Hypo, Hyperntraemia

Question 1

Beyond what plasma sodium concentration do we classify as Hypernatraemia?

List 5 causes

Answer 1

140mmol/L (This condition can suggest dehydration)

• Osmotic diuresis (uncontrolled diabetes)
• Fluid loss without replacement (Sweat, Burns, Vomit)
• Diabetes Insipidus
• Incorrect IV Fluid replacement
• Primary Aldosteronism (Causes more ENaC channels)

Question 2

Below what serum Na concentration do we classify Hyponatraemia?

What is it usually due to?

Answer 2

130-135mmol/L

Usually due to increase in water

Question 3

Describe the symptoms of Hyper and Hyponatraemia

Answer 3

Dependent on severity and rate of onset

Neurological: Agitation, Nausea, Focal neurology, Coma

Question 4

List some causes of Hyponatraemia due to Fluid loss or Na loss

Answer 4

Due to fluid loss;

• Diuretics (mainly thiazides)
• H2O overload/ retention
• Increased ADH secretion

Due to True Na+ loss;

• Diarrhoea and Vomiting
• Renal failure/ Diuretics
• Peritonitis
• Burns (losing water too)

Question 5

List some causes of Hyponatraemia due to ADH secretion

Answer 5

• Heart failure
• Kidney disease
• Liver disease
• Medications (Thiazides, ACE Inhibitors, PPIs, Loop Diuretics)

Question 6

What are 2 treatments of Hyponatraemia

What can happen if we correct hyponatraemia too rapidly?

Answer 6

• Fluid restriction (nearly always works)
• Infuse hypertonic saline + Furosemide
• Pontine demyelination (Neurons swell)