Clinical evaluation of renal function—use of chemical agents
RENAL function may be evaluated by a variety of clinical tests, some simple and some quite sophisticated. Some of the tests estimate the overall efficiency of the kidneys but may give few clues to specific diagnosis, while other tests may help to establish the diagnosis. Still others may be used to measure differentially the function of each kidney.
Most of the common renal diseases present a similar pattern of renal dysfunction and cannot be distinguished on the basis of simple clinical tests. Yet, the most precise tests for measuring various aspects of renal function are often too time consuming and cumbersome for general office or clinical practice. The ideal renal function test should be safe, accurate, simple to perform, require no laboratory facilities, and should be specific in that the results are affected only by changes in renal function. The tests discussed in this paper do not meet those ideal specifications, yet, when used singly or in combination these tests provide valuable information in regard to the overall adequacy of renal function.
Urinalysis provides critical information about the presence or absence of renal disease and should always be performed by the physician responsible for the patient. A properly collected midstream specimen of urine is most suitable for examination since it avoids contamination by prostatic or vaginal secretions and the risk of causing ascending infection induced by catheterization. The introduction of simple yet sensitive chemical methods for the detection of protein, glucose, and bacteria has made urinalysis a reliable indicator of . . .