RENAL

Ask the student(s) to suggest what would be considered a normal and abnormal potassium level. Discuss when this becomes clinically significant and ask students to suggest definitions of mild, moderate and severe hypokalaemia and hyperkalaemia.

Confirm/clarify the broadly accepted ranges of mild, moderate and severe hypokalaemia and hyperkalaemia.

Discuss key ECG changes that may be seen in each condition.

Ask the student(s) to take a brief focused history to determine precipitating factors for potassium imbalances e.g. medications, renal disease, excessive supplementation and for symptoms and signs of hypo and hyperkalaemia.

If appropriate, ask the student(s) to examine the patient to look for key signs of hypo and hyperkalaemia.

Ask the student(s) to present their findings. Feedback on presentation style (max 1 minute). Discuss:

• What are the possible causes for hypo/hyperkalaemia in this patient?
• What is the most likely cause?
• What other investigations may be useful? (e.g. magnesium, cortisol, repeat potassium, ECG)

Discuss causes of hyper and hypokalaemia. Attempt to categorise them e.g. using a surgical sieve, using physiological mechanisms (e.g. too much potassium intake, not enough being excreted).

Ask the student(s) to view the ECGs below. Ask them to:

• Identify the key abnormalities.
• Suggest whether they are likely caused by hypo or hyperkalaemia.

Ask the student(s) to review the patient's drug chart to identify any drugs that may cause potassium imbalances. Discuss the appropriate management with each of the medications listed below.

If no drug chart is available, use the example below.

Ask the students to review the management of the patient they have seen.

For hyperkalaemia, discuss:

• What are the treatments available?
• When might each one be indicated? How does treatment vary with severity?
• What is the mechanism of action of the treatment?
• What further management should be considered? (stopping drugs, low K+ diet, calcium resonium)
• When might the renal team need to be involved in the patient's care?
• How might we prevent recurrence?

Ask the student(s) to prescribe calcium gluconate, salbutamol nebulisers and insulin and dextrose on a drug chart.

For hypokalaemia, discuss:

• What replacement strategies are available? Ask students to find the refeeding or hypokalaemia guidelines.
• What is the maximum rate of IV potassium replacement?

Ask the student(s) to prescribe some oral and IV potassium replacement on the drug chart.

1. https://geekymedics.com/hyperkalaemia/
2. https://litfl.com/hypokalaemia/
3. https://www.bmj.com/content/347/bmj.f5137