HIGH BICARBONATE DIALYSATE IN HEMODIALYSIS-PATIENTS - EFFECTS ON ACIDOSIS AND NUTRITIONAL-STATUS

Background. Metabolic acidosis adversely affects both protein and bone metabolism in patients with chronic renal failure, and could also aff ect morbidity and mortality. This trial aimed to investigate the effec ts of different dialysate bicarbonate concentrations on control of aci d base balance, and nutritional status. Methods. Forty-six stable haem odialysis patients were dialysed using LowBic. (30 mmol/l) or HighBic. (40 mmol/l) bicarbonate dialysate in a single blind double crossover trial, of two consecutive six-month periods. Blood gas analysis, anthr opometric indices and dialysis dose were measured, in addition to bioc hemical indices. Results. Predialysis 'arterial' plasma pH values were significantly higher when using the HighBic. dialysate (LowBic. 7.38/-0.05, HighBic. 7.43+/-0.04, P < 0.001), as was predialysis serum tot al CO2 at all times during the study (P < 0.01). Kt/V, (LowBic. 1.27+/ -0.19, HighBic. 1.27+/-0.25), urea generation rates (UGR) (LowBic. 1.9 9+/-0.77, HighBic. 1.92+/-0.77 mmol/min), and normalized protein catab olic rate (NPCR) (LowBic. 1.04+/-0.26, HighBic. 0.99+/-0.28 g/kg/day) did not differ, and values of parathroid hormone (PTH) were comparable . Triceps skinfold thickness (TSF) showed a significant change (LowBic . 14.8+/-6.9-11.8+/-5.5, HighBic. 14.9+/-6.3-15.8+/-6.4 mm, P < 0.05) which was reversed following dialysate change (HighBic. 11.8+/-5.5-13. 3+/-7.2, LowBic. 15.8+/-6.4-13.8+/-6.7 mm, P < 0.05). No differences i n mid upper arm circumference were found. Conclusions. Bicarbonate dia lysate concentrations of 40 mmol/l were safe, well tolerated, and prod uced better control of acidosis, with an increase in TSF, compared to a bicarbonate concentration of 30 mmol/l.