Al. Nielsen et al., OXYGEN AND 2,3-BIPHOSPHOGLYCERATE (2,3-BPG) DURING HEMODIALYSIS, Scandinavian journal of clinical & laboratory investigation, 58(6), 1998, pp. 459-467
Eleven patients with chronic renal failure who were being treated with
haemodialysis three times a week were monitored for a total of 34 hae
modialysis sessions. Erythrocyte 2,3-biphosphoglycerate (2,3-BPG) conc
entration was analysed immediately before initiation of bicarbonate ha
emodialysis and 1 h afterwards. The 2,3-BPG concentration was expresse
d relative to the haemoglobin tetramer (Hb(4)) concentration as the 2,
3-BPG/Hb(4) ratio and compared with blood gas analyses and biochemical
variables important for characterizing uraemia. During the first hour
bf haemodialysis the 2,3-BPG/Hb(4) ratio decreased (p < 0.002), but t
he magnitude of the decrease did not significantly correlate with the
2,3-BPG/Hb(4) ratio measured before haemodialysis (p = 0.104). The dec
rease is most likely to be caused by the haemodialysis procedure itsel
f. Mechanical stress on the erythrocytes is believed to cause the 2,3-
BPG to escape; it is then removed by haemodialysis. Physiologically, a
n increase in 2,3-BPG would be expected to counteract the hypoxia whic
h is frequently observed during haemodialysis. However, the present re
sults show the opposite, a decrease in 2,3-BPG. No significant correla
tion was shown between the haemoglobin concentration and the 2,3-BPG/H
b(4) ratio before dialysis (p = 0.414). The pH showed a significant po
sitive correlation with the 2,3-BPG/Hb(4) ratio before dialysis, where
as the arterial pO(2) and the 2,3-BPG/Hb(4) ratio before dialysis were
insignificantly negatively correlated. The concentrations of calcium,
phosphate, creatinine, urea and-albumin did not correlate significant
ly with the change in 2,3-BPG/Hb(4)-ratio after 1 h. The 2,3-BPG/Hb(4)
ratio (p = 0.03) sampled just before dialysis correlated significantl
y and positively with the total weekly dosage of erythropoietin given
to the patients.