Читать книгу Disorders of Fluid and Electrolyte Metabolism - Группа авторов - Страница 35

As noted above, normal dietary consumption varies between 600 and 900 mOsm of solute per day. The main solutes are urea (from the metabolism of proteins generating approximately 50 mmol of urea per 10 g of protein intake) and electrolytes (Na, K, and accompanying anions). Carbohydrates do not contribute to the solute load. In steady state conditions, solute intake is equal to urine solute load. From equation 4, one can infer that the urine volume, and hence water excretion, is dependent on the urine solute load [22]. If a patient consumes only 100 mOsm of solute per day, the daily urine solute excretion will also be 100 mOsm. Assuming the urine is maximally diluted (UOsm of 50 mOsm), the daily solute load will generate only 2 L of urine (i.e., 100/50 in equation 4) and an intake of fluids merely exceeding this amount will culminate in the development of hyponatremia.