Hypernatremia fluid intake

Eight years after stopping lithium because of polydipsia and polyuria, a 55-year-old woman was hospitalized with lethargy, coma, and hypernatremia (sodium concentration 156 mmol/1) after her fluid intake had been restricted (391). 

Hypernatremia Dehydration, net relative sodium excess Increase fluid intake, decrease sodium intake... 

Decreased intake of fluids—the elderly are at risk for hypernatremia owing to a decreased thirst mechanism that results in decreased fluid intake and dehydration. 

Hypernatremia and fluid retention commonly occur, necessitating restricting daily sodium intake to no more than 3 g. All sources of sodium, including antibiotics, need to be considered when calculating daily sodium intake. 

Hypernatremia results from loss of hypoosmotic fluid (e.g., in bums, fevers, high environmental temperature, exercise, kidney disease, diabetes insipidus) or increased Na+ intake (e.g., administration of hypertonic NaCl solutions, ingestion of NuHCOb). 

The goals in treating patients with hypernatremia include correction of the serum sodium concentration at a rate that restores and maintains cell volume as close to normal as possible, as well as normalizing the ECF volume in states of ECF volume depletion and expansion. Adequate treatment should result in the resolution of symptoms associated with hypovolemia. Careful titration of fluids and medications should minimize the adverse effects from too rapid correction. Modulation of dietary sodium intake and sodium replacement may be necessary to prevent recurrence of hypernatremia. 

Hypernatremia, that is, sodium levels of 146 mEq/L (146 mmol/L) or higher, results from excessive sodium intake or sodium retention with excessive loss of water owing to diarrhea, diurehc medicahon use, vomiting, sweating, heavy respirahon, or severe bums. Therefore, these pahents are at highest risk and should be monitored closely. Elderly hospitalized pahents should be watched most carefully because many have chronic diseases that may be fatal in combinahon with excessive sodium and fluid loss. 

The primary treatment for hyponatremia owing to excess free water in the body is to remove the excess water and, if indicated, to treat the source of water retention. If diuretics are used to remove water, the nurse must monitor intake and output and electrolytes closely. Most diuretics work by removing sodium and water thus sodium levels may remain low initially. If the patient is symptomatic, sodium supplement may be given. The nurse should monitor for signs of hypernatremia (e.g., thirst, agitation, and hyperreflexia), which indicates that too much fluid was removed or too much sodium was infused. Potassium loss may occur with diuretics as well, so the nurse should monitor for hypokalemia. 6... 

Use of diuretics and fluid restriction as treatment, and the nurse should monitor for excessive treatment and dehydration, including intake and output, weight loss, and hypernatremia, as stated earlier. 

Reduced absorption from the Gl tract has many causes, some of which are diarrhea, insufficient dietary intake, damage to the small intestine that may inhibit absorption, and malnutrition. Some common causes of excessive loss in the urine include diureses owing to alcohol, loop diuretics, and glycosuria. Other factors that may lead to hypomagnesemia are hypersecretion of aldosterone (causing hypernatremia), ADH, or thyroid hormone and excessive vitamin D (causing hypercalcemia) and intravenous fluids. 

The dehydration is aggravated by the lack of thirst response in the elderly, resulting in decreased intake of fluids and increased serum osmolality and hypernatremia. 

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