Calculate total fluid and electrolyte needs according to the maintenance and deficit replacement formulas in sections B to D above. NS is used. Potassium can be added after urine output is established. Give half of the calculated total fluid and electrolyte requirements for the first 24 hours over the first 8 hours and the other half over the next 16 hours. Severe, symptomatic hyponatremia.
Symptoms are less dramatic than in hypotonic dehydration.
Remember to estimate and replace ongoing losses. Usually occurs as a result of using inappropriately high solute load as replacement, renal concentrating defect with large free-water losses, heat exposure with large insensible losses, etc. Shock is a very late manifestation. Replace the free-water deficit slowly over 48 hours. Reducing serum sodium more rapidly can have severe repercussions, such as cerebral and pulmonary edema.