Hyperkalemia and Hypokalemia (Exam 4)

Question 1

Hyperkalemia is serum potassium > ____

Answer 1

5.0mEq/L

Question 2

Where is most total body calcium stored?

Answer 2

Intracellular

Question 3

3 broad causes of hyperkalemia

Answer 3

Decreased K+ excretion
Increased K+ intake
Intracellular to extracellular shifts of K+

Question 4

Falsely high K+ is called ______. Name some causes of it?

Answer 4

pseudohyperkalemia:
Mechanical trauma from venipuncture
cooling or deterioration of sample
thrombocytosis
severe leukocytosis

Question 5

Causes of decreased excretion of K+?

Answer 5

Renal failure
hypovolemia
hypoaldosteronism

Question 6

Causes of intracellular to extracellular shift of K+?

Answer 6

Any breakdown/lysis of cells
Acidosis
Insulin deficiency or resistance

Question 7

A lot of meds can cause hyperkalemia. Name some of them.

Answer 7

ACEIs****
ARBs****
K+ sparing diuretics ****(spironolactone)
Bactrim****
Beta blockers
Digitalis
succinylcholine
amiloride
K+ supplements

Question 8

What affect of does hyperkalemia have on the heart?

Answer 8

Increases the resting membrane potential of the cardiac myocyte causing membrane excitability.

Question 9

Symptoms of hyperkalemia?

Answer 9

Usually asymptomatic, can have vague and varied symptoms.

Question 10

What diagnostics might you order in a patient with hyperkalemia?

Answer 10

BMP to assess renal function
EKG
ABG if suspecting acidosis

Question 11

What EKG changes are seen in hyperkalemia?

What serum potassium do they correspond to?

Answer 11

Peaked T waves - 5.5-6.5
Flattened P waves with prolonged PR interval or absent P waves 6.5-7.5
Wide QRS 7-8
Sine wave pattern - >8.0

Question 12

Which of the following EKG changes makes you shit you pants the most?

a) Prominent U wave
b) Diffuse ST segment elevation
c) Peaked T waves
d) Sine wave pattern

Answer 12

d) sine wave pattern

Question 13

What level of hyperkalemia is considered an emergency in an otherwise healthy patient?

Answer 13

> 6.5

Question 14

A serum potassium of >5.5 is considered an ermegency if the patient has ?

Answer 14

Significant renal impairment
Ongoing tissue breakdown
Ongoing K+ absorption
Significant acidosis

Question 15

What is the first pharmacologic therapy you would use in a hyperkalemic patient with EKG changes?

Answer 15

IV calcium gluconate

Question 16

Oh shit, your tech just spilled the last dose of IV calcium gluconate. What pharmacologic therapies will drive potassium back into the cell to buy you some time until you can get more calcium gluconate from the nearest hospital?

Answer 16

Insulin+glucose
Beta-2 adrenergic agonists (albuterol)
IV sodium bicarbonate.

Question 17

What does calcium gluconate do?

Answer 17

Stabilizes the cardiac cell membranes

Question 18

What pharmacologic therapies serve to remove potassium from the body?

Answer 18

GI cation exchangers (kayexalate, patiromer)
Loop diuretics (lasix)

Question 19

hypokalemia is serum potassium below ____

Answer 19

3.5

Question 20

What are 2 broad categories of things that cause hypokalemia?

Answer 20

Increased loss

Movement of K from blood to intracellular compartment

Question 21

What are some causes of increased loss of K?

Answer 21

Renal tubular acidosis
Loop diuretics, hyperaldosteronism
Vomiting/diarrhea

Question 22

What are some causes of movement of K+ from blood to intracellular compartment?

Answer 22

Insulin excess
Beta agonist treatment
Alkalosis

Question 23

When you find out your patient is hypokalemic, what lab do you need to check next?
Why?

Answer 23

Serum magnesium

Need to fix magnesium in order to fix potassium

Question 24

EKG findings in hypokalemia?

Answer 24

Flattened or inverted T waves
More prominent U waves in leads v4-v6
ST depression
QU interval
Arrhythmia

Question 25

Treatment for hypokalemia?

Answer 25

Potassium replacement (either IV or PO)

Question 26

Side effects of administering IV potassium?

Answer 26

Pain and phlebitis