Hypernatremia
Hypernatremia | |
---|---|
Other names | Hypernatraemia |
Types | Low volume, normal volume, high volume[1] |
Diagnostic method | Serum sodium > 145 mmol/L[3] |
Differential diagnosis | Low blood protein levels[4] |
Frequency | ~0.5% in hospital[2] |
Hypernatremia, also spelled hypernatraemia, is a high concentration of
Hypernatremia is typically classified by a person's fluid status into
If the onset of hypernatremia was over a few hours, then it can be corrected relatively quickly using
Signs and symptoms
The major symptom is thirst.[8][9] The most important signs result from brain cell shrinkage and include confusion, muscle twitching or spasms. With severe elevations, seizures and comas may occur.[8]
Severe symptoms are usually due to acute elevation of the plasma sodium concentration to above 157 mmol/L[10] (normal blood levels are generally about 135–145 mmol/L for adults and elderly).[10] Values above 180 mmol/L are associated with a high mortality rate, particularly in adults.[11] However, such high levels of sodium rarely occur without severe coexisting medical conditions.[12] Serum sodium concentrations have ranged from 150 to 228 mmol/L in survivors of acute salt overdosage, while levels of 153–255 mmol/L have been observed in fatalities. Vitreous humor is considered to be a better postmortem specimen than postmortem serum for assessing sodium involvement in a death.[13][14]
Cause
Common causes of hypernatremia include:[8]
Low volume
In those with low volume or hypovolemia:
- Inadequate intake of free water associated with total body sodium depletion. Typically in elderly or otherwise disabled patients who are unable to take in water as their thirst dictates and also are sodium depleted. This is the most common cause of hypernatremia.
- Excessive losses of water from the urinary tract – which may be caused by glycosuria, or other osmotic diuretics (e.g., mannitol) – leads to a combination of sodium and free water losses.
- Water losses associated with extreme sweating.
- Severe watery diarrhea (viral gastroenteritis).
Normal volume
In those with normal volume or euvolemia:
- Excessive excretion of water from the kidneys caused by antidiuretic hormone from the pituitary gland, or impaired responsiveness of the kidneys to it.[15]
High volume
In those with high volume or hypervolemia:
- Intake of a hypertonic fluid (a fluid with a higher concentration of solutes than the remainder of the body) with restricted free water intake. This is relatively uncommon, though it can occur after a vigorous resuscitation where a patient receives a large volume of a concentrated sodium bicarbonate solution. Ingesting seawater also causes hypernatremia because seawater is hypertonic and free water is not available. There are several recorded cases of forced ingestion of concentrated salt solution in exorcism rituals leading to death.[11]
- Conn's syndromeusually does not lead to hypernatremia unless free water intake is restricted.
Diagnosis
Hypernatremia is diagnosed when a basic metabolic panel blood test demonstrates a sodium concentration higher than 145 mmol/L.
Treatment
The cornerstone of treatment is administration of free water to correct the relative water deficit. Water can be replaced orally or
See also
References
- ^ PMID 16565125.
- ^ PMID 15982544.
- ^ PMID 27156758.
- ^ ISBN 9780323263528. Archivedfrom the original on 2017-09-08.
- ]
- ISBN 9780071773638.
- PMID 16713497.
- ^ a b c Lewis, J. L. (March 2013). "Hypernatremia". Merck Manual of Diagnosis and Therapy. Medical Library Association. Archived from the original on 27 December 2015. Retrieved 25 December 2015.
- ^ Department of Health & Human Services, State Government of Victoria, Australia Better Health Channel: Salt Archived 2016-04-02 at the Wayback Machine Last updated: May 2014
- ^ PMID 16565125.
- ^ S2CID 20446209.
- ISBN 9780073256993.
- S2CID 35536508.
- ISBN 9780962652394.
- PMID 24286605.
- PMID 1249688.
- S2CID 3212802.
- PMID 23735849.
- PMID 10816188.
External links
- Sodium at Lab Tests Online