Successful Management of Life-Threatening Hypernatremia (Na⁺ 186 mmol/L): A Case Report.

Hypernatremia, defined as a serum sodium level greater than 145 mmol/L, is a frequent electrolyte disorder, affecting approximately 1%-3% of hospitalized patients and associated with high morbidity and mortality, with rates exceeding 40% in severe cases. Severe cases, with levels above 180 mmol/L, are generally considered fatal. We describe the case of a 21-year-old bedridden male with a congenital intellectual disability and epilepsy who presented with a three-day history of vomiting, diarrhea, decreased intake, and lethargy. On admission, he was hypotensive, tachycardic, dehydrated, and somnolent, with a serum sodium level of 186 mmol/L. Initial management focused on restoring his intravascular volume with isotonic saline, followed by gradual correction using hypotonic fluids. This was done while ensuring the rate of sodium reduction did not exceed 10-12 mmol/L per day. Electrolytes were monitored closely, and seizure precautions were implemented throughout his treatment. The patient's neurological status improved progressively with the stepwise sodium correction, and he ultimately recovered fully without complications. This case highlights that even extreme hypernatremia can be reversed with careful hemodynamic stabilization, meticulous monitoring of electrolytes, and optimized fluid management, which can lead to favorable outcomes in vulnerable patients.