DIABETES AND ENDOCRINE

Identify a suitable patient with either acute or chronic hyponatraemia. Take a focused history from a patient around their presenting complaint, with specific reference to the following areas:

• Review of systems - including any symptoms specifically of hyponatraemia or possible underlying causes

• Drug history - including compliance and newly started medications

If appropriate, perform a focused fluid assessment of the patient. Work systematically to assess specifically for signs of hypo- and hyper-volaemia. You may wish to use this helpful guide to hydration status assessment from Geeky Medics.

Document your findings from your history and examination clearly and systematically.

Once completed, decide if you believe the patient is:

• hypovolaemic (mild to severely dehydrated)

• euvolaemic (well-hydrated)

• hypervolaemic (aka. fluid overloaded)

Write down three key findings from the history and/or examination to justify your choice. Next, consider what further investigations may help to confirm your choice.

Try and think of as many causes of hyponatraemia as you can - group them into broader categories if possible - for example using a surgical sieve.

Considering the patient's history, try to identify the most likely cause(s) of this patient's hyponatraemia. Why do you think this is? Highlight no more than three causes.

Have a look through the patient's notes to see if the clinical team agree with your choice.

Using a hospital computer, find the local guidelines on management of hyponatraemia. Work through these guidelines to familiarise yourself with them. Consider:

• What initial investigations for hyponatraemia do they suggest?

• Based on your fluid assessment and clinical history, what do the guidelines suggest as the initial management of this patient?

• Can you work out why this is?

Ongoing Management

As a junior doctor, you will often be asked to organise ongoing follow up for hyponatraemia in the initial days after admission.

• What follow up do you think is required for this patient, to assess the impact of your initial treatment?

• What are the ideal treatment targets for managing hyponatraemia?

• What are the risks of increasing hyponatraemia too quickly?

• How might you recognise this condition?

Check in the notes and see if the clinical team agree with your ongoing management plan.

Hyponatraemia can often feel like a complicated topic. After reviewing your patient, take a few minutes to consolidate your learning.

If you're struggling with the concept of plasma and urine osmolalities, or want a short refresher on sodium homeostasis, check out this video series on hyponatraemia from HippocraTV or if you prefer a written summary, see this hyponatraemia revision page from Almost a Doctor.

1. https://geekymedics.com/hydration-status-assessment-osce-guide/

2. https://www.youtube.com/watch?v=3QunAw5l0w8

3. https://almostadoctor.co.uk/encyclopedia/sodium