Hyponatremia-Hypoxemia connection

Hyponatremia-Hypoxemia connection

A relatively less appreciated fact is the role of hypoxemia in acute hyponatremia. Acute hyponatremia may lead to impending cerebral herniation and causes hypoventilation and/or noncardiogenic pulmonary edema, resulting in hypoxemia. This hypoxemia exacerbates the hyponatremia-induced cerebral edema, setting a fatal vicious cycle. Mild symptoms of nausea, vomiting, headache and confusion can quickly culminate into cerebral herniation when sodium acutely fells below 130 mEq/L.  Fortunately careful correction of sodium by only 4-6 mEq/L can prevent this complication.

High risk patients include psychogenic polydipsia, marathon runners/high exercise, use of ecstasy, acute postoperative hyponatremia particularly in pediatric patients, traumatic brain injury (TBI), recent brain surgery, or brain tumor.

#electrolytes

#neurology

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.