Hyperkalaemia Flashcards
Define hyperkalaemia
Blood potassium >6.5
What is the first priority in treatment of hyperkalaemia?
Why?
Calcium gluconate!!
Reduces excitibility of the heart muscle, reducing the risk of arrhythmias
What dose of calcium gluconate should be given?
10 ml 10% calcium gluconate bolus IV
What should be given after calcium gluconate?
Salbutamol 5mg neb Insulin dextrose (10 units ACTRAPID insulin in 50ml of 50% dextrose IV)
Why are salbutamol and insulin dextrose given?
Drives K+ into cells
Causes of hyperkalaemia: drugs
Potassium-sparing diuretics ACEi ARBs Spironolactone Ciclosporin NSAIDs Trimethoprim Beta blockers Nicorandil Heparin
Causes of hyperkalaemia: metabolic
Metabolic acidosis (H+ and K+ ions compete with each other for exchange of Na+)
Addison’s disease: lack of aldosterone
Causes of hyperkalaemia: excessive release from cells
Tissue necrosis (burns, rhabdomyolysis, trauma)
Massive haemolysis (e.g. ABO incompatibility)
Low insulin levels (e.g. DKA)
Causes of hyperkalaemia: muscle ad blood
Rhabdomyolysis
Massive blood transfusion
Hyperkalaemia on ECG
Flattened P waves
Broad QRS
Tall tented T waves
Sine wave > VT
Potassium physiology:
How is potassium moved into ICF?
Insulin
Beta agonists
Aldosterone
Potassium phyiology: how is potassium moved into ECF?
Increased osmolality
Alpha agonists + Beta blockers
Acidaemia
Intense exercise
What serum K+ level indicated hyperkalaemia?
> 5.5
What K+ value increases the risk of arrhythmias?
> 6.5
