Mechanism of diet-induced uraemia and acidosis in infants.

Five patients aged between 40 and 70 days were admitted to our Clinic with an initial diagnosis of "renal failure", but the high levels of urea nitrogen, metabolic acidosis and oliguria were found to be related to a high renal solute load and to the very high protein and electrolyte content of the diet. By calculating urinary output (V/m'), clearance of osmotically-active substances (COsm), clearance of free water (CH2O), maximum tubular reabsorption of water (TcH2O) and the change in metabolic H+ production, it has been possible to demonstrate that dietary protein and electrolytes were both responsible for the high blood urea nitrogen levels and metabolic acidosis.