G. Cieslinski et al., COMPARISON OF CALCULATED AND MEASURED MIXED VENOUS OXYGEN-SATURATION IN CRITICALLY ILL PATIENTS, Infusionstherapie und Transfusionsmedizin, 22(6), 1995, pp. 340-343
Objective: According to the Fick principle the calculation of cardiac
output and shunts is based on the exact determination of oxygen satura
tion, In this study an intraindividual comparison of two frequently ap
plied methods was done. Design and Setting: The calculated saturation
by measuring partial oxygen pressure was compared with a gold standard
, the reflectometrically measured saturation. Patients: 75 patients of
an intensive care unit in whom a Swan-Ganz(R) catheter was introduced
to answer clinical questions. Results: Overall, most calculated value
s were higher than the measured ones, the mean difference was 5.9% (+/
- 8.03%), ranging from -10.4 to +37%. In lower saturations (<65%) the
difference between both estimated values was larger than in the range
above 65%. Conclusions: Especially when handling with lower oxygen sat
urations, calculation of saturation with an automatic pas analyzer lea
ds to overestimated values. The Fick principle can only be applied for
hemodynamic calculations when oxygen saturation can be determined by
an easy and correct method.