Nephro week 2 hypokalemia

What is the range of potassium (extracellular)?

3.5-5.0 mEq/L

What is the range of magnesium

1.6-2.4 mg/dL

What pumps potassium into the cells and sodium out?

Sodium-potassium adenosine triphosphatase (Na+ - K+ - ATPase) pump

What is in the intracellular compartment?

Potassium (60% of body water)

What is in the extracellular compartment?

Sodium (chloride & bicarbonate), 40% of body water

What is the difference between intracellular shift & renal loss/ GI loss

Intracellular shift does not change amount of K+ in TBW while renal loss/ GI loss do

How does aldosterone effect NA+?

Activation increases Na+ reabsorption, K+ wasting/ excretion (hypokalemia)

What happens when aldosterone is inhibited?

Inhibition decreases Na+ reabsorption, K+ spared (hyperkalemia)

What populations have mortality risk for hypokalemia?

Chronic HF, or CKD

Prevalence of hypokalemia in healthy adults?

Nonexistent

What level of K+ causes serious side effects?

≤ 3.0

What are causes of hypokalemia?

Medications, alkalosis, hemodialysis, magnesium deficiency, refeeding syndrome

What is used to replenish K+?

Treat underlying cause, diet, supplements, IV, k+ sparing diuretics

What are aldosterone antagonists?

Spironolactone & eplerenone

What are Na+ channel blockers?

Amiloride & triamterene

What is the dose to prevent hypokalemia?

20 mEq/day

What is the dose to treat hypokalemia?

40-100 mEq (divide does over several days)

K+ repletion special scenarios?

Renal insufficiency (50% reduced dose), oral is preferred, NPO (use IV), Hyom

Beta agonist, catecholamines (albuterol, epinephrine, pseudoephedrine) induced hypokalemia is caused by?

Intracellular shift

Insulin induced hypokalemia is caused by?

Intracellular shift

Thiazide induced hypokalemia is caused by?

Renal loss

Loop diuretic induced hypokalemia is caused by?

Renal loss

Penicillin induced hypokalemia is caused by?

Renal loss

Laxative induced hypokalemia is caused by?

GI loss

Alkalosis induced hypokalemia is caused by?

Intracellular shift & renal loss

Rank potassium treatments from most potent to least?

Potassium chloride (PO/IV), potassium bicarbonate (PO), potassium citrate (PO), potassium gluconate (PO), potassium phosphate (PO/IV). (CBCGP) Connor, buys, cats, greasy, pizza

What are potassium-phos products?

Pts with both hypophosphatemia & hypokalemia. Same amount of phosphorous different amount of potassium

What are ADRs of potassium?

GI side effects (> 40 mEQ use divided dose), abdominal pain, GI ulcer

What’s the difference between CR micro encapsulate K+ tablets & wax ER tablets?

Microencapsulated (disintegrates better, fewer GI erosion), wax (easier to swallow, more GI erosion)

What potassium product is the most common/ efficient?

Potassium chloride (PO/IV), 52% potassium

When is potassium phosphate used?

Pt has hypokalemia & hypophosphatemia

What is given if pt has metabolic acidosis

Potassium acetate (IV)

How to calculate what K+ levels will be for IV?

For every 10 mEq of K+ administered, serum K+ increases by 0.1 mEq/L

What are ADRs of IV K+?

Phlebitis (inflammation of vein at injection site), burning, extravasation (tissue necrosis)

What is the max rate/ conc of the central line IV?

20 mEq/ hr, 0.2 mEq/mL

What is the max rate/ con of the peripheral line?

10 mEq/ hr, 0.1 mEq/mL

What is IV piggy back (IVPB)?

Administered as an infusion

What is IV push?

Administered via syringe (NEVER GIVE K+ this way)

How should K+ IV be given?

IV piggy back (IVPB)

What are causes of hypokalemia?

Aldosterone activation, alkalosis, NA+ K-ATPase activation (B2 agonist, insulin)

What is intracellular potassium concentration?

150 mEq/L