potassium

Question 1

Potassium is a major____cation

Answer 1

ICF cation- most of the potassium

Question 2

Potassium serum range is_____.

98% ICF

Answer 2

narrow; little change in potassium has a huge impact because the range is narrow;
small changes can be significant cardiac response)

Question 3

Potassium is excreted by

Answer 3

kidneys

Question 4

if potassium concentration within muscle cells is about 140mEq/L; ECF is 3.5-5.0mEq/L then…

Answer 4

sodium potassium pump in cell membrane maintains this concentration difference by pumping potassium into the cell and sodium out.
B/c ratio of ECF Potassium to ICF potassium is the major factor in the resting membrane potential of nerve and muscle cells, neuromuscular and cardiac functions are commonly affected by potassium imbalances

Question 5

disruption in dynamic equilibrium between ICF and ECF potassium can cause clinical problems.

Answer 5

potassium regulates intracellular osmolality and promotes cellular growth.
potassium is required for glycogen to be deposited in muscle and liver cells

Question 6

diet and meds is source of potassium

Answer 6

fruits, dried fruits, veggies

IV fluids, transfusion of stored hemolyzed blood, meds

Question 7

how does the body regulate potassium

Answer 7

kidneys-primary route for potassium loss (90%)

rest is loss in sweat and stool

Question 8

inverse relationship between sodium and potassium

Answer 8

factors that cause sodium retention (low blood volume, inc aldosterone levels) cause potassium loss in urine
large urine volume= excess loss of potassium in the urine ( a lot of urine= a lot of potassium loss in urine)

Question 9

what happens if there is an impaired kidney function?

Answer 9

retained potassium= toxic levels

Question 10

potassium labs

Answer 10

3.5-5.0 mEq/L

Question 11

hyperkalemia- pts at risk

Answer 11

(high serum potassium) 
impaired renal excretion
shift of K from ICF to ECF 
massive intake of K 
dec renal excretion (RF most common cause of hyperkalemia) 
hypoaldosteronism
K containing salt substitute
K shifting from cells to plasma 
impair entry of potassium into cell (digoxin- higher ECF K concentration)

Question 12

what is the most common cause of hyperkalemia?

Answer 12

RF

Question 13

hyperkalemia- pts at risk: what is hypoaldosteronism?

Answer 13

addison’s disease: adrenal gland insufficiency

adrenal insufficiency with aldosterone deficiency leads to retention of K

Question 14

hyperkalemia- pts at risk: what happens when K shifts from cells to plasma?

Answer 14

k sparing/conserving diuretics;
cell destruction- excessive exercise, catabolism(every time a cell dies, its going to release K)
factors causing K to move from ICF to ECF

Question 15

hyperkalemia- pts at risk: factors causing K to move from ICF to ECF

Answer 15

metabolic acidosis-( exchange of hydrogen ions moving into the cell)
massive cell destruction (burn, tumor, lysis, severe infection)
exercise

Question 16

hyperkalemia- pts at risk: development of hyperkalemia

Answer 16

K-sparing drugs and aldosterone receptor blockers and angiostensin-converting enzyme (ACE) inhibitors

reduces kidney’s ability to excrete potassium

Question 17

hyperkalemia- pts at risk: inc cell excitability( inc concentration of K outside the cell)

Answer 17

as K levels inc, pt experiences cramping leg pain and weakness/paralysis of skeletal muscle

Question 18

hyperkalemia- pts at risk: inc cell excitability( inc concentration of K outside the cell)- cardiac/ meds

Answer 18

most clinically significant for hyperkalemia

altered cardiac function (ask about meds; K sparing meds, ACE inhibitors); dysrhythmias

Question 19

hyperkalemia- pts at risk: inc cell excitability( inc concentration of K outside the cell) - NM

Answer 19

early: muscle twitching, paresthesia in hands, feet and around mouth
later: skeletal muscle weakness (muscle groups)
respiratory muscles affected with very high K levels

Question 20

hyperkalemia- pts at risk: inc cell excitability( inc concentration of K outside the cell) - GI

Answer 20

smooth muscle- hyperactivity

abdominal cramping and diarrhea

Question 21

Hypokalemia- pts at risk

Answer 21

low serum K

inc loss of K from an inc shift of K from ECF to ICF

Question 22

Hypokalemia- pts at risk: GI Loss

Answer 22

most common causes- GI and kidneys
diarrhea, laxative abuse, vomiting, and ileostomy drainage
hyperaldosteronism- adrenal tumor

Question 23

Hypokalemia- pts at risk: Renal Loss

Answer 23

low magnesium level or is diuresing
(esp in pt with elevated aldosterone levels)
aldosterone is released when circulating blood volume is low (causing Na retention in kidneys with a loss of K in urine)
low magnesium stimulates renin release and inc aldosterone levels -> results in K excretion

Question 24

Hypokalemia- pts at risk: Meds

Answer 24

K wasting diuretics (Furosemide- lasix; Hydrochlorothiazide- HCTZ)
corticosteroids
laxative overuse 
steroids 
excessive insulin- cell uptake of K

