Prognosis

The short-term mortality rate in patients with hypernatremia has been reported to be 32% to 70%.[10][12]​​​​[17][20][41][47]​​​​​​ Patients with hypernatremia tend to do worse than patients with other electrolyte abnormalities such as hyponatremia.[15][104][105]​​​ Studies have shown that older adults in hospital who have hypernatremia have higher mortality rates.[71]​ Disorders of sodium balance (whether hospital- or community-acquired) are independent risk factors for in-hospital mortality.​[1][10][106][107]

Severity of hypernatremia

The relative contribution that hypernatremia makes to a poor prognosis in patients with serious underlying diseases is unclear. Some authors believe that, at least with severe hypernatremia, the hypernatremia itself contributes to a poor prognosis.[108] One study found that hypernatremia directly contributed to mortality in 16% of patients.[12]​ Another study found that only severe hypernatremia (defined as >160 mEq/L in the study) was independently associated with mortality in a neurologic intensive care unit.[109] Hypernatremia has also been shown to be an independent risk factor for mortality in other intensive care units.[18][110][111] Interestingly, it is the severity of the hypernatremia, not the duration, that was associated with mortality, especially with community-acquired hypernatremia.[20][112]

Chronic, mild hypernatremia and normal serum sodium concentrations that are at the higher end of the normal range have been associated with a significantly increased risk of cardiovascular events and mortality in older men.[113] Preoperative hypernatremia has also been found to be an independent predictor of perioperative morbidity and mortality.[114][115] Hypernatremia has been associated with longer hospital stays.[116]

Recurrence

Recurrence depends on whether the inciting factors continue to be present. In patients with dementia who do not have access to water or who have lost their sense of thirst, the risk of developing hypernatremia is always high.

Use of this content is subject to our disclaimer