Hyponatremia

1
Hyponatremia

• Kevin Broder, MD

2
Urgent or not urgent?

• Acute vs Chronic
• Chronic hyponatremia is not an urgent matter
• If acute, urgent or not urgent
• Assume acute changes are urgent
• A change of gt12 per 24 hours is urgent
• If nothing else, change the trend
• Fix the underlying problem before it is urgent

3
First steps

• Consider a recheck
• Saline flush, lab variation, lab errors possible
• Add data points to elucidate the trend
• Consider underlying etiology
• Chronic heart, kidney, or liver disease
• False hyponatremia, pseudohyponatremia
• Assess volume status to narrow the differential

4
Initial Labs

• Consider total protein, lipid panel, glucose
• (example 1 multiple myeloma artificially
  increases the volume thereby artificially
  decreasing lab results that depend on volume)
• (example 2 lipids do the same)
• (example 3 glucose causes an osmotic shift)

5
Round out the lab results

• Check potassium to consider Adrenal Insufficiency
  (low sodium, high potassium, and low blood
  pressure)
• and consider hydrocortisone 100mg IV STAT
• TSH to consider impact of hypothyroidism
• UA because its cheap, fast, easy, and offers
  useful information
• Serum osms and urine osms may be useful
• (urine osms not valid in patients on diuretics)

6
Evaluation of the situation

• What fluids are infusing? Stop hypotonic fluids
• Are there countless empty water bottles?
• Are there suspect medications?
• Is the patient having seizures?
• Are there other signs of neurological
  dysfunction?
• Signs of cognitive dysfunction are emergently
  concerning for central pontine myelinolysis.

7
Initial therapy

• Ordering a recheck may be adequate.
• Consider fluid restriction.
• Consider stopping a diuretic.
• Consider antiemetics or antispasmodics.
• Hypertonic saline is unlikely to be the answer
  but is appropriate given signs of cognitive
  dysfunction attributable to sodium changes.

8
Follow-up

• Sodium should be followed and initial assessment
  challenged if the patient does not respond as
  expected.
• A rapidly increasing sodium is just as concerning
  as a rapidly decreasing sodium.