Hyperkalemia/Hypokalemia Flashcards
Where is K mainly secreted?
principal cell
What 3 factors control K excretion?
- Incresed Na delivery to distal tubule–> increased Na absorption and K + H excretion
- alkalosis-> H reabsorption–>K excretion
- aldosterone
how does plasma tonicity lead to hyperkalemia?
hyperglycemia–> solvent drag–> water pulls K–> hyperkalemia
hyperglycemia and acidosis both cause hyperkalemia…what treats both?
insulin
rapidly producing tumor cells leads to hyperkalemia or hypokalemia?
hypokalemia
When should we check magnesium?
hypokalemia
magnesium blocks K excretion which means hypomagnesium = increased K excretion
When should we check urine chloride?
hypokalemia
metabolic alkalosis
Urine cl
saline responsive hypokalemia from hypovolemia (vomiting, NGT, )
Urine cl > 20 = what?
saline resistant hypokalemia from barters, gitelmans, diuretics
hyperkalemia, Uk
renal causes
hyperkalemia, UK>200, TTKG 8-10
extrarenal causes
hypokalemia, Uk>20, TTKG >7
renal losses
hypokalemia, Uk
GI losses
UK>30, TTKG>7, and hypertensive
primary hyperaldosteronism
secondary hyperaldosteronism
non-aldo mineralcorticoids
Liddle’s
UK>30, TTKG>7, normo/hypotensive, variable acid base?
Mg deficiency
UK>30, TTKG>7, normo/hypotensive, acidemia
DKA
RTA
amphotericin B
UK>30, TTKG>7, normo/hypotensive, alkalosis
Ucl20- diuretics, barter’s, gitelman’s
What are the causes of pseudohyperkalemia
severe leukocytosis/thrombocytosis/erythrocytosis, hemolysis during draw, processing delay, platelets release K during clotting process
EKG of hyper K=
peaked T, wide QRS, prolonged PR interval, shortened QT, absent p waves
Treatment for hyperkalemia?
cardioprtection- calcium gluconate and EKG monitor
K shifts- glucose+insulin, bicarb, B agonis
K net loss- kayexalate, diuretics, dialysis
C BIG KD2
What is the basic algorithm for solving hypokalemia problems?
- defect in internal or external balance?
- renal or extrarenal losses?
- hypertensive or normotensive
EKG of hypokalemia?
flat T
prominent U
depressed ST segment
hyperkalemia neuromuscular changes?
ascending weakness, ileus
what are some clinical manifestations of hypokalemia?
weakness, paralysis, rhabdo, HTN, ileus, nephrogenic DI
Rx: for hypokalemia
not urgent unless complication- monitor EKG, serial [k]
check magnesium
if symptomatic IV KCl 10 meq/fr. 10 meq=.1 increase in [k]
if asymptomatic- oral K
