Mh. Mokrzycki et Aa. Kaplan, PROTEIN LOSSES IN CONTINUOUS RENAL REPLACEMENT THERAPIES, Journal of the American Society of Nephrology, 7(10), 1996, pp. 2259-2263
Continuous renal replacement therapy (CRRT) has become a popular treat
ment modality but may have the disadvantage of producing substantial p
rotein losses. With use of the Biuret method, a relatively insensitive
assay, dialysate/ultrafiltrate protein losses have been reported to b
e as high as 1.3 g/L. With CRRT outputs of up to 50 L/day, these value
s would amount to protein losses of up to 65 g/day. In this study, dia
lysate/ultrafiltrate protein losses were reanalyzed by using a highly
sensitive microprotein reagent (pyrogallol red) considered to be more
accurate than previously available methods. Twenty-two dialysate/ultra
filtrate samples were obtained from Amicon-20 Diafilters or Fresenius
F-80 dialyzers during continuous venovenous hemofiltration (CVVH) or c
ontinuous venovenous hemodialysis/hemodiafiltration (CVVHD/F). Mean ho
urly output for all treatments was 1637 +/- 694 mL/h. Mean protein con
centration for all 22 dialysate/ultrafiltrate samples was 4.2 +/- 4.0
mg/dL, Mean dialysate/ultrafiltrate protein concentrations were simila
r for the Amicon 20 (3.4 +/- 4.4 mg/dL, N = 9) and the Fresenius F-80
(4.7 +/- 3.9 mg/dL, N = 13) (P = not significant). Protein losses were
higher during convection-based CVVH (6.0 +/- 5.1 mg/dL, N = 10; range
, 1 to 15 mg/dL) than during the mixed convection and diffusion-based
CVVHD/F (2.7 +/- 1.9 mg/dL, N = 12; range, 0 to 6 mg/dL) (P = 0.049).
Mean serum protein concentration at the time of dialysate/ultrafiltrat
e sampling was 4.7 +/- 1.8 g/dL. There was a weak, but statistically s
ignificant correlation between the dialysate/ultrafiltrate samples and
the corresponding value for serum protein (r = 0.468, P < 0.03). It w
as concluded that protein losses during CRRT treatments are substantia
lly lower than previously reported, are dependent on the serum protein
concentration and the predominant nature of solute removal (convectio
n versus diffusion), and can vary between 1.2 and 7.5 g/day.