Electrolyte imbalances

Question 1

Hyponatraemia

Answer 1

Mild: 130-138
Mod: 120-130
Severe: <120

Question 2

Common causes of hyponatraemia

Answer 2

Pseudohyponatraemia: hyperglycaemia
Renal (excess sodium excretion): renal failure or over-diuresis
Extra-renal: CCF, wounds, GI losses, sweating/fevers, burns, fluid resuscitation with non-sodium containing fluids, SIADH

Question 3

Management of hyponatraemia

Answer 3

1) Fluid restriction (<1.5L)
2) Sodium containing crystalloids (if hypovolaemic)

Do not correct at >10mmol/L per day (AEs: central pontine demyelination, RFs: chronic liver disease, solid organ transplants, severe burns, malnourishment, ongoing GI losses)

Question 4

Hypernatraemia management

Answer 4

Correct fluid imbalance

Question 5

Common causes hypernatraemia

Answer 5

1) Hypovolaemia: GI losses, diaphoresis, excessive use of sodium-containing crystalloids

Question 6

Hypernatraemia complications

Answer 6

Cerebral injury (if any signs altered mental state –> closely monitor with neuro obs)