Hypernatraemia

Question 1

Aetiology (think water loss)

Answer 1

Water loss > Sodium loss (sweating when not exercising, fever)
GI losses: Vomiting, drainage, diarrhoea
Hypothalamic lesions = Decrease in ADH -> water loss or thirst centre loss (insufficient intake) = Na+ (can be both)
Renal water loss e.g., nephrogenic diabetes insipidus = Na+ increase
Iatrogenic = IV sodium containing solutions administered to quickly

Question 2

Risk factors

Answer 2

Uncontrolled diabetes
Underlying polyuria disorder
Diuretic therapy
Inability to act on thirst impulse
Age extremes (elderly/neonates)
Nursing home residency

Question 3

Signs and Symptoms (FRIED SALT)

Answer 3

Fever
Restlessness (irritable)
Increased fluid retention
Edema (peripheral pitting)
Decreased urinary output, dry mouth

Skin flushed
Agitated
Low grade fever
Thirst

Question 4

Diagnosis

Answer 4

Bloods: serum sodium levels >145 mmol/L

Question 5

Treatment

Answer 5

Oral IV fluids
Treat underlying cause