How often do you check urine osmolality and urine electrolytes when treating hospitalized patients with hyponatremia?  

Correction of hypovolemia with isotonic saline may result in overly rapid correction of hypovolemic hyponatremia once the stimulus for ADH secretion is removed, resulting in the excretion of a very dilute urine. Therefore, urinary electrolytes and osmolality should be closely monitored every 3-4 hou...

I check every 3-4 hours for UOSM and UNa. Urine volume should be checked by staff every 2 hours, as that will provide the earliest indication of impending rapid correction.