Functional Types of Acute Renal Failure and Their Early Diagnosis

Since it is important diagnostically and therapeutically to recognize the factors responsible for a given case of acute renal failure, a classification of the various functional types of acute uremia should prove of clinical usefulness. The designation extrarenal azotemia does not appear to serve a very useful purpose in this regard, since such a term does not appropriately indicate the insufficient renal function which is usually present in the so-called extrarenal azotemias. Even the term extrarenal uremia is ambiguous and conducive of confusion for the obstructive or postrenal uremias have not been classified as extrarenal uremias,1,2as they should be semantically. The purpose of this paper is to suggest a clinically useful functional classification for the acute uremias, to review briefly the chief functional types of acute renal failure while relating pathophysiologic processes in the kidney to a few important urinary signs, and to point out practical aids with