SENSITIVITY OF RESIDUAL NEPHRONS TO HIGH-DOSE FUROSEMIDE DESCRIBED BYDIURETIC EFFICIENCY

Ten haemodialysis (HD) patients with a median residual creatinine clea rance (CL(CR)) of 1.9 ml . min(-1) . 1.73 m(-2) (range 0.6-5.3) were t reated with oral furosemide (F) 2.0 g. Overall-efficiency (O-E, daily sodium excretion/total urinary F) and total-efficiency (Delta-E, incre ase in daily sodium excretion/total urinary Fl were measured on the la st 24 hours of each interdialysis interval. In addition, O-E was measu red during the complete interdialysis interval in 10 HD patients with a median CL(CR) of 5.6 ml . min(-1) . 1.73 m(-2) (range 0.7-6.5) treat ed for 1 year with a fixed oral dose of F between 250-1000 mg (median 625 mg). In the short study the median O-E was 10.6 mmol . mg(-1) (ran ge 1.9-22.0) and Delta-E 6.2 mmol . mg(-1) (range 1.3-11.2). The fract ional. excretion of sodium FE(Na) was significantly increased from 9.6 % (range 4.1-22.9) to 27 % (range 14.6-56.2) during F treatment. A po sitive correlation was found between the basal FE(Na) and Delta-E. In the long-term study median O-E was 6.4 mmol . mg(-1). O-E and FE(Na) s howed no change over time although median RCC decreased from 5.6 to 1. 9 ml . min(-1) 1.73 (m-2) and median F excretion from 11.8 to 7.5 mg p er day. It can be concluded that diuretic efficiency in haemodialysis patients is dependent on FE(Na) and the state of hydration during the interdialysis interval.