HyperKalemia and Hypo

Question 1

Normal serum K is?

Answer 1

3.5-5.0 m Eq/L

Question 2

Increased intake of what 2 things can cause hyperkalemia?

Answer 2

PO supplementation, IV potassium.

Question 3

Pseudohyperkalemia from mechanical trauma when what happens?

Answer 3

Can have mechanical trauma from venipuncture. - Can see red serum (giveaway)

This could also be true severe intravascular hemolysis though.

Question 4

Exercise- repeated clenching of the first during venipuncture, cooling of sample or deterioartion of sample, thrombocytosis, and severe leukocytosis can all lead to?

Answer 4

Hyperkalemia

Question 5

What 3 things cause decreased excretion of potassium?

Answer 5

Renal failure(acute or chronic), hypoaldosteronism, hypovolemia.

Question 6

Any breakdown of cells, acidosis, and insulin deficiency/resistance can lead to?

Answer 6

Hyperkalemia

Broken cells release potassium when they lyse

H+ moves from the blood into the cell in exchange for K+

Insulin causes K+ entry into cells.

Question 7

What ion is exchanged for K+ when moved into the cell

Answer 7

H+. Therefore could be hyperkalemic in acidosis

Question 8

Insulin effects K+ how?

Answer 8

Insulin causes K+ entry into cells

With deficiency can cause hyperkalemia

Question 9

ACEi’s ARBs, Bactrim, Beta blockers can all cause?

Answer 9

Hyperkalemia

Question 10

How does potassium cause cardiotoxicity?

Answer 10

Hyperkalemia causes cardiotoxicity by increasing the resting membrane potential of the cardiac myocyte, causing “membrane excitability”

At very high levels, potassium causes the depolarization threshold to rise, leading to overall depressed cardiac function

Question 11

S/S of hyperkalemia?

Answer 11

Vague and varied symptoms, but usually asymptomatic

May have: N/V, palpitations, lethargy, confusion, paresthesias, muscle weakness, paralysis if advanced, arrythmias/death.

Question 12

How should you work up a patient with hyperkalemia?

Answer 12

Repeat potassium level if there’s any doubt about veracity

Serum potassium will be above 5.0

BMP to assess renal function, look at BUN:Cr

EKG

Consider ABG if suspecting acidosis.

Question 13

Describe the sequential order of EKG changes in hyperkalemia.

5. 5-6.5
6. 5-7.5
7. 0-8.0

>8.0

Answer 13

Peaked T wave - K5.5-6.5 mEq/L

Flattened P wave with prolonged PR interval or totally absent P wave. 6.5-7.5

Wide QRS 7.0-8.0

Sine wave pattern portending imminent cardiac arrest. K>8.0

Question 14

Hyperkalemia is considered an emegency when it is above what level? What are other signs that make it an emergency?

Answer 14

Potassium is greater than 6.5

There are clinical s/s of hyperkalemia like muscle weakness, paralysis, arrythmias.

Or above 5.5 and significant renal impairment.

Question 15

What is the treatment for severe hyperkalemia and EKG changes?

Answer 15

IV calcium gluconate. - stabilizes the heart.

Question 16

Insulin + glucose can be used to treat what?

Answer 16

Hyperkalemia, to help drive potassium back into the cell

Question 17

Albuterol can be used to treat what electrolyte imbalance?

Answer 17

Hyperkalemia

Question 18

What are 3 ways you can remove potassium from the body?

Answer 18

GI cation exchanger

Diuretics

Hemodialysis

Question 19

How do GI cation exchanger’s work to treat hyperkalemia?

Answer 19

Bind K+ in the GI tract in exchange for other cations –> excreted in the feces

Kayexalate - sodium polystyrene sulfonate

Patiromer (veltassa)

Question 20

What Diuretic can be used to treat hyperkalemia?

Answer 20

Lasix or other loop diuretic.

Common s/e is hypokalemia

Question 21

Diuretics, Hyperaldosteronism, vomiting, diarrhea, insulin excess, beta agonist treatment, alkalosis, hypomagnesmia, renal tubular acidosis, low calorie diets, can all cause?

Answer 21

Hypokalemia

Question 22

What are ways Potassium is lost in the body?

Answer 22

Renal and GI

Renal - diuretics or hyperaldosteronism

GI - vomiting and diarrhea.

Question 23

Movement of potassium from blood into intracellular compartment occurs in what 3 scenarios?

Answer 23

Insulin excess - insulin helps drive K+ into the cell

Beta agonist treatments - similar to insulin

Alkalosis. H+ is exchanged for K+ for cell entry.

Question 24

If you keep trying to get K+ up and its not working what other elctrolyte should you check?

Answer 24

Magnesium. - Concurrent Mg & K+ losses in diuretics and vomitting.

Question 25

Diuretics, amphotericin B, antipsychotics (risperdal and seroquel), Barium or chloroquine intoxication can cause what?

Answer 25

Hypokalemia.

Question 26

S/s of hypokalemia?

Answer 26

No pathognnomonic presenting s/s

May have muscle fatigue or weakness- often starts in the LE, progresses to the turnk UE, can end in paralaysis

Cramps, rhabdomyolysiss, myoglobinuria

Respiratory muscle weakness –> respiratory failure/death

GI muscle involvement: ileus, constipation, n.v

Question 27

What 3 diagnostic tests should you run when someone has hypokalemia?

Answer 27

BMP

Magnesium

EKG

Question 28

What are the EKG findings of hypokalemia?

Answer 28

Flattened or inverted T waves

More prominent U waves

ST depression

Prolonged QT interval “QU interval”

Arrythmias - V tac, V fib, torsades.

Question 29

If a patient is having cardiac symptoms or their potassium is below 2.5, what should be their treatment?

Answer 29

IV potassium - can cause phlebitis and pain though.

Question 30

If a patient is not having cardiac manifestations or their potassium is above 2.5 then what should be their treatment?

Answer 30

Oral potassium.

Question 31

If a patient has low potassium and low magnesium can you just fix the potassium?

Answer 31

No - magnesium needs to be repleted as well.