Potassium + HypoKalemia

Question 1

What are normal levels of serum potassium?

Answer 1

3.5 - 5 mg/dL

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Question 2

When does hypokalemia need to be treated with K⁺ repletion?

Answer 2

Serum K⁺ < 3 mg/dL

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Question 3

What types of symptoms are generally seen with hypokalemia?

Answer 3

• generally Cardiac & neuromuscular
• Muscle weakness/Cramps
• Ileus

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Question 4

What EKG sign is seen with hypokalemia?

Answer 4

“U”-waves

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Question 5

What other lab(s) needs to be check when replenishing K⁺ ?

Answer 5

Serum Phosphorus and Mg⁺⁺

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Question 6

What are the causes of Hypokalemia?

Answer 6

3 major categories:
1. Renal loss
2. GI loss
3. Transcellular shift

Question 7

What are facts about Potassium?

Answer 7

• major ICF cation
• less in ECF
• serum K+ reflects transmembrane K+ regulation than total body K+

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Question 8

What increases Potassium secretion?
What decreases Potassium excretion?

Answer 8

Aldosterone causes nephron to secrete K+

Renal failure declines K+ excretion

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Question 9

How to treat Hypokalemia?

Answer 9

treat Underlying cause

Potassium PO > IV (CVC) (May require days)
Generally 10-20meq/L/hr IV

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Question 10

How much does 10 mEq IV of K+ change the serum level?

Answer 10

↑Serum K+ by ~0.1 mmol/L

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