Step I-Send Lots of Labs
Here is what you need:
Serum-electrolytes, osmolality, uric acid (if on diuretics), and you might as well send a TSH and cortisol as well (if you have any suspicion of an endocrine cause)
Urine-UA, urine lytes, urine urea, urine uric acid (if on diuretics), urine osm, urine creatinine
Want to learn more about FENa and FEUrea? Well I have an article for you.
Step II-Treat CNS dysfunction
If the patient is altered, comatose, seizing, or has neurologic findings, then raise the sodium by a little bit
Give 3% saline, 100 ml over 10-60 minutes (2 cc/kg up to a max of 100 cc)
10 minutes later, may repeat X 1
may be given peripherally through any reasonable IV
each 100 ml will raise sodium by ~2 mmol/l
Rules Of 3: 3 ml/kg of 3% saline over 30 mins ( should raise by 4 mmol)
Step III-Hang tight
Rules Of 3: 3 ml/kg of 3% saline over 30 mins ( should raise by 4 mmol)
Step III-Hang tight
Do not feel the need to do anything else, just fluid restrict the patient
Place a foley
Do not feel tempted to give NS
Do not be clever, just fluid restrict and admit.
Patients are at a fall risk with hyponatremia
Get a CT scan if they are still a little wacky
Remember the rules of 6’s (from the Stern article below)
Be incredibly careful when correcting hypokalemia, potassium repletion will raise the Na
Step IV-What to do when you couldn’t follow step III
dDAVP 1-2 mcg IV or SubQ x 1
Consult renal
Consider D5W 6ml/kg over 1 hour in consultation with renal if you have really screwed up