Hemoglobin oxygen affinity in patients suffering from arterial occlusive disease of the legs

Abstract

Parameters characterizing the hemoglobin oxygen affinity were determined in blood of 12 male patients suffering from arterial occlusive disease (AOD) of the legs and compared with data obtained earlier from healthy human subjects (controls). Due to a COHb content of 4.8% +/- 2.2% in the cigarette-smoking AOD patients, the standard oxygen dissociation curve (ODC) was left-shifted, the half-saturation pressure (P50) amounted to 24.8 +/- 1.7 mmHg (3.30 +/- 0.23 kPa), although the 2,3-diphosphoglycerate concentration was increased to 15.3 +/- 1.7 mumol/g Hb. Correcting the effects of elevated COHb shifts the P50 to 26.3 mmHg (3.5 kPa) and increases the steepness of the ODC (Hill's "n") from 2.79 +/- 0.27 to about 2.99, which is significantly different from controls. The Bohr coefficients after acidification of blood with lactic acid (BCLac) show high values at low oxygen saturations of hemoglobin (-0.50 +/- 0.04 in AOD patients, -0.32 +/- 0.04 in controls; P less than 0.05 at 10% SO2). The cause of the alterations in hemoglobin oxygen affinity may be a reduced mean erythrocyte age, but also the influence of unknown factors generated, e.g., from anaerobic muscle metabolism in AOD.

The oxygen dissociation curve of blood in COVID-19–An update

“…Since right shifts of the ODC in venous blood have been observed during exercise, e.g., (20,53,54) as well as in disease (21,55), this is not entirely surprising. Such a right shift facilitates oxygen delivery to consuming tissues, yet it simultaneously impacts oxygen uptake in the lungs.…”

“…The slope n is rather constant over a large range of SO 2 [e.g., (19)] allowing to calculate a standard P 50 from one pair of PO 2 and SO 2 measurements. However, n may be influenced by additional factors such as physical training (20) or illness, e.g., peripheral artery disease (21) or cystic fibrosis (19).…”

“…This finding is reminiscent of the results of Vogel et al (30), where the P 50 values calculated for low SO 2 tended to lie to the right of the standard curve. Similarly, measurements in venous blood during physical exercise often show a deviation to the right [e.g., (21,63,64)]. The causes for this right-shift are not fully explained.…”