14 June Kalemia Flashcards
What is normal serum potassium?
3.5 to 5.5 mEq/L
Potassium is mostly intracellular or extracellular?
Intracellular
Potassium’s role in muscle contractions?
When potassium leaves the cell, it restores repolarization to the cell, which allows the nerve impulse to progress.
This electrical potential gradient helps generate muscle contractions and regulates the heartbeat.
What is rhabdomyolysis?
Rhabdo occurs when damaged muscle tissue releases its proteins and electrolytes into the blood. These substances can damage the heart and kidneys
3 etiologies for hyperK?
- Increased dietary intake
- Lower urinary excretion
- Internal Shift
Causes of Internal Shift of K?
Acidosis
A-adrenergic stimulation
Hypertonicity
Hyperkalemic periodic paralysis
Drugs/toxins/Herbs
What is pseudohyperK?
laboratory finding where blood potassium levels appear to be elevated but do not accurately reflect the true potassium concentration in the body.
Possible causes of pseudohyperK?
Hemolysis
Thrombocytopenia
Causes of reduced urinary excretion?
Acute / Chronic kidney injury
Reduced distal Na+ and water delivery
Disruption to RAAS
What triggers RAAS and aldosterone release?
Extracellular HyperK and low BP
MOA of aldosterone?
Act on collecting tubules to raise Na+ reabsorption AND K+ excretion
What are disease states or drugs that disrupt RAAS?
Hypoaldosteronism
Aldosterone resistance
Pseudo-hypoaldosteronism
Drugs with HyperK as ADR?
ACE inhibitors
K-sparing diuretics
How does HypoK cause ileus?
Hypokalemia can lower neural conduction to and within ENS, affecting reflexes and GI motility, causing ILEUS.
Can metabolic electrolyte disturbances cause ileus?
Yes!
HypoNa, HypoK, Metabolic acidosis, Hypothyroidism
