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25 Cards in this Set
- Front
- Back
what % of k+ is extracellular and what is the normal range of k+ of ECF k+? |
95% intracellular & 5% extracellular
(*we measure extracellular NOT intracellular) |
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what are the 4 different ways in which hypokalemia (potassium loss) can come about
What is the worst (most severe) cause of hypokalemia? |
shifting k+ intracellulary from ECF
worst = diarrhea* |
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what causes k+ to shift into the cells from ECF causing a dec in K+? |
insulin (best tx for hyperkalemia, give w glucose)
*(if an acidotic pt has low potassium, need to replace depleted potassium!!) |
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what are some extrarenal k+ losses
what is the MC cause of hypokalemia d/t extrarenal K+ loss? |
diarrhea
infectious diarrhea = MC |
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what is the most important regulator of the body k+ content?
An increased _______ will lead to hypokalemia & likely be accompanied by high BP |
aldosterone
increased aldosterone--> hypokalemia |
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renal k+ loss can also be dt increased flow of distal nephron. what are some causes of this? |
diuretics - furosemide, thiazide |
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what should you suspect if you have refractory hypokalemia despite k+ replacement?
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mg+ depletion |
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What drugs can cause hypokalemia? |
Insulin (esp when treating diabetic ketoacidosis) B2-adrenergic agonists Diuretics (loop--> cause Renal K & Mg loss)
(*hypokalemia also inc risk of digitalis toxicity) |
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what accounts for most of the sx that accompany hypokalemia |
altering the membrane resting potential |
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why do athletes eat bananas before working out |
prevents mild to moderate hypokalemia sx: |
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what are some severe hypokalemia (< 2.5 mEq/L) sx |
flaccid paralysis hypercapnia |
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what would the ekg for a hypokalemic pt look like |
broad T waves |
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is acute or subacute and chronic hypokalemia more dangerous? |
subacute and chronic are the MC and usully not life threatening |
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what is the safest way to tx mild to moderate deficiency hypokalemia |
oral k+
(tx of choice unless ECG changes OR severes!) |
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how is severe hypokalemia treated? what are some stipulations that come with treatment |
must be treated via IV K & correct Mg def* |
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NEVER give k+ at a transfusion rate > ________ |
40 mEq/L per hour
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what organ system can be most dangerously affected by hyperkalemia (> 5.5 mEq/L)?
What symptoms would it cause? |
hypotension, dysrhythmias, ECG changes muscle weakness, lethargy, paralysis, areflexia
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what would hyperkalemia look like on EKG |
tall peaked T waves |
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what are the drugs that can cause hyperkalemia |
K + sparing duretics Captopril (Triamterone, spironolactone) Beta-blockers digoxin succinylcholine
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what is one of the first questions you should ask a hyperkalemic patient |
do they have renal failure?
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what are the causes of hyperkalemia |
renal failure* aldosterone insufficiency (low) Cellular breakdown (tumor-lysis, rhabdomyolysis) hemolysis GI Bleed Salt substitutes containing K+ Ketoacidosis
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What can cause a false hyperkalemia ? |
thrombocytosis leukocytosis prolonged tourniquet time in-vitro hemolysis
(trauma to RBC--> inc intracellular K+) |
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what is the tx of hyperkalemia if serum k+ <6.5 and there are NO ekg signs |
increase k+ excretion through bowels or kidneys or decrease k+ intake |
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what are some treatments for emergent hyperkalemia |
Calcium gluconate (& Na bicarb- FASTEST, but shortest) glucose, insulin Bicarbonate therapy (used if metabolic acidosis*) |
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after emergent treatment, what should you put the patient on |
longer acting therapy with dialysis |