Arterial pressure-based cardiac output in septic patients: different accuracy of pulse contour and uncalibrated pressure waveform devices.
BACKGROUND
We compared the ability of two devices estimating cardiac output from arterial pressure-curve analysis to track the changes in cardiac output measured with transpulmonary thermodilution induced by volume expansion and norepinephrine in sepsis patients.


METHODS
In 80 patients with septic circulatory failure, we administered volume expansion (40 patients) or introduced/increased norepinephrine (40 patients). We measured the pulse contour-derived cardiac index (CI) provided by the PiCCO device (CIpc), the arterial pressure waveform-derived CI provided by the Vigileo device (CIpw), and the transpulmonary thermodilution CI (CItd) before and after therapeutic interventions.


RESULTS
The changes in CIpc accurately tracked the changes in CItd induced by volume expansion (bias, -0.20 +/- 0.63 L/min/m2) as well as by norepinephrine (bias, -0.05 +/- 0.74 L/min/m2). The changes in CIpc accurately detected an increase in CItd >or= 15% induced by volume expansion and norepinephrine introduction/increase (area under ROC curves, 0.878 (0.736 to 0.960) and 0.924 (0.795 to 0.983), respectively; P < 0.05 versus 0.500 for both). The changes in CIpw were less reliable for tracking the volume-induced changes in CItd (bias, -0.23 +/- 0.95 L/min/m2) and norepinephrine-induced changes in CItd (bias, -0.01 +/- 1.75 L/min/m2). The changes in CIpw were unable to detect an increase in CItd >or= 15% induced by volume expansion and norepinephrine introduction/increase (area under ROC curves, 0.564 (0.398 to 0.720) and 0.541 (0.377 to 0.700, respectively, both not significantly different from versus 0.500).


CONCLUSIONS
The CIpc was reliable and accurate for assessing the CI changes induced by volume expansion and norepinephrine. By contrast, the CIpw poorly tracked the trends in CI induced by those therapeutic interventions.
Monnet
Xavier
X
AP-HP, Hôpital de Bicêtre, Service de Réanimation Médicale, 78 Rue du Général Leclerc, Le Kremlin-Bicêtre F-94270, France. xavier.monnet@bct.aphp.fr
Anguel
Nadia
N
Naudin
Brice
B
Jabot
Julien
J
Richard
Christian
C
Teboul
Jean-Louis
JL
D000368:Aged; D001158:Arteries; D001795:Blood Pressure Determination / Q000295:instrumentation*; D002302:Cardiac Output / Q000502:physiology*; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000008:administration & dosage / Q000494:pharmacology; D015203:Reproducibility of Results; D012772:Shock, Septic / Q000175:diagnosis / Q000503:physiopathology*; D013815:Thermodilution / Q000379:methods; D014662:Vasoconstrictor Agents / Q000008:administration & dosage / Q000494:pharmacology
D014662:Vasoconstrictor Agents; D009638:Norepinephrine