Hyperkalemia Flashcards
4 causes of pseudohyperkalemia? (the K+ is actually normal)
In vitro hemolysis.
Leukocytosis.
Thrombocytosis.
Fist-clenching during blood draw.
Hyperkalemia is bad.
yes,
Is excessive K+ intake alone a common cause of hyperkalemia?
Nope.
3 groups of causes of reduced K+ excretion?
Reduced GFR.
Defective RAAS.
Inadequate distal tubule Na+ / volume flow.
Findings consistent with insufficient aldosterone can either be…
Insufficient aldosterone.
Impaired response to aldosterone.
6+ causes of hyperkalemia caused by abnormal cell shifts?
Insulin deficiency Hypertonicity Metabolic acidosis Drugs Exercise Tissue damage / cell lysis (and Hyperkalemic periodic paralysis....??)
4 clinical manifestations of hyperkalemia?
ECG changes.
Muscle weakness/paralysis.
Parathesias.
Impaired urinary acidification.
ECG changes in hyperkalemia?
Peaked T waves
Prolonged PR.
Loss of P waves.
Prolonged QRS. -> “sine wave” V fibrillation
What ECG changes associated with hyperkalemia should prompt you to treat?
Any changes. The progression to arrhythmia here is unpredictable.
What’s the utility of calculating the Trans-tubular K+ Gradient (TTKG)?
It can give you a better idea of the extent of K+ secretion.
Formula for TTKG?
TTKG = ( urine [K] / plasma [K]) / (Uosm / Posm)
this adjusts for water reabsorption in the collecting duct, in case you were worried
3 steps in treating life-threateningly severe hyperkalemia?
1st: Antagonize cardiac effects.
2nd: Encourage K+ to move into cells.
3rd: Remove K+ from body.
How are the cardiac effects of hyperkalemia antagonized?
Calcium gluconate. (mechanism not clear - but it’s the Ca++ that’s important)
3 drugs that can be used to move K+ into cells in emergencies?
Insulin.
Beta-agonists (nebulized albuterol).
NaHCO3. (not that great… and hypertonicity can make hyperK worse).
3 ways to remove K+ in an emergency?
Loop diuretics.
Cation exchange resin (sodium polystyrene sulfonate, Kayexalate) - makes people poop out the K+ (but it may be more due to sorbitol…).
Hemodialysis.
