Potassium

Question 1

What is the total body pottassium dependent on

Answer 1

Intake

Losses via kidney and gut

Question 2

What are high potassium foods

Answer 2

Bananas

Pears

Question 3

What happens in the serum after a potassium load

Answer 3

Potassium stimulates ATPase which causes the hormonal release of:

• insulin
• catecholamine
• aldosterone

Question 4

What happens in the urine after a pottasium load

Answer 4

Pottassium stimualtes renal cell utpake and secretion of potassium

Question 5

Where in the nephron is pottassium handled

Answer 5

Proximal tubule (60%)
Loop of henle  (ascending loop) (30%)
Distal tubule (10%)

Question 6

What are the hormones involved in dealing with potassium load

Answer 6

Insulin
Catecholamine
Aldosterone

Question 7

What is the role of insulin and catecholamine

Answer 7

Redistribute the pottassium from the extracellular to intracellular space to lower the serum pottasium

Question 8

How does aldosterone lower the serum potassium

Answer 8

Promote renal excretion of potassium

Question 9

What is the RAAS system when there is fluid depletion

Answer 9

1. Fluid depletion causes underperfusion of renal glomerular (juxtaglomerular appratus)
2. This switches on renin
3. Renin cleaves angiotensin to angiotensin 2
4. Angiotensin 2 stimualtes aldosterone release from the adrenal gland
5. Aldosterone is released
6. Aldosterone causes exchange of sodium for potassium and hydorgen
7. This results in the loss of potassium and gain of sodium to draw water back in

Question 10

What are the effects of an overactive RAAS on potassium

Answer 10

Hypokalaemia

Question 11

When can you have an overactive RAAS

Answer 11

Primary aldosteronism- conns disease
Hypercortisol in cushings disease
Renal artery stenosis- this causes underperfsued juxtaglomerular appatus to release renin

Question 12

What are the effects of an underactive RAAS on potassium

Answer 12

Hyperkalaemia

Question 13

When can you see in overactive RAAS

Answer 13

Adrenal insufficiency
Ace inhibitors
Sprinolactone

Question 14

How does insulin and catecholamine cause upake of potassium

Answer 14

Insulin and catecholamine drive the cellular uptake of potassium by acitvating the sodium pottassium ATPase

Question 15

Where does insulin and catecholamine act

Answer 15

Liver
Skeletal muscle- catecholamine
Adipose tissue- insulin

Question 16

When acid base is disrupted what happens to potassium

Answer 16

Also become distrupted

Question 17

What is the effect of metabolic acidsosis on potassium

Answer 17

Hyperkalaemia

Question 18

What is the effect of metabolic alkalsosis on potassium

Answer 18

Hypokalaemia

Question 19

In metabolic acidosis why is there hyperkalaemia, what happens extra-renal

Answer 19

Acidosis i.e high hydroen cause hydrogen ions to enter the intracellular cells instead of potassium

Question 20

In metabolic acidosis why is there hyperkalameia, what is the action in renal

Answer 20

Hydrogen blocks potassium excretion therefore ECF potassium rises

Question 21

In metabolic alakalosis why is there hypokalaemia

Answer 21

Hydrogen ison move from intracellular cell to ECF as a buffer
Pottassium enters the cell to presever the electrochemical neutrality

Question 22

What are the ECG changes seen in hyperkalaemia

Answer 22

Tall peaked t wave
Widened WRS complex
Loss of p wave

Question 23

In insulin deficiency what happens to potassium

Answer 23

Pottassium moves from ICF to ECF

Question 24

What are the categorical causes of hyperkalaemia

Answer 24

Increased uptake
Reduced excretion of potassium
Altered distribution
Factitious
Drugs

Question 25

What are the causes of increased uptake of potasssium

Answer 25

Oral | Iv therapy

Question 26

What are the causes of reduced excretion for hyperkalaemia

Answer 26

Renal failure Mineralocoticoid deficiency- addisons Tubular defects

Question 27

What are the causes of altered distribution in hyperkalaemia

Answer 27

Acidosis Insulin deficiency Crush injury

Question 28

What drugs can cause hyperkalaemia

Answer 28

Ace inhibitors ARBs Pottassium sparinf diuretics Potassium supplements

Question 29

What are the consequences of hyperkaelmia

Answer 29

Neuromuscular: weakness, paralysis Gi: nausea and vomiting and pain Cardiovascular: conduction defects, arrythmia and cardiac arrest

Question 30

When is it an emergency for hyerpkalemia

Answer 30

When potassium is over 6.5

Question 31

What is the treatment for hyerpkalaemia

Answer 31

Protect the heart: calicum gluconate, ecg monitor, care with patient on digoxin Redistribution of potassium: glucose and insulin, beta agonist, bicarbonate Removal of potassium: loop diuretics, dialysis

Question 32

When is chronic hyperkalaemia caused

Answer 32

By CKD

Question 33

How do we treat chronic hyperkalaemia in CKD

Answer 33

Treat the underyling cause of ckd Low pottasssium diet Treat metabolic acidosis

Question 34

What are the causes of hypokalaemia

Answer 34

GI loss Renal Inadequate intake Redistribution

Question 35

What are the causes of gi loss in hypokalaemia

Answer 35

Fistula Diarhhoe Tumour of the GI tract where bicarbonate is lost

Question 36

What are the renal causes of hypokalaemia

Answer 36

Diuretics Renal tubular acidosis Mineralocorticoid excess- cushings and conns

Question 37

What are the redistribution causes of hypokalaemia

Answer 37

Insulin Alkalosis Salbutamol

Question 38

What are the consequences of hypokalaemia

Answer 38

Skeletal muscle: weakness, paralysis GI: paralytic ileus Kidney: impaired concentrating ability, tubular defects Cardiac: arrhythmia, digoxin toxicity

Question 39

What are the ECG changes in hypokalaemia

Answer 39

``` Flattened t wave St Depression Prominent p wave and prolonged pr interval U waves ```

Question 40

What is the treatment of hypokalaemia

Answer 40

Non urgent Oral treatment-3 bananas Iv treatment