[Metabolic acidosis in chronic renal insufficiency of various etiology].

The renal acidosis may appear by a decrease of the number of nephrons able to function (decrease of the filtrate of the glomerulum) as well as by a selective alteration of the tubular acidification mechanism. In 66 patients with chronic renal insufficiency of different degrees of severity (32 patients with diabetic glomerulosclerosis, 18 patients with chronic glomerulonephritis and 16 patients with chronic pyelonephritis) studies of the parameters of the acid-base-state and the renal insufficiency were carried out. 53 of these patients had a pathologically changed acid-base-state which was most expressed in patients with chronic pyelonephritis. A characteristic relation between the renal function (creatinine clearance) and the change of the pH-values was observed. The regression curve of the pH-values was descending so that in clearance values below 25 ml/min in nearly all patients a pronounced acidosis was present. This could be proved in the patients with pyelonephritis already when higher clearance values were present. The forms of the development of the metabolic acidosis in chronic renal insufficiency are discussed.