Hypernatremia Clinical Presentation

Updated: Jan 04, 2021
  • Author: Ivo Lukitsch, MD; Chief Editor: Vecihi Batuman, MD, FASN  more...
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Presentation

History

Patients developing hypernatremia outside of the hospital setting are generally elderly and debilitated, and often present with an intercurrent acute (febrile) illness. Hospital-acquired hypernatremia affects patients of all ages.

The history should be used to discover why the patient was unable to prevent hypernatremia with adequate oral fluid intake. For example, the clinician should determine whether the patient is suffering from an altered mental status or whether there are any factors causing increased fluid excretion (eg, diuretic therapy; diabetes mellitus; or fever, diarrhea, and vomiting). The history should also cover the symptoms and causes of possible diabetes insipidus (eg, the presence of preexisting polydipsia or polyuria, a history of cerebral pathology, or medication use [lithium]).

It is important to find out if the hypernatremia developed acutely or over time, because this will guide treatment decisions.

Risk factors for hypernatremia include the following:

  • Advanced age
  • Mental or physical impairment
  • Uncontrolled diabetes (solute diuresis)
  • Underlying polyuria disorders
  • Diuretic therapy
  • Residency in nursing home, inadequate nursing care
  • Hospitalization [22, 32]

Hospitalized patients may develop hypernatremia because of any of the following:

  • Decreased baseline levels of consciousness
  • Tube feeding
  • Hypertonic infusions
  • Osmotic diuresis
  • Lactulose
  • Mechanical ventilation
  • Medication (eg, diuretics, sedatives)
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Physical Examination

The examination should include an accurate assessment of volume status and cognitive function. Symptoms can be related to volume deficit and/or hypertonicity and shrinkage of brain cells, which can tear cerebral blood vessels in severe cases, leading to cerebral hemorrhage.

The worsening symptoms associated with hypernatremia may go unnoticed in elderly patients who have a preexisting impairment of their mental status and decreased access to water.

Table 1. Characteristics and symptoms of hypernatremia (Open Table in a new window)

Characteristics of hypernatremia

Symptoms related to the characteristics of hypernatremia

Cognitive dysfunction and symptoms associated with neuronal cell shrinkage

Lethargy, obtundation, confusion, abnormal speech, irritability, seizures, nystagmus, myoclonic jerks

Dehydration or clinical signs of volume depletion

Orthostatic blood pressure changes, tachycardia, oliguria, dry oral mucosa, abnormal skin turgor, dry axillae,

Other clinical findings

Weight loss, generalized weakness

In a prospective, case-control, multicenter study, Chassagne and colleagues looked at the symptoms associated with hypernatremia in 150 geriatric patients. [33]  The likelihood that patients with hypernatremia would have low blood pressure, tachycardia, dry oral mucosa, abnormal skin turgor, and a recent change in consciousness was significantly greater than that of the controls. The only clinical findings to occur in at least 60% of patients with hypernatremia were orthostatic blood pressure and abnormal subclavicular and forearm skin turgor (poor specificity and sensitivity for all physical findings).

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