Hyperkalaemia

Question 1

What is classified as Hyperkalaemia? What are the different stages?

Answer 1

Different definitons available

• Mild hyperkalaemia: 5.5 to 5.9 mmol/L (5.5 to 5.9 mEq/L)
• Moderate hyperkalaemia: 6.0 to 6.4 mmol/L (6.0 to 6.4 mEq/L)
• Severe hyperkalaemia: ≥6.5 mmol/L (≥6.5 mEq/L).

Classification system that also takes into account ECG changes

Question 2

What can be classified as potentially life-threatening features in hyperkalaemia?

Answer 2

Always depends on context and subjective judgement but some features inclue

• Potassium >6.5 mmol/L
• Moderate hyperkalaemia (>6mmol/L ) and clinically unwell/ rapid rise in potassium
• ECG changes
• bradycardia and shock
• clinical signs and symptoms of hyperkalaemia (flaccid muscle paralysis, muscle weakness)

Question 3

What ECG changes can be seen in hyperkalaemia?

Answer 3

In natural progression:

• tall peaked T waves
• shortened QT interval,
• ST segment depression
• prolonged PR interval
• disappearing P wave
• widening of QRS (progressive QRS widening may be seen with higher levels of hyperkalaemia)
• amplified R wave
• arrhythmias (atrial fibrillation, bradycardia, ventricular tachycardia)

Question 4

What is the indication for administration of calcium gluconate in hyperkalaemia?

Answer 4

In all patients with ECG changes, inlcuding arrythmias

Usually Calcium gluconate 10ml of 10% (duration of effect of calcium is between 30 and 60 minutes)

Question 5

What should be the treatment for hyperkalaemia with life-threatening features?

Answer 5

1.Calcium gluconate if ECG changes
2. Insulin + glucose
2. Salbutamol
3. Investigate cause

If acutely life-threatening, renal disease, rapidly rising (e.g. rhabdomyalisi) or refractory: haemodyalsis for Hyperkalaemia

Question 6

What should be the treatment of hyperkalaemia witout life-threatening features?

Answer 6

1. treatment of underlying cause
2. Consider: cation-exchange resin/polymers, diuretics, sodium bicarbonate or dialysis