Indirect calorimetry can be used to measure cardiac output in septic patients?
OBJECTIVE
The aim of this study was to compare two different cardiac output (CO) monitoring systems based on the thermodilution principle (Thermo-CO) and indirect calorimetry (Fick mixed-CO) in septic patients.


METHODS
Prospective study in septic patients admitted in an intensive care unit of a university hospital. Nineteen patients aged on average 45.4 +/- 21.5 years were enrolled in the study. Four series of hourly measurements by the two techniques were carried out simultaneously.


RESULTS
No significant differences were observed between Thermo-CO and Fick mixed-CO (7.0 +/- 1.8 L.min-1 and 6.4 +/- 1.7 L.min-1.). Parallel analysis of Fick mixed-CO and Fick atrial-CO was performed introducing a correction factor for the eight atrial samples in order to adjust the values of oxygen saturation obtained from atrial blood (Fick corrected atrial-CO) to those obtained from mixed venous blood. No significant differences could be detected between Fick mixed-CO and Fick corrected atrial-CO. The correlation coefficients of Thermo CO/Fick mixed-CO and Fick mixed-CO/Fick corrected atrial-CO were 0.84 and 0.94, respectively.


CONCLUSIONS
We observed that the agreement between the two methods was satisfactory on the basis of the decisions made for treatment. Indirect calorimetry is useful to measure CO in patients with septic shock.
Division of Intensive Care Unit, Department of Surgery and Anatomy, Ribeirão Preto Faculty of Medicine, University of São Paulo, SP, Brazil.
Maria
M
Auxiliadora Martins
Francisco Antônio
FA
Coletto
Antônio Dorival
AD
Campos
Anibal
A
Basile-Filho
D018806:APACHE; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002153:Calorimetry, Indirect / Q000592:standards*; D002302:Cardiac Output / Q000502:physiology*; D003422:Critical Care; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D011014:Pneumonia / Q000503:physiopathology* / Q000628:therapy; D011446:Prospective Studies; D012772:Shock, Septic / Q000503:physiopathology* / Q000628:therapy; D013815:Thermodilution / Q000592:standards*; D016896:Treatment Outcome; D055815:Young Adult