Definition – Na > 145 mmol/L

Treatment precautions – Aggressive treatment of hypernatremia is not indicated as it can cause cerebral edema. Reduction of the sodium levels should be done cautiously. Sodium levels should drop no faster than 1-2 mEq/hr until the patient is within the normal sodium levels and exhibiting clinical stability.

Sodium replacement – Be mindful if the cause is sodium replacement. Slow onset hypernatremia allows the brain to adapt by conserving intracellular solutes, whereas rapidly occurring hypernatremia can cause rapid shrinkage of brain tissues. This rapid shrinkage creates traction on cerebral vessels which can lead to hemorrhage.

Most often the result of impaired water intake – This makes the mentally impaired, debilitated, and long-term intubated patients at particular risk. Since there is a shortage of diluting water in the bloodstream, there will be other indicators of a hyper-concentrated blood. This will exhibit as an increased hematocrit, increased serum protein levels, low urine output, elevated BUN and creatinine.

Signs and Symptoms – Stupor, coma, seizures, hypovolemia, renal insufficiency, decreased urinary concentrating ability

Risks – Impaired water intake (most common), impaired ADH secretion, hypertonic IV solution administration, bicarbonate administration, diabetes insipidus, neurosurgery patients (pituitary disruption that leads to transient diabetes insipidus), Geriatric patients (due to decreased urine concentrating ability and decreased thirst)