Sodium is a natural electrolyte that must be kept in careful balance in our bodies because of its critical role in fluid balance.
Serum sodium is the laboratory test used to measure the level of sodium in the blood. Laboratories have a reference range for any test. For most labs, a normal serum sodium level is 135–145 mEq/L. When a serum sodium is below 135 mEq/L, its abnormally low and is described by the diagnosis of hyponatremia.
There are a variety of causes of hyponatremia. Two of the most common ones are:
• Head injuries that cause bleeding or swelling, brain surgery, or the presence of a tumor or other space-occupying lesion of the cranial cavity that can cause hormonal changes that lead to Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH) and resultant hyponatremia.
• Prolonged bouts of vomiting or diarrhea.
One of the earliest signs of hyponatremia is altered mental status. This is a non-specific sign, meaning it’s not unique to hyponatremia. That’s why when friends or family notice that a loved one is acting uncharacteristic or strange, it’s a good idea to recommend a trip to the hospital or doctor’s office to get checked out.
When hyponatremia is left unchecked, it can become deadly. There’s only so much space in our cranial cavities. Hyponatremia causes fluid retention in the brain and that swelling can push and squeeze the brain out the back of the skull, causing herniation syndrome and death. We’ve handled a number of serious medical malpractice cases where that’s happened.
From working on these cases with top nephrology experts, we understand that the medical standard of care requires careful correction of low sodium levels with hypertonic saline because it’s most effective in restoring the sodium fluid balance. Normal saline and hypotonic saline aren’t typically appropriate choices.
While it’s dangerous to have low serum sodium levels, it’s also dangerous to over-correct it or to reverse the low sodium levels too quickly. Instead, the standard of care requires gradual correction with hypertonic saline over hours, with regular repeat sodium serum lab work to measure and titrate the correct treatment.
Overly rapid correction of hyponatremia can cause hypoxia (low oxygen levels) and a dangerous brain injury called osmotic demyelination syndrome (ODS), which was formerly referred to as central pontine myelinolysis (CPM).
In short, when physicians and healthcare professionals know or should know about a patient’s hyponatremia, or low sodium levels, it requires careful attention and management. Leaving it untreated can cause a brain injury. It’s not possible to treat it quickly with an intravenous (IV) fluid bolus of normal saline and send the patient home. Choosing the wrong fluid—typically anything other than hypertonic saline—for fluid replacement can also cause a brain injury.
If you’ve been seriously injured by poor care related to sodium or hyponatremia, then an experienced, top-rated medical malpractice lawyer to discuss your potential case. While we’re based in Houston, Texas, we handle hyponatremia and brain injury cases all over America.