potassium disorders Flashcards
hyperkalemia serum
serum potassium > 5 mEq/L
hyperkalemia is due to
increased K intake
decreased K excretion
increased K shift ECF
pseudohyperkalemia is due to
hemolysis from venipuncture
decreased renal K excretion is due to
acute or chronic kidney disease
endocrine causes of hyperkalemia
hypoaldoteronism
rx cause of hyperkalemia
potassium sparing diuretics ACE I ARBs NSAIDs TMPSMX
symptoms of hyperkalemia
weakness
paralysis
arrhythmias
ileus
ECG showing hyperkalemia features
peaked T waves then sine wave
management of mild hyperkalemia
recheck K+ levels to rule out hemolysis
management of significantly elevated K or ECG changes
IV calcium gluconate to stabilize myocardium
insulin and glucose
beta 2 agonists
type IV RTA can cause
hyperkalemia
what does increased K concentration do to cell membrane?
resting membrane potential becomes less negative and increases excitability
ABG for hyperkalemia
metabolic acidosis (high K, low pH)
albuterol can treat
hyperkalemia
next step in treatment of severe hyperkalemia after IV calcium gluconate
parenteral insulin with glucose
K concentration is ____ in the cell and ____ outside the cell
high
low
potassium in mainly reabsorbed in the
PCT
non-renal causes of hypokalemia
vomiting
diarrhea
renal causes of hypokalemia
diuretics
hyperaldosteronism
hypomagnesemia
type I and II RTA
what can cause K to shift into cell?
insulin excess
alkalosis
______ aldosterone causes hypokalemia
increased
how does hypomagnesemia cause hypokalemia
low Mg disrupts NaK pump leading to increase K secretion by principal cells
this secretion is unchecked because Mg usually regulates secretion which cannot occur in hypomagnesemia
=excessive renal K wasting
hypokalemia with normal or lowBP
Barter syndrome or Gitelman syndrome
hypokalemia with high BP
Liddle syndrome
Barter Syndrome inhibits ____ leading to _____
NKCC2
hypokalemia because NaKand Cl cannot be absorbed
Gitelman Syndrome inhibits ____ leading to _____
NCC
hypokalemia
hypokalemia symptoms
severe muscle weakness decreased deep tendon reflexes ileus polyuria rhabdomyolysis hypotension arrythmias
hypokalemia serum
K <3.5 mEq/L
alkalosis can cause ____ ECF K concentration
decreased
hypokalemia treatment
oral KCl, IV if severe
low ____ interferes with K repletion
Mg
diagnostic test for hypokalemia
serum electrolytes
increased insulin can ____ K
decrease
laxative abuse can cause
hypokalemia
