The acid-base status does not influence the rate of acetate metabolism in hemodialyzed patients

The present study was undertaken to evaluate whether the acid-base status influences the rate of acetate metabolism in patients chronically hemodialyzed against acetate. Ten patients (5 "intolerant" and 5 "tolerant" to acetate) received in a randomized order and for three consecutive dialyses each of the six following infusions in the venous line of the dialyzer: NaHCO3 (22, 44 or 88 mEq/h), NaCl (22 or 44 mEq/h) or Dextrose 5% in water (30 mmol/h). Plasma acetate was measured at the end of the dialysis. Bicarbonate infusions increased significantly blood pH and plasma bicarbonate but did not change the plasma acetate concentration at the end of dialysis. We conclude that the rate of acetate metabolism is not modified by changes in the acid-base status within the range usually observed in hemodialyzed patients. A significant hypoxemia per dialysis was noted only in AT patients with lower plasma acetate and rapid acetate metabolism. We conclude that acetate metabolism (and not plasma acetate concentration) plays a significant role in dialysis-induced hypoxemia.