Interrelationships between blood pressure, blood gases and plasma acetate concentrations during conventional...

To determine to what extent the intradialysis changes in blood pressure (BP) are related to the variations in blood gases and plasma acetate concentrations (plAc), 11 dialysed uremics were studied with measurement of plAc,pH, pCO2 and pO2 every 60' during a hemodialysis lasting 4 hrs. Dialysis resulted in significant decreases in the BP, pO2 and pCO2 and in significant increases in pH and plAc. Multiple regression analysis demonstrated that the delta % for the mean BP was closely related to plAc, pCO2 and delta-% of body weight (BW). Partial regression coefficient indicated the following rank order of correlation: plAc greater than pCO2 greater than or equal to delta-% BW greater than pO2 = O, thus demonstrating that the fall in blood pressure is related both to the increase in plAc and the decrease in pCO2. The physiological relevance of these relationships is discussed. The hypothesis is advanced that the pCO2 decrease during dialysis might contribute to the acetate-induced vascular instability.