Hypoxemia and Hyponatremia connection

With serum sodium concentration even with a little less than 130 mEq/L,  and subtle symptoms like nausea, vomiting, headache, or confusion - few subsets of patients like:

• Psychosis
• Marathon runners (or athletes)
• Recreational drug users, particularly ecstasy
• Women and children with acute postoperative hyponatremia
• Traumatic brain injury (TBI or intracranial hemorrhage (ICH)
• Recent intracranial surgery 
• Intracranial space-occupying lesion (like a tumor)

- are very prone to quickly develop seizures, respiratory arrest, and permanent or fatal brain damage.

To make things complicated, concurrent hypoxemia, from noncardiogenic pulmonary edema or hypoventilation, exacerbates the hyponatremia-induced cerebral edema. Timely intervention with elevation of the serum sodium concentration to 4 to 6 mEq/L may prevent impending brain herniation.

#neurology

#electrolytes

# neurosurgery

References:

1. Ayus JC, Varon J, Arieff AI. Hyponatremia, cerebral edema, and noncardiogenic pulmonary edema in marathon runners. Ann Intern Med 2000; 132:711.

2. Sterns RH, Nigwekar SU, Hix JK. The treatment of hyponatremia. Semin Nephrol 2009; 29:282.

3. Chawla A, Sterns RH, Nigwekar SU, Cappuccio JD. Mortality and serum sodium: do patients die from or with hyponatremia? Clin J Am Soc Nephrol 2011; 6:960.

4. Seethapathy H, Zhao S, Ouyang T, et al. Severe Hyponatremia Correction, Mortality, and Central Pontine Myelinolysis. NEJM Evid 2023; 2:EVIDoa2300107.