See also The ECG in Electrolyte Disorders
| Approx. ranges for severe abnormality | Mild / Moderate
Symptoms |
Severe symptoms | Urgent treatment (if severe) | Comments |
| Hyperkalaemia
( > 6.5 mmol/L) |
QRS widening symptomatic arrhythmia | CaCl or Calcium gluconate IV bolus
|
Ca2+ temporarily stabilizes membrane action potential | |
| Hypokalaemia
(< 2.6 mmol/L) |
Muscle weakness | Arrhythmia | KCl IV bolus | |
| Hyponatraemia
(< 110 mmol/L) |
Confusion | Seizures or coma | Hypertonic saline bolus | Risk of cerebral pontine myelinolysis and quadriplegia |
| Hypocalcaemia
(Total Ca2+ < 2 mmol/L) |
Paraesthesia > Tetany | Respiratory difficulties, Hypotension, Arrhythmias | CaCl or Calcium gluconate IV | |
| Hypercalcaemia
(Total Ca2+> 3.5 mmol/L) |
Constipation
Fatigue |
Coma | Saline rehydration
|
|
| Hypophosphataemia
( < 0.4mmol/L) |
Arrhythmias
|
IV K2HPO4/K2HPO4 | Risk of dangerous hypocalcaemia | |
| Hyperphosphataemia
|
See hypocalcaemia | Arrhythmias
Resp. failure |
Saline rehydration
Dialyse (if severe hypocalcaemia) |
|
| Hypomagnesaemia
(< 0.5 mmol/L) |
ECG – PR/QRS prolongation | Arrhythmias | MgSO4 IV bolus | Risk of hypotension |
| Hypermagnesaemia
(> 5 mmol/L) |
Hyporeflexia
Confusion |
Arrhythmia
Hypotension Respiratory failure |
CaCl or Calcium gluconate IV bolus | |
| Hypophosphataemia
( < 0.4mmol/L) |
Weakness
Paraethesia Confusion |
Arrhythmias
|
IV K2HPO4/K2HPO4 | Risk of dangerous hypocalcaemia |