Biochemistry: U&Es Flashcards
Muscle weakness
Cramps
Cardiac arrhythmia
Ascending paralysis
Hypokalaemia
Causes of hypokalaemia
With HTN:
- Cushing’s syndrome
- Conn’s syndrome (Primary hyperaldosteronism)
- Liddle’s syndrome
Without HTN:
- Diuretics
- Vomiting + Diarrhoea
- RT Acidosis (T1 + T2)
- Bartter’s syndrome (kidney disease)
- Gitelman syndrome (kidney disease)
ECG changes in hypokalaemia
Torsades de pointes U waves T wave inversion ST depression Prolonged QT
Management of hypokalaemia
IV Saline + Potassium (over 4 hours)
ECG changes in hyperkalaemia
Tall-tented T waves (anterior leads)
Small P waves
Wide QRS
Causes of hyperkalaemia
AKI RT Acidosis (T4) Metabolic acidosis Addison's Rhabdomyolysis Blood transfusion Drugs Food
Drug causes of hyperkalaemia
- Diuretics
- ACE Is
- ARBs
- Spironolactone
- Ciclosporins
- Heparin
Food causes of hyperkalaemia
- Bananas
- Kiwis
- Avocados
- Spinach
- Tomato
How to stabilise cardiac membrane during hyperkalaemia
Calcium gluconate
Shifts potassium from extracellular to intracellular
Short term management
Insulin + dextrose infusion
Nebulised salbutamol
Removes potassium from body
Calcium resonium
Loop diuretics
Dialysis
Peri-oral parasthesia
Tetany (muscle twitching, cramps)
Depression
Cataracts
Hypocalcaemia
2 signs seen in hypocalcaemia
Trousseau’s sign
- carpal spasm when taking BP
Chvostek’s sign
- tapping on facial nerve anterior to the ear induces twitching of the facial muscles due to hyper-excitability
ECG changes in hypocalcaemia
Prologned QT
Torsades de pointes
AF
Causes of hypocalcaemia
Osteomalacia (Vit D deficiency) CKD Hypoparathyroidism Pseudo-hypoparathyroidism Rhabdomyolysis Mg deficiency Blood transfusion Acute pancreatitis Respiratory alkalosis
Management of hypocalcaemia
Calcium gluconate (IV) - 10ml of 10% solution over 10 mins
Renal stones Painful bones Abdominal groans Psychiatric moans Thrones (polyuria + polydipsia)
Hypercalcaemia
- Stones, bones, groans, moans and thrones (toilet)
Causes of hypercalcaemia
Primary hyperparathyroidism Malignancy - myeloma - Squamous cell lung cancer Sarcoidosis Hyperthyroidism Thiazide diuretics
Management of hypercalcaemia
- Rehydration (3L per day)
IV 0.9% saline - Biphosphonates
- IV Pamidronate
- Calcitonin (salmon)