Abstract
In order to evaluate the optimal concentration of dialysate bicarbonate, we studied the blood-gas data and correlation between dialysate bicarbonate and post-dialysis plasma bicarbonate in a total of 118 dialyses in 31 stable chronic hemodialysis patients. The dialysate was Kindary AF-1, which contained about 8mEq/l of acetate. We changed dialysate bicarbonate levels from 20.5mEq/l to 35.2mEq/l for every dialysis. Hemodialysis was done for four hours, with a blood flow of 150ml/min and a dialysate flow of 500ml/min, using a hollow fiber dialyzer with a surface area of 0.8m2 to 1.2m2.
It was desirable to increase plasma bicarbonate to about 24mEq/l at the end of dialysis.
One hundred ten dialysis sessions were divided into three groups depending on predialysis plasma bicarbonate levels: the mild acidosis group (20≤HCO3-<24mEq/l, n=31), the moderate acidosis group (16≤HCO3-<20mEq/l, n=60), and the severe acidosis group (HCO3-<16mEq/l, n=19). In all three groups, there was a high positive correlation between dialysate bicarbonate and post-dialysis plasma bicarbonate. The optimal concentration of dialysate bicarbonate was suggested as to be 23.8mEq/l for the mild acidosis group, 27.9mEq/l for the moderate acidosis group and 30.0mEq/l for the severe acidosis group.
In conclusion, the optimal concentration of dialysate bicarbonate was variable depending on the predialysis plasma bicarbonate level. In the mild acidosis group, bicarbonate dialysis may cause alkalosis after dialysis. It is desirable to use two or more bicarbonate dialysates properly with different concentrations.
