Electrolyte Imbalances

Question 1

What is the most common cause of hyponatremia in hospital patients?

Answer 1

Dilutional hyponatremia

- water excess in relation to sodium

Question 2

Describe dilutional hyponatremia

Answer 2

Seen commonly in patients with: heart failure, liver cirrhosis or nephrotic syndrome (kidney can’t excrete free water)

Symptoms tend to occur when there has been a rapid change
- headache
- confusions
- convulsions
- coma
This is due to changes to the osmolality, causing cerebral oedema

Question 3

What are the main causes of dilutional hyponatremia?

Answer 3

Cardiac failure
Liver cirrhosis 
Nephrotic syndrome 
SIADH
Diuretic use

Question 4

What is the management of dilutional hyponatremia?

Answer 4

Fluid restriction - 500 to 1000 mL

Review any diuretic therapy

Question 5

How is acute symptomatic hyponatremia treated?

Answer 5

Correct underlying cause
Restrict fluid intake
Correct any other electrolyte abnormalities
Fluid infusion
- hypertonic saline infused at 1-2 mL/kg/hour raises level by 1mmol
- aim to increase by 8-10 in four hours
- furosemide 40-80mg

Question 6

What are the causes of hyper atresia?

Answer 6

Excess sodium intake

Water loss, in excess of sodium

Question 7

What are the symptoms of hypernatremia?

Answer 7

Nausea
Vomiting
Fever
Confusion

Question 8

How do you manage someone with hypernatremia?

Answer 8

Treat underlying cause
Increase fluid intake - orally or IV with 5% glucose
- correct over 48 hours as it can lead to cerebral oedema

Question 9

What are the main reasons for the development of hyponatremia?

Answer 9

• Relative water loss
• Salt loss in excess of water loss
• Pseudohyponatremia (hyperlipidaemia or hyperproteinaemia leads to low sodium)
• Taking blood from an arm where low sodium is being infused with low sodium fluid