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Year 2 Renal > Potassium homeostasis > Flashcards

Flashcards in Potassium homeostasis Deck (24):
1

98% of potassium is intracellular or extracellular?

intracellular

2

what % shift in distribution of potassium can be lethal?

2%

3

what are the causes of hypokalemia?

- decreased intake
- increased entry into cells
- increased GI loss
- increased urinary losses

4

what are the symptoms of hypokalemia?

- muscle weakness
- rhabdomyolysis
- renal dysfunction
- hyperglycemia

5

how does hypokalemia manifest on ECG?

U waves

6

what are the treatment options for hypokalemia?

- treat underlying cause
- oral or IV K+
- KCl, K phos, K citrate, KHCO3, K acetate

7

when administering potassium the IV dose should not exceed what level?

10-20 mmol / hour

8

why use KCl when administering potassium?

- metabolic alkalosis is commonly associated with hypokalemia
- administration of KCl will help both the hypokalemia and the metabolic alkalosis

9

what drugs caused drug-induced hyperkalemia?

- NSAIDs
- ACEI
- aldosterone antagonists
- renin inhibitors

10

what are the EKG manifestations of hyperkalemia? severe hyperkalemia?

- hyperkalemia: peaking and narrowing of the T wave with a short QT interval

- severe hyperkalemia: widening of QRS, decreased amplitude, loss of P wave

11

what is the first change seen on the ECG in a patient with hyperkalemia?

tall peaked and symmetrical T wave

12

what is the best initial therapy for severe hyperkalemia (muscle weakness, EKG changes)?

antagonism of deleterious membrane action

13

what is the dosing for hyperkalemia / calcemia?

10 mL 10% Ca2+ gluconate over 2-5 minutes

14

what does glucose and insulin do to treat hyperkalemia?

shifts potassium into cells by increasing activity of Na/K ATPase

15

what does NaHCO3 do to treat hyperkalemia?

shifts potassium to intracellular space

16

which therapy has the greatest value in hyperkalemic patients with coexisting metabolic acidosis?

NaHCO3

17

NaHCO3 has the greatest value in patients with what concurrent condition?

metabolic acidosis

18

when is NaHCO3 cautioned for hyperkalemia therapy?

volume overload / hypernatremia

19

what do beta agonists do for hyperkalemia?

shift potassium to intracellular space (Na/K ATPase)

20

when are beta agonists cautioned for hyperkalemia therapy?

tachycardia, angina pectoris

21

what do diuretics do for hyperkalemia?

increased urinary potassium losses by increasing urine flow rates

22

what does cation exchange resins do for hyperkalemia?

exchanges K for Na

23

when are cation exchange resins cautioned for hyperkalemia?

- constipation
- bowel injury
- volume overload

24

what is the fastest and most efficient means to lower serum potassium for hyperkalemia? when is it used?

- dialysis

- used when conservative measures fail or are likely to fail