Post-obstructive diuresis.

Massive diuresis after relief of urinary tract obstruction has been divided into 3 categories: 1) salt, 2) urea and 3) water. Measurements of the urinary electrolytes and urine osmolality establish the character of the diuresis and facilitate in the fluid management of these patients. A clinical example of the 2 most common varieties, salt and urea, is presented in conjuction with the method of fluid replacement.