Hyperkalemia

Question 1

What is the potassium level range associated with peaked T waves on an ECG?

Answer 1

5.5–6.5 mmol/L

Question 2

What ECG changes occur at a potassium level of 5.5–6.5 mmol/L?

Answer 2

Peaked T waves (due to repolarization abnormalities).

Question 3

What potassium level is associated with progressive atrial paralysis on ECG?

Answer 3

6.5–7.0 mmol/L

Question 4

What ECG changes occur at potassium levels of 6.5–7.0 mmol/L?

Answer 4

progressive atrial paralysis = gradual disappearance of P waves

P wave widening and flattening

PR prolongation

eventual disappearance of P waves.

Question 5

At what potassium level do conduction abnormalities and bradyarrhythmias appear?

Answer 5

7.0–9.0 mmol/L

Question 6

What are the key ECG changes associated with potassium levels of 7.0–9.0 mmol/L?

Answer 6

Bradyarrhythmias (sinus bradycardia, AV block, slow junctional/ventricular escape rhythms), conduction blocks, prolonged QRS interval with bizarre QRS morphology.

Question 7

What potassium level is associated with pre-terminal ECG findings, such as a sine wave appearance?

Answer 7

Greater than 9.0 mmol/L

Question 8

What ECG findings are seen at potassium levels above 9.0 mmol/L?

Answer 8

Sine wave appearance, asystole, ventricular fibrillation, and PEA with bizarre, wide-complex rhythms.