[Dialysis quantity and dietary protein during continuous ambulatory peritoneal dialysis]

Calculation of a dialysis index (Teehan; Perit Dial Bull 1985, 3:152-156) and estimations of the protein catabolic rate (PCR) (reflecting protein intake under steady state conditions) were performed in 20 CAPD patients instructed to eat 1.2-1.5 g/kg BW protein per day and treated with 8-101 dialysate exchange per day. Dialysis indices were 1.20 +/- 0.44, greater than 1.0 reflecting adequate treatment. PCR was based on nitrogen loss by dialysis and urine as well as by losses assumed to be constant in stools and through skin; dialysis loss was obtained either by collection of the 24 h dialysate volume or by estimating the equilibration ratio between blood and dialysate for calculation of nitrogen removal from serum urea nitrogen and 24 h dialysate volume. Values obtained were 0.90 +/- 0.23 and 0.89 +/- 0.23 g/kg BW, respectively (r = 0.97, P = 0.0001). These low PCR values were found to correlate with data from dietary surveys (r = 0.77). Total serum protein, albumin content and transferrin concentration were all within the normal range and there was no correlation between these parameters and protein intake. It is concluded that protein intake and dialysis adequacy must be monitored individually. Whereas generally recommended CAPD schedules provide effective treatment, a mean protein intake greater than 0.9 g/kg BW seems to be adequate.