Endo - Hyper and Hypokalaemia Flashcards
Hyperkalaemia - why is it a medical emergency?
Causes cardiac hyperexcitability, leading to ventricular fibrillation and cardiac arrest
Hyperkalaemia - what are some causes?
AKI
Drugs - ACEi, spironolactone, angiotensin 2 receptor blockers, K+ sparing diuretics
Addison’s disease
Metabolic acidosis
Rhadomyolysis
Hyperkalaemia - what are the clinical features?
- Fast, irregular pulse
- Chest pain
- Light headedness
- Palpitations
- Weakness
Hyperkalaemia - what does an ECG show?
Tall tented T waves
Small p waves
Wide QRS complex
Ventricular fibrillation
Hyperkalaemia - what is the staging?
European Resuscitation Council classifies hyperkalaemia:
Mild: 5.5 - 5.9 mmol/L
Moderate: 6.0 - 6.4 mmol/L
Severe: ≥ 6.5 mmol/L
Hyperkalaemia - what is the treatment?
STOP ANY EXACERBATING DRUGS
Stabilisation of cardiac membrane:
1. IV calcium gluconate (does not lower serum K+)
Short term shift in K+ from ECF to ICF compartments:
- Combined insulin/dextrose infusion
- Nebulised salbutamol
Removal of K+ from body:
- Calcium Resonium - oral or enema
- Loop diuretics
- Dialysis
Hypokalaemia - what is it?
Low level of K+ in blood serum
Hypokalaemia - what are the causes of hypokalaemia with alkalosis and acidosis?
Hypo with Alkalosis:
- Vomiting
- Thiazide and loop diuretics
- Cushing’s syndrome
- Conn’s syndrome
Hypo with Acidosis:
- Diarrhoea
- Renal tubular acidosis
- Partially treated DKA
Hypokalaemia - what are the clinical features?
Palpitations
Hypotonia
Muscle weakness
Light headedness
Hyporeflexia
Hypokalaemia - what are the ECG changes?
Small, absent or inverted T waves
Prolonged PR interval
ST depression
U waves
Hypokalaemia - what is the management?
Treat underlying cause, like D+V
If diuretic therapy needed - K+ sparing diuretics
Supplementation:
Mild - Oral K+
Severe - IV K+
