You are transporting an elderly male found unresponsive with seizure activity in a sauna. He has received Keppra and Midazolam, two liters of normal saline. Na 110, Cl 95, BUN 34, Cr 2.0, K 3.4, HCO3 24, Glu 78. You know that this patient requires

• A. Administration of a hypertonic saline solution
• B. Administration of intravenous benzodiazepine escalation
• C. Continuous cooling measures
• D. No intervention pending labs

Answer: (A)

Severe symptomatic hyponatremia with neurologic symptoms is treated by rapid correction of the sodium with hypertonic saline. When sodium falls this low (110 mEq/L) the brain swells, leading to seizures and potential brain injury. Administering a small amount of hypertonic saline (such as 3% NaCl) raises extracellular osmolality quickly, drawing water out of swollen brain cells and reducing cerebral edema, which helps stop seizure activity and protects the brain. This is the most urgent intervention in this scenario because the seizures are driven by a dangerous electrolyte disturbance, not just heat exposure.

Normal saline or additional IV benzodiazepines would not address the underlying cause quickly enough and could risk worsening the hyponatremia or delaying definitive treatment. Cooling measures matter in heat illness, but correcting the hyponatremia takes priority to control the neurologic injury. Delaying intervention while awaiting labs would miss the window to prevent further brain injury.

In practice, give prompt 3% saline with careful monitoring, aiming to raise the sodium by about 4–6 mEq/L initially, then continue with gradual correction under frequent electrolyte checks to avoid overcorrection and osmotic demyelination. Also monitor potassium (which is low here) and other vitals, and manage cooling and airway as needed.