Nomograms and empirical equations relating oxygen tension, percentage saturation, and pH in maternal and fetal blood

Validity of nomograms relating the tensions of respiratory gases and pH in fetal blood

“…CO 2 -contents are not to be read at high C0 2 -tensions; there is always a positive Fig. 2 demonstrates the nomogram for the O 2 -dissociation curve of fetal blood published by HELLEGERS et al [3]. The percent saturation of hemoglobin was obtained from the nomogram using pH and pO 2 for entry.…”

“…The O 2 -content and CO 2 -content were obtained from the nomogram and compared with the measured values of the blood samples. HELLE-GERS et al nomogram [3] was entered with the mandatory factors of pH and pO 2 . Percent hemoglobin saturation was read and compared with the calculated value.…”

“…Thus 1782 values of the three nomograms were verified. The results of the nomograms of EDWARDS et al [1] and HELLEGERS et al [3] were compared with those of the nomogram of FISCHER et al [2] using the corresponding variables for entry. Γ f Fig.…”

“…Ilia and IHb). Percent saturation of hemoglobin was ascertained by entering the nomogram with pH and pO 2 as in the HELLEGERS et al [3] nomogram, and the results are presented in Tab. IIIc.…”

“…The nomogram constructed includes p0 2 and pC0 2 as well as 0 2 -and C0 2 -contents. HELLEGERS et al [3] provided a nomogram relating three variables in fetal blood: p0 2 , pH and percent saturation of hemoglobin. FISCHER et al [2] introduced the first nomogram depicting the interdependence of pO 2 , 0 2 -content, percent saturation of hemoglobin, pC0 2 , C0 2 -content and pH, thus enabling one to derive four variables if the other two are known.…”