Electrolytes, again

Low Na:
– Hypervol: HF/RF/Liver failure/Nephrotic.
Urine Na will be LOW (under 20). Fluid restrict. Diuretics. If severe: Hypertonic saline.
– Euvol:
Urine Na will be high. Fluid restrict 1l/d. Consider demeoclocyline in euvol.

– Dry: (Raised urea with normal or raised creat).
Urine Na will be HIGH (over 20). Treat with N saline.

Urine osmol is over 500 in dry or euvolaemia.

High plasma Na = vol depletion. Ensure no DKA/HONK. Inspidus? Initially treat with N saline 8-hourly.

Low Na:

Na loss –> volume depletion –> ADH released —> water is retained –> even more low Na.
N + V + headache confusion + spasms/cramps/weakness + LOC.

Fluid-heavy: Failures of heart, liver, nephrotic (kidney).
—> Treat or fluid restrict.

Euvolaemic: SIADH! Steroid deficiency! BRAINS! Exclude artefact (lipids or paraproteins).
—> Fluid restrict. VAPTANS.

Dry: Hypovolaemia (vom, diarrhoea), diuretics, Addison’s (gluco + mineralocorticoid def), pain. (Vol depletion –> ADH! —> dry low Na).
—> Correct SLOWLY!

Low potassium = Diuretics/GI loss.
Cardiac monitoring. Under 2.6? KCl, based on renal function.
Low K+ assoc with Low Mg (give Mg So4 – if both low, replace in same bag).

High potassium = Renal failure. Addison’s (morning serum cortisol or short synacthen).

K+ 6.5 = ECG!
– 10ml 10% Ca gluconate over 10 mins.
– 10 Units Actrapid 50ml of 50% Dextrose IV over 10 mins.
– Then: Insulin/Dex infusion. Ca resonium. Haemodialysis. Neb sabs.

Low Ca2++: Renal failure, Vit D deficiency (like Eloise), low PTH.

– If tingling or under 1.5mMl:
10ml 10% Ca gluconate over 10 mins. (low calcium, high potassium = calcium gluconate).
Then bag of Calcium gluconate (40ml of 10% in 500ml N saline 12 hourly?)

– If no sx: Consider IV Mg need. Calichew D3 BD.

High Ca+:
Check PTH. Any thiazides –> high calcium. REHYDRATE & Palmidronate.

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