EFFECT OF REGIONAL CIRCULATION PATTERNS ON OBSERVED HBCO LEVELS

In an earlier experiment, we briefly exposed 15 young men to high leve ls of CO while simultaneously monitoring arterial and peripheral venou s HbCO levels. The arterial HbCO levels were considerably higher than the venous levels during the CO exposure. Furthermore, great variation in the difference between arterial and venous HbCO levels was observe d, with the maximal difference for each subject ranging from 2.3 to 12 .1% HbCO. In the present paper, we suggest an explanation for the obse rved differences between arterial and venous HbCO on the basis of the regional circulation of the forearm, where both samples were taken. Be cause regional circulation patterns are known to vary with physical tr aining, the differences in physical training between subjects may acco unt for the observed variation. An expanded model was derived from the Coburn-Forster-Kane equation, which reflects the above hypothesis. Mo st of the parameter values for the expanded model were measured on ind ividual subjects. Literature values were used for other parameters. Tw o parameters were estimated using five of the subjects and were then u sed in the predictions of the expanded model for the remaining subject s.