Therapeutic relowering of the serum sodium in a patient after excessive correction of hyponatremia.
BACKGROUND
Inappropriate correction of chronic hyponatremia could lead to major neuropathological sequelae. In man, the risk of brain myelinolysis increases strikingly when correction of the serum sodium exceeds 10-15 mEq/l/24 h. No treatment is actually available for this iatrogenic brain injury. However, recent experimental data showed that rapid reinduction of the hyponatremia greatly reduces the incidence of brain damage and death in case of serum sodium overshooting.


METHODS
We tested this rescue manoeuver in a 71-year-old woman with nausea, confusion and severe (SNa 106 mEq/l) chronic hyponatremia related to thiazides. It was associated with hypokalemia (SK: 3.2 mEq/l).


RESULTS
Treatment with isotonic saline produced inappropriately high SNa correction level of +21 mEq/l after the first 24 h. After initial improvement, the neurological status deteriorated after 72 h. Rapid reinduction of the hyponatremia was then ordered. Administration of hypotonic fluids (by oral and i.v. route) combined with dDAVP induced a prompt decline in the SNa (-16 mEq/l/14 h) with a final gradient of correction of deltaSNa +9 mEq/l. This manoeuver was well tolerated without untoward effects. The natremia then progressively normalized and the patient completely recovered without neurological sequelae.


CONCLUSIONS
Hypotonic fluids may be safely administered to decrease the natremia after excessive correction of hyponatremia for potential prevention of myelinolysis.
Research Unit for the Study of Hydromineral Metabolism, Erasmus University Hospital, Free University of Brussels, Belgium.
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Soupart
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Ngassa
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Decaux
D000368:Aged; D001581:Benzothiadiazines; D002908:Chronic Disease; D004232:Diuretics; D005260:Female; D006801:Humans; D006955:Hypernatremia / Q000209:etiology / Q000628:therapy; D007008:Hypokalemia / Q000150:complications; D007010:Hyponatremia / Q000139:chemically induced / Q000150:complications / Q000628:therapy*; D007038:Hypotonic Solutions / Q000627:therapeutic use; D007049:Iatrogenic Disease; D017590:Myelinolysis, Central Pontine / Q000517:prevention & control; D012964:Sodium / Q000097:blood*; D049993:Sodium Chloride Symporter Inhibitors / Q000009:adverse effects
D001581:Benzothiadiazines; D004232:Diuretics; D007038:Hypotonic Solutions; D049993:Sodium Chloride Symporter Inhibitors; D012964:Sodium