The influence of changes in pCO2 on the fractional packed cell volume of whole blood.

In order to investigate the influence of changes in pCO2 on the fractional packed cell volume (FPCV, hematocrit) of whole blood, a device for measuring the conductivity was developed. This method allows an instantaneous and continuous determination of the FPCV, because the erythrocyte membrane has insulating properties, and, consequently, the resistance of blood depends on the relative cell volume. The steady state and transient relationships between FPCV and acid-base levels were investigated by combining this method with simultaneous recordings of pCO2.