Interrelationships between Blood Pressure,Blood Gases and Plasma Acetate Concentrations during Conventional Hemodialysis

Abstract

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 Δ% for the mean BP was closely related to plAc, pCO₂ and Δ⁻ % of body weight (BW). Partial regression coefficient indicated the following rank order of correlation: plAc > pCO₂ ≥ Δ⁻% BW > 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.