potassium

Question 1

typical intake of potassium

Answer 1

100

Question 2

after a meal, potassium is rapidly taken up into cells by

Answer 2

Na/K ATPase

Question 3

extracellular K+

Answer 3

4

Question 4

principal cells contain what for potassium to flow into tubular fluid

Answer 4

K+ channel

Question 5

increased Na delivery to principal cells

Answer 5

lumenal membrane becomes less lumenal positive which causes an increase in K+ secretion

Question 6

furosemide

Answer 6

loop diuretic and inhibits the Na/K/Cl co-transporter and increases Na delivery to the CT

• K+ wasting

Question 7

thiazide diuretic

Answer 7

inhibits the Na/Cl in DT which again causes increase in Na delivery to principal cells

• K+ wasting

Question 8

gitelmans syndrome

Answer 8

characterized by hypotension (increased excretion of NaCl) and hypokalemia

Question 9

amiloride

Answer 9

INHIBITS Na channels leading to a positive lumen and this K+ secretion decreases

• K+ sparing

Question 10

defect in luminal Na/Cl co transporter

Answer 10

Gitelmans

Question 11

potassium shifting into ICF

Answer 11

• insulin
• B-agonists
• catecholamines
• alkalemia

Question 12

potassium shift our of ICF

Answer 12

1. hyperosmolarity
2. exercise
3. cell lysis
4. acedemia
5. glucagon

Question 13

transcellular shifts:

1. sensitive to
2. common in
3. paralysis
4. alkalemia or acidosis
5. associated drugs

Answer 13

1. sensitive to catecholamines
2. hypokalemic periodic paralysis
3. acute alkalemia
4. associated with albuterol and insulin

Question 14

clinical manifestations of hypokalemia

Answer 14

1. muscle weakness and paralysis
2. impaired urinary concentration
3. arrhythmias- increased U wave

Question 15

treatment of hypokalemia

Answer 15

1. underlying cause
2. cautious replacement by oral rout– not overshoot
3. IV replacement with slower administration and not exceed 20 mEq/hr

Question 16

etiologies of hyperkalemia

Answer 16

1. pseudohyperkalemia
2. increased intake
3. decreased urinary excretion
4. transcellular shift/cell lysis

Question 17

pseudohyperkalemia

Answer 17

• hemolysis (think about blood draws)
• leukocytosis
• thrombocytosis

Question 18

decreased excretory capacity of potassium can be from

Answer 18

1. reduced GFR
2. tubular secretory defect with preserved GFR
3. drugs

Question 19

what drugs are associated with hyperkalemia

Answer 19

ACEi, ARBs, K+ sparing, Heparin, NSAIDS

Question 20

reduced GFR and hyperkalemia can be from

Answer 20

1. Acute kidney injury

2. chronic kidney disease

Question 21

tubular secretory defect with preserved GFR that leads to hyperkalemia (3)

Answer 21

1. hyporeninemic hypoaldosteronism
2. addison’s disease
3. tubular dysfunction associated with lupus, sickle cell

Question 22

what type of drug can cause a transcellular shift of K out of cells

Answer 22

Beta blockers

Question 23

clinical manifestations of hyperkalemia

Answer 23

1. muscle weakness and paralysis
2. renal tubular acidosis due to impaired ammoniagenesis
3. EKG abnormality- T wake is peaked

Question 24

treatment of hyperkalemia

Answer 24

1. stabilization of cardiac membranes- giving calcium
2. transfer of potassium into cells
3. removal of potassium from the body