"Computational" blood oxygen status: requirements and limitations.

The influences of analytical variation of sO2 and pO2 measurements on the oxygen parameters p50, pO2uv-, DavO2c, CQ are examined by simulation. The greatest deviations occur when pO2 and sO2 are changing in opposite directions. p50 and pO2uv- are least sensitive against analytical variations. Differences between p50 results from arterial and mixed venous blood are discussed. The calculation of the new oxygen parameters should be restricted to blood samples with sO2 not higher than 0.96. The need for an oxygen parameter expressing the combined effects of oxygenation, Hb concentration and oxygen affinity is emphasized.