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Flashcards in K+ Deck (16):
1

K+ balance

Normal body stores in adult = 3000-4000 meq
98% is INTRACELLULAR
K decrease by 1 meq reflects 200-400 meq total body deficit

2

Function of K+

- protein and glycogen synthesis
- maintains RMP
- determines membrane excitability

3

Symptoms of Low and High K+

relates to the inability to generate APs in muscles
- cramps
muscle weakness
EKG changes and cardiac arrhythmias

4

EKG changes of HYPOkalemia

PR interval prolongation
ST depression
Flattened/inverted T waves
U-waves
QRS widening

5

EKG changes of HYPERkalemia

PR interval prolongation
Elevated T waves
Widened QRS

6

K+ distributes rapidly into cells

catecholamines and insulin increase activity of Na/K pumps and uptake into skeletal muscle and liver

7

Acidemia and K

K moves out of cell as H+ is buffered into cells

8

Alkalosis and K

K moves into cells and H+ is buffered out of cells

9

Determinants of K secretion by kidney

1. Plasma [K]
2. Urine flow in distal tubule
3. Aldosterone

10

Hypokalemia due to increased entry into cells

Metabolic alkalosis
Hyperinsulinemia
Increased catecholamines

11

Hypokalemia due to GI loss

N/V, diarrhea, NG tube suction

12

Hypokalemia due to urinary loss

Diuretics, hypercalcemia, aldosterone, hypomagnesemia

13

Low urinary K with Hypokalemia

GI Loss
- acidosis = lower GI, laxatives/villous adenoma
- alkalosis - upper GI, vomitting

14

High urinary K with Hypokalemia

Kidney Loss
- acidosis = ketoacidosis
- alkalosis
- normotensive = vomitting
- hypertensive = renin mediated

15

Hyperkalemia causes

Renal failure
effective circulating volume depletion
hypoaldosteronism --> decreased renin-angiotensin

16

Treatment of hyperkalemia

Check EKG changes
- treat immediately if EKG changes present