Fluid Balance

Question 0

HypoNa and clinically hypovolaemic.

Causes?

Treatment?

Answer 0

Diarrhoea, vomiting, diuretics, salt losing nephropathy,

0.9 % saline for vol replacement.

Normal saline makes hypoNa worse.

Question 1

Osmolarity Equation

Answer 1

=2(Na +K) + urea + glucose

Question 2

HypoNa and clinically euvolaemic.

Causes?

Treatment?

Answer 2

Hypothyroidism, adrenal insufficiency, SIADH

Fluid restrict and treat underlying cause.

Question 3

HypoNa and clinically hypervolaemic.

Answer 3

Cardiac failure, cirrhosis, nephrotic syndrome

Question 4

HyperNa

Treatment?

Answer 4

5% dextrose to correct water deficit

Normal saline

Serial Na measurements every 4-6 hours.

Question 5

HypoK

1) 3-3.5 treatment?
2) <3 treatment?

Answer 5

1) Oral KCl (sando K).
Recheck K next day

2) IV KCl
Max rate 10mmol per hour for peripheral veins

Question 6

HyperK

Treatment?

Answer 6

10ml 10% Ca gluconate (to stabilise myocardium)

50ml 50% dextrose + 10 units of insulin

Nebulised salbutamol + treat underlying cause

Question 7

HypoK.

Causes?

Answer 7

1. GI LOSS - D&V
2. RENAL LOSS
   - hyperaldosteronism, excess cortisol, osmotic diuresis
   Increased Na delivery to nephron (loop and thiazide diuretics)
3. REDISTRIBUTION INTO CELLS - insulin, beta agonists, alkalosis
4. RARE - renal tubular acidosis, hypoMg

Question 8

HyperK

Causes?

Answer 8

1. EXCESSIVE INTAKE
   - oral, parenteral, blood transfusion
2. TRANSCELLULAR MOVEMENT
   - acidosis, insulin shortage, tissue damage
3. DECREASED EXCRETION
   RF, K sparing diuretics, Addisons, NSAIDS, ACEi