
Kentala
Erkki
E
Koskenvuo
Juha
J
Posti
Jussi
J
Scheinin
Mika
M
Scheinin
Harry
H
Kuusela
Tom
T
D000316:Adrenergic alpha-Agonists / Q000008:administration & dosage; D000328:Adult; D002302:Cardiac Output / Q000187:drug effects; D020927:Dexmedetomidine / Q000008:administration & dosage; D015150:Echocardiography, Doppler / Q000379:methods; D006334:Heart Function Tests / Q000379:methods / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D013815:Thermodilution / Q000379:methods
D000316:Adrenergic alpha-Agonists; D020927:Dexmedetomidine