[Investigations into urea elimination in patients with advanced chronic renal failure during forced diuresis].

Controlled balance studies were performed in 12 oedema-free patients with advanced chronic renal failure with optimal dietary pretreatment. Forced water diuresis did not result in a significantly increased urea excretion as compared with spontaneous diuresis. Furosemide diuresis resulted in a significant increase (P less than 0.05) which was irrelevant therapeutically. The serum urea may even increase slightly under furosemide due to massive fluid loss. During thirst-regulated diuresis of advanced chronic renal failure urea back-diffusion is probably already reduced to a minimum. Normal hydration provided, forced water diuresis (oral or parenteral fluid) is useless and irresponsible as it poses additional risks in such patients. Furosemide in high dosage in over-hydrated patients is an effective diuretic even in advanced renal failure. The slightly significant increase in urea excretion during furosemide treatment does not result in important benefits in dietetically well treated patients.