Format

Send to

Choose Destination
J Thorac Cardiovasc Surg. 2005 Aug;130(2):272-6.

Assumed oxygen consumption frequently results in large errors in the determination of cardiac output.

Author information

1
Department of Pediatric Cardiology and Congenital Heart Disease, Technische Universität München, Germany. fakler@dhm.mhn.de

Abstract

OBJECTIVE:

We sought to investigate the differences in assumed and measured oxygen consumption values for the determination of cardiac output by using the Fick principle in a pediatric population with congenital heart disease.

METHODS:

The patient population consisted of 143 patients with a mean age of 11.3 years (age range, 2 days to 23.8 years) undergoing cardiac catheterization during general anesthesia and with mechanical ventilation. Oxygen consumption was measured with a standard commercial analyzing system (Deltatrac II; Datex, Engström, Helsinki, Finland). Assumed oxygen consumption values were calculated according to the formulas of Krovetz and Goldbloom and LaFarge and Miettinen. Comparisons between measurements and assumptions were performed by Bland-Altman plots. Two-sided paired t tests were used to assess a difference of the assumed and measured values.

RESULTS:

The range of measured oxygen consumption values was between 55.2 and 249 mL . min -1 . m -2 . The Krovetz-Goldbloom formula led to systematically larger values compared with the measured values (P = .0001; mean difference of -53.3 mL . min -1 . m -2 ; 95% confidence interval, -56.7 to -49.8 mL . min -1 . m -2 ). The use of the LaFarge-Miettinen formula tends to overestimate oxygen consumption (P = .0037; mean difference of -15.9 mL . min -1 . m -2 ; 95% confidence interval, -26.5 to -5.4 mL . min -1 . m -2 ). A similarly poor agreement was found when analyzing a subgroup of 25 patients with Fontan-type circulation.

CONCLUSION:

The use of assumed instead of measured oxygen consumption values introduces large errors in the determination of cardiac output.

PMID:
16077386
DOI:
10.1016/j.jtcvs.2005.02.048
[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center