SODIUM
HYPONATRAEMIA
HYPERNATRAEMIA
POTASSIUM
HYPOKALAEMIA
HYPERKALAEMIA
CALCIUM
HYPOCALCAEMIA
HYPERCALCAEMIA
HYPONATRAEMIA
Top
LOOK FOR
Confusion, convulsions, coma
PRECIPITATING FACTORS
Excessive IV with 5% dextrose, water toxicity
Elderly patients, cardiac and renal failure, diabetics, hypothyroidism
Diuretics, vomiting, ileus, diarrhoea
EMERGENCY MANAGEMENT
Exclude factitious cause: hyperglycaemia, mannitol, ethanol, methanol,
ethylene glycol
Correct hypovolaemia with colloid or N Saline
Correct hypervolaemia (CCF, water overload) with diuretic and fluid
restriction, posture, oxygen
Symptomatic hyponatraemia - fitting or coma:
Resuscitation
Slow correction of Na+ over 24-36 hours with 0.9% Saline
Hypertonic saline rarely to correct if Na+ <120mmol/L
and patient severely symptomatic
Frequent monitoring of electrolytes
HYPERNATRAEMIA
Top
LOOK FOR
Pyrexia, confusion, coma
Dehydration, hypovolaemia, tachycardia, hypotension
PRECIPITATING FACTORS
Burns, pyrexia, polyuric renal failure
Vomiting, diarrhoea, mannitol, diuretics
Hypoadrenalism, thyrotoxicosis
Overuse of intravenous sodium bicarbonate
EMERGENCY MANAGEMENT
Restore hypovolaemia with IV colloid or 5% dextrose
1 L water deficit will increase serum Na by 4mmol/L above 145mmol/L
Correct deficit with 5% dextrose or 4% dextrose saline
Slow correction of Na over 24 hours
Adjust fluid regime for insensible losses
Frequent monitoring of urine output and electrolytes
Consider thromboprophylaxis
HYPOKALAEMIA
Top
LOOK FOR
Tachyarrhythmias: AF, SVT, VT, Torsade
ECG changes: prolonged PR, flat T waves, U waves
Ileus, constipation, muscle weakness, ventilatory failure
Metabolic alkalosis
PRECIPITATING FACTORS
Diuretics, vomiting, ileus, diarrhoea, polyuric states
Steroids, bronchodilators, catecholamines, TPN, insulin
Hypovolaemia, dehydration
EMERGENCY MANAGEMENT
Treat underlying cause
If hypovolaemic, give IV colloid 10ml/kg
Give IV KCI if symptomatic (max rate 40 mmol/hr)
Consider MgSO4 5-10mmol IV
Measure electrolytes and blood gases hourly
HYPERKALAEMIA
Top
LOOK FOR
Bradycardia, "sine wave", QRS asystole
ECG changes, peaked T waves, prolonged PR interval
Hypotension, muscle weakness
PRECIPITATING FACTORS
Anuric renal failure, burns, crush injury, spinal injury
Suxamethonium in above patients
Acute myotoxicity
Acidosis, haemolysis
EMERGENCY MANAGEMENT
Exclude artefact: (drip arm tourniquet, haemolysis)
Determined by ECG changes / haemodynamics
Give, in the following order, as necessary:
CaCI2 10ml IV stat (if ECG signs present)
NaHCO3 50ml IV stat
25ml 50% dextrose + 25u insulin
Continuous nebulised salbutamol
Consider dialysis in anuretic patients or if persistent
HYPOCALCAEMIA
Top
LOOK FOR
Tetany, laryngospasm, Chvosteks and Trousseau signs
Confusion, convulsion
ECG: prolonged QTc interval
PRECIPITATING FACTORS
Parathyroidectomy
Early rhabdomyolysis
Massive blood transfusion
EMERGENCY MANAGEMENT
Treat only if symptomatic
Measure ionised Ca++
CaCI2 10ml IV push
Check acid base and electrolytes
HYPERCALCAEMIA
Top
LOOK FOR
Muscle weakness
Drowsiness, coma
PRECIPITATING FACTORS
Hyperparathyroidism
Rhabdomyolysis
Renal failure
Malignancy
EMERGENCY MANAGEMENT
Usually none, treat underlying cause
Maintain adequate hydration and normovolaemia
Diuretics once normovolaemia assured
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