Fluid And Electrolytes

Question 1

Treatment of hyperkalemia. What is treatment aim?

Answer 1

calcium gluconate to stabilize cardiomyocyte membranes (or calcium chloride).

Question 2

Pathophysiology hyperkalemia

Answer 2

Normal resting membrane potential -70 mV and is maintained by Na+/K+ ATPase pumps and leaky K+ channels. This allows for the cells to be excitable.
Threshold potential is required to initiate action potential and once at threshold potential inactivation gate close. Afterwards K+ leaves the cell to depolarise the cell and then cell goes back to RMP. But in hyperkalemia there is high concentration outside than in cell so now less K+ leaving the cell so RMP is less negative. New RMP and Na+ gated channels cannot be activated leading to decreased cell excitability.

Question 3

Causes of hyperkalemia

Answer 3

Acute kidney injury
hypoaldosterone
Aldosterone antagonist
NSAIDs, ARBs, Potassium sparing diuretics (Amiloride),
Decreased or no insulin (insulin stimulates Na+/K+ ATPase) therefore lack of insulin means that K+ builds up outside
Digoxin in hypokalaemia it precipitates hyperkalemia
Rhabodomylsis

Question 4

Signs and symptoms of hyperkalemia ( there has been murder in savannah)

Answer 4

Question 5

Management of acute severe hyperkalemia

Answer 5

Calcium chloride 10% or calcium glauconite to stabilise the cardiac muscle.
Insulin + glucose
Salbutamol if indicated
Acidosis: sodium bicarbonate

Question 6

Management in mild hyperkalaemia or moderate hyperkalaemia

Answer 6

Ion-exchange resins

Question 7

What drugs cause hyperkalemia (PANASH causes hyperkalemia)

Answer 7

PANASH causes hyperkalemia:
Potassium supplements
ACE-inhibitors
NSAIDs
Spironolactone
Amiloride
Heparin

Question 8

What drugs cause hypokalemia (DISC with a B cause hypokalemia)

Answer 8

DISC with a B causes hypokalaemia: Diuretics, Insulin, Beta2 antagonist, Corticosteroids.

Question 9

What causes hyponatremia

Answer 9

Antidepressant, desmopressin, carbamazepine, diuretics, lithium

Question 10

Drug that causes hypomagnesia

Answer 10

PPI