CHANGES OF ARTERIOVENOUS DIFFERENCES IN PH AND PCO(2) BY HEMODIALYSIS

Normally the differences in arterial-venous pH (A-VpH) and veno-arteri al pCO(2) (V-ApCO(2)) are small and constant. This study deals with A- VpH and V-ApCO(2) and their effect on arterial-venous saturation hemog lobin percentage (A-VSHb%) in uremic patients under hemodialysis (HD). In 17 uremic patients under HD with acetate, blood samples were colle cted anaerobically in heparinized syringes from artery (fistula) and v ein (forearm without fistula) pre- and post-HD. In these samples pH, p CO(2) and SHb% were determined and A-VpH, V-ApCO(2) and A-VSHb% were e stimated. Comparison between the values pre-and post-HD of A-VpH, V-Ap CO(2) and A-VSHb% shows that these three values were decreased signifi cantly post-HD (p<0.001). The correlation of all values (pre- and post -HD) of A-VpH and V-ApCO(2) with that of A-VSHb% was significant and p ositive (r=O.514 p<0.01, r=O.505 p<0.01, respectively).