Question 25

Hypokalemia- pts at risk: Alkalosis

Answer 25

shift of K into cells in exchange for hydrogen | this lowers K in ECF which causes hypokalemia

Question 26

Hypokalemia- Assessment

Answer 26

alters resting membrane potential | results in hyperpolarization and impaired muscle contraction (involves cardiac and muscle functions)

Question 27

Hypokalemia- Assessment: cardiac

Answer 27

most serous clinical problem dysrhythmias- EKG changes( dec BP- orthostatic hypotension); weak thready pulse; inc digoxin toxicity (inc sensitivity of excitable membranes with hypokalemia; always assess latest K levels before administering digoxin; do not administer with low K)

Question 28

Hypokalemia- Assessment: Musculoskeletal

Answer 28

a stronger stimulus is needed; dec excitability of cells; skeletal muscle weakness, fatigue (dec hand grasp, Dec DTR, leg cramps), respiratory muscle weakness(priority assessment)

Question 29

Hypokalemia- Assessment: GI (alteration of smooth muscle function)

Answer 29

dec peristalsis: dec bowel sounds- (abdominal distention; N/V; cramping; constipation); paralytic ileus with severe hypokalemia

Question 30

Hypokalemia- Assessment: Respiratory

Answer 30

priority assessment with hypokalemia: breath sounds; ease of respiratory effort; rate and depth; color of nail beds/mucous membrane weak muscle shallow respiration

Question 31

Hypokalemia- Assessment: nonmucsle function

Answer 31

by impairing insulin secretion: causes hyperglycemia

Question 32

Hyperkalemia- Nsg Dx: risk

Answer 32

activity intolerance- related to lower extremities muscle weakness(fatigue) electrolyte imbalance- excessive retention or cellular release of K (diarrhea- inc peristalsis) injury related to lower extremities muscle weakness and seizures (falls)

Question 33

Hypokalemia- Nsg Dx: risk

Answer 33

activity intolerance- lower extremity muscle weakness electrolyte imbalance- excessive loss of K injury related to muscle weakness and hyporeflexia constipation dc CO

Question 34

Hyperkalemia- Nsg DX: complicaitons

Answer 34

dysrhythmias, CO

Question 35

Hypokalemia- Nsg Dx: complications

Answer 35

dysrhythmia

Question 36

Hyperkalemia- Goals

Answer 36

dec K and treat cause

Question 37

Hyperkalemia- Goals: treatment

Answer 37

eliminate oral and parenteral K intake inc elimination of K (using diuretics, dialysis, and ion exchange resins; insulin with glucose) force potassium from ECF to ICF (using IV administration of regular insulin; IV sodium bicarbonate for correction of acidosis) reverse membrane potential effects of elevated ECF K by administering IV calcium gluconate ( calcium can immediately reverse the membrane excitability)

Question 38

Hyperkalemia- Goals: treatment of mild potassium evaluation

Answer 38

withhold K from diet and IV sources | inc renal K elimination by administering fluids and loops or thiazide diuretics

Question 39

Hyperkalemia- Goals: treatment of moderate

Answer 39

additionally receive one of the treatment to force K into cells; usually IV insulin and glucose

Question 40

Hyperkalemia- Goals: monitor EKGs in clinically significant hyperkalemia

Answer 40

to detect dysrhythmias | dangerous cardiac dysrhythmias should receive IV calcium gluconate immediately

Question 41

Hyperkalemia- Goals: Monitor BP

Answer 41

B/c rapid administration of Ca can cause hypotension

Question 42

Hyperkalemia- Goals: hemodialysis

Answer 42

effective means of removing potassium from the body in the pt with RF

Question 43

Hyperkalemia- Goals: monitor

Answer 43

``` telemetry K lab report bowel sound and stool UOP muscle tone and all body systems affected ```

Question 44

Hypokalemia- Goals: treatment

Answer 44

oral or IV KCl supplements and dietary intake of K EXCEPT: in severe deficiencies; KCl is not given unless there is a urine output of at least 0.5mL/kg of body weight per hour

Question 45

Hypokalemia- Goals: inc K intake

Answer 45

foods(bananas, cantaloupe) PO supplements: can be gastric irritants (K-dur, micro-K, slow-K: dont crush/chew; dont open capsule) intravenous K: monitor UOP; use large vein sites as K b/c is irritating

Question 46

Hypokalemia- Goals: diuretics

Answer 46

use K sparingly (spironoalctone) | hold loop and thiazide diuretics( this inc K excretion)

Question 47

Hypokalemia- Goals: treat constipation

Answer 47

colace miralax metamucil surfak

Question 48

Hypokalemia- Goals: safety measures

Answer 48

skeletal muscle weakness (remove throw rugs, assist with ambulation)

Question 49

Hypokalemia- Goals: monitor

Answer 49

telemetry VS, HR, Respiratory status( critically ill pts should have cardiac monitoring to detect cardiac changes due to K imbalance) serum K levels and UOP (pts on digoxin therapy have an inc risk of toxicity if serum K level is low)