Electrolyte disturbance

Important disturbances

The big uns are:

• Hyponatraemia & Hypernatraemia
• Hypokalaemia & Hyperkalaemia
• Hypocalcaemia & Hypercalcaemia
• Hypomagnesaemia

They mostly have their own pages, just click on them, or for a condensed version, see below.

The Table of Disturbance

	Blood Level	Causes	Symptoms	Investigations	Treatment
Hyponatraemia	<130mmol/l (<120mmol/L is severe)	Kidney: Addison's, renal failure; Water loss: D&V; Oedema: nephrotic syndrome, heart failure; SIADH	confusion, seizures, hypertension, cardiac failure, oedema, anorexia, nausea, weakness	U+E, urinary Na+ (>, urine osmolality	Fluid restriction, treat cause
Hypernatraemia	>145mmol/L	Not enough water: poor intake, diuretics, diabetes insipidus.	thirst, confusion, coma, seizures + signs of dehydration
Hypokalaemia	<3.5 mmol/l	Loss: thiazide and loop diuretics, Cushing's, D&V. Alkalosis causing shift into cells.	At first, muscle weakness and pain from rhabdomylolysis, and constipation. Later paralysis and paraesthaesia.
Hyperkalaemia	>3.5 mmol/l
Hypocalcaemia
Hypercalcaemia
Hypomagnesaemia	<0.7 mmol/l	Diuretics, Alcohol abuse, D&V, Malnutrition, Aminoglycosides (gentamicin, tobramycin) and Post MI.	Arrhythmias, Tetany, Irritability	Blood test. 40% will have hypocalcaemia and 60% will have hypokalaemia.	Oral magnesium, or IV magnesium sulphate (MgSO4)