Electrolyte Imbalances Flashcards
What are causes of hypocalcaemia?
- Vit D deficiency
- CKD
- Acute pancreatitis
How is hypocalcaemia managed?
- Oral calcium carbonate if mild
- IV calcium gluconate when severe (<1.9/seizures)
- ECG monitoring
How does hypocalcaemia present?
- Muscle twitching, cramps and spasms
- Prolonged QT inverval
- Trousseau sign: carpal spasm when the brachial artery is occluded by inflating BP cuff and maintaining above systolic
- Chvostek sign: tapping over parotid causes facial twitch
What causes hypercalcaemia?
- primary hyperparathyroidism
- malignancy e.g. lung, myeloma
What is the key diagnostic investigation for hypercalcaemia?
PTH levels
How does hypercalcaemia present?
- Bone pain
- Abdominal pain
- Renal stones
- Depression
- Drowsiness
- Delirium
- Muscle weakness
How is hypercalcaemia managed?
- IV Saline
- IV Bisphosphonates
What causes hyponatraemia?
- SIADH
- Hypothyroidism
- Thiazides
- Diarrhoea/Vomiting
- Psychogenic polydipsia
How is hyponatraemia managed?
If hypovalaemia: IV fluids
If euvolaemic: Treat underlying cause e.g SIADH by fluid restriction
What is the big risk with severe hyponatraemia?
Central pontine demyelination
What are causes of hypernatraemia?
- Dehydration
- Osmotic diuresis
- Diabetes insipidus
How is hypernatremia managed?
Rehydration with IV Saline/Hartmann’s - should not correct faster than 10mmol/24 hours due to risk of cerebral oedema
What causes hypokalaemia?
- Diuretics
- Renal tubular acidosis
- Cushings/Conns
- Diarrhoea/vomiting
How does hypokalaemia present?
- Muscle weakness
- Hypotonia
- ECG shows: U waves, small t waves, prolonged PR, ST depression
How is hypokalaemia managed?
- Treat cause
- Oral supplementation if mild
- IV fluid if severe with cardiac monitoring
What causes hyperkalaemia?
- AKI
- ACE/Spironolactone
- Addisons
- Rhadbomyolysis
What is the classification for hyperkalaemia?
Mild - 5.5 - 5.9
Moderate: 6 - 6.4
Severe: >6.5
How does hyperkalaemia show on ECG?
- Tall T waves
- Absent p waves
- broad QRS
- Sinusoidal pattern
How is hyperkalaemia managed?
- IV Calcium gluconate
- Insulin/Dextrose solution
- Nebulised salbutamol
- Calcium resonium -> oral or enema which is more effective
- Dialysis if persistent
Management of severe hyponatraemia (<120)
Hypertonic saline (3% NaCl)
