Renal - Potassium

Front 1

Where is the majority of potassium stored?

-intracellular vs extracellular

Back 1

98% is intracellular

--storage in muscle, liver, bone and RBCs

Hint 1

pg 93

Front 2

How do we maintain potassium balance?

-what % is excreted in the stool vs urine (normally)

Back 2

--90% in the urine
--10% in the stool

Hint 2

pg 93

Front 3

What are the two functions responsible for the maintenance of plasma [K]?

Back 3

1. Normal distribution of K between the ICF and ECF

2. Urinary excretion of K added to the ECF from the diet

Hint 3

pg 94

Front 4

What factors increase K uptake by an average cell anywhere in the body? What do they act upon?

Back 4

-- catecholamines
-- insulin
-- hyperkalemia
-- exercise
-- all increase the activity of the Na/K ATPase with the exception of exercise

Hint 4

pg 94/95

Front 5

Abnormalities induced by hypokalemia

Back 5

1. muscle weakness/camps or paralysis
2. cardiac arrhythmias/ST-segment depression/predisposition to digoxin toxicity
3. myalgias/rhabdomyolysis
4. renal dysfunction and pathology
5. endocrine abnormalities

Hint 5

pg 98/99

Front 6

Metabolic acidosis with urinary K wasting

-causes (3)

Back 6

1. salt wasting nephropathy
2. renal tubular acidosis types II and I
3. ketoacidosis

Hint 6

pg 99

Front 7

Hypokalemia wih metabolic alkalosis

-causes (3)

Back 7

1. non-K sparing diuretics
2. vomiting or nasogastric tube suction
3. mineralcorticoid excess

Hint 7

pg 99

Front 8

Hyperkalemia

-etiology (4)

Back 8

1. Pseudohyperkalemia -- bad measurement
2. Increased K load
3. ICF --> ECF shift of K (many causes)
4. Inadequate urinary excretion

Front 9

ICF --> ECF shift of potassium

--causes (8)

Back 9

1. Metabolic acidosis
2. Insulin deficiency and hyperglycemia
3. Hyperosmolar states
4. Beta-adrenergic blockade
5. Severe exercise
6. Digitalis overdose
7. Hyperkalemic periodic paralysis
8. Succinylcholine and arginine HCl

Front 10

Inadequate urinary excretion of potassium

--major cause

Back 10

--Drugs -- NSAIDs, potassium sparing diuretics, ACE inhibitors

Front 11

Hyperkalemia

--clinical manifestations

Back 11

--neuromuscular: paresthesias, weakness, paralysis
--renal: decrease ammonia production and excretion
--endocrine: increased aldosterone and insulin secretion
**cardiac** atrial/ventricular arrhythmias, pacemaker dysfunction, shortened QT interval and elevated T segment

Front 12

Hyperkalemia

--diagnosis (important lab finding)

Back 12

Urine potassium of less than 20mEq/L is indicative of renal defect in responding to hyperkalemia