What is a potential complication of overly rapid correction of hyponatremia?

Rapid correction of hyponatremia can lead to a serious and potentially life-threatening condition known as central pontine myelinolysis. This occurs when the osmotic shifts associated with the rapid increase in sodium levels cause injury to the myelin sheath in certain areas of the brain, particularly the pons. The pons is sensitive to changes in osmolality, and when sodium levels are corrected too quickly, the brain cells may not be able to adapt to the sudden changes in fluid balance, leading to demyelination.

Symptoms of central pontine myelinolysis can range from confusion, difficulties with speech, and movements to more severe outcomes such as locked-in syndrome or even coma. This complication underscores the importance of gradual correction of sodium levels in patients with hyponatremia, with recommendations often suggesting a correction rate of no more than 8-12 mEq/L per day to minimize the risk of complications like this.