First set of guidelines are on which parameters to be used for differentiating hypotonic hypoantremia?
**They recommend urine osmolarity of a spot urine as the first step( - to be honest, takes a day to come back sometimes) although level 1D evidence
**If the urine osm is <100, it is thought the diagnosis is due to water excess intake( tea and toast, beer potamania) – level 1D evidence
**If the urine osm is >100, then a urine Na is ordered.
**If Urine Na <30, low effective arterial volume as the cause of low Na
**If Urine Na>30, ECF should be assessed, and if diuretics are involved
**They suggest against measuring an ADH level
First hour treatment of hyponatremia of severe symptoms( acute or chronic)
**Prompt IV infusion of hypertonic 3% saline over 20min( 150cc)
**Checking Na levels after 20 min and repeating a second bolus( bolus vs a drip – and bolus was chosen, level evidence 2D)
**Keep repeating till level over 5 mmol/L corrected.
**Consider ICU setting care
Follow up management after 5 mmol/L increase
**Stop IV infusion of 3% saline
**Limiting the rise to not more than 10mmol/l in first 24 hours( evidence 1D)
**Checking Na levels after 6 and 12 hours daily till stable
If no improvement of symptoms after 5mmol/L increase
**Continue 3% infusion with additional increase for 1mmol/l per hour
**Stopping 3% when symptoms improve or if Na increase by 10mmol
**Additional diagnostic workup
**Check Na q 4 hours till 3% has been stopped.
Full report at http://www.ncbi.nlm.nih.gov/pubmed/24569496