| Abstrakt: |
TO THE EDITOR:— Phenolsulfonphthalein (PSP) excretion tests were discussed in The Journal (195: 1078, 1966). I recently reevaluated this subject (Arch Int Med117:74, 1966).The amount of dye excreted by the kidney in the first 15 minutes after its intravenous administration is a good index of renal tubular function. However, the voided specimen at 15 minutes may not reflect the renal function. Decreased dye in that specimen can be due to incomplete bladder emptying or a slow rate of urine formation. Incomplete bladder emptying can be detected by finding decreased dye excretion in the first 15-minute specimen and normal excretion in one or two hours. (PSP, not promptly excreted by the kidneys, [1] is excreted by the liver and [2] diffuses out of the plasma. With the falling plasma level, progressively less dye is available for renal excretion.) The reason for having the patient empty his bladder before |
