Potassium Balance/disorders

Question 1

Normal potassium intake for a steady state?

Answer 1

60-80mmol/d

Question 2

Renal excretion of potassium is?

Answer 2

50-65mmol/d

Question 3

Stool excretion of potassium is?

Answer 3

10-15mmol/d

Question 4

normal serum potassium concentration range?

Answer 4

3.5-5.5mmol/l

Question 5

Hypokalaemia is?

Answer 5

Serum potassium level <3.5mmol/l

Question 6

hyperkalaemia is?

Answer 6

Serum potassium level >5.0mmol/l

Question 7

What percent of total body potassium is intracellular?

Answer 7

98%

Question 8

The intracellular potassium level is maintained by?

Answer 8

Na/K/ATPase pump

Question 9

What organ is primarily responsible for potassium regulation?

Answer 9

The kidney

Question 10

The majority of the potassium filtered(~500mmol) is reabsorbed in what part of the kidney?

Answer 10

The proximal tubule

Question 11

The control of potassium section primarily occurs at what part of the kidney?

Answer 11

The cortical collecting duct

Question 12

Potassium section is dependent on?

Answer 12

1. Delivery of sodium and water to the cortical collecting duct.
2. The action of aldosterone

Question 13

What is the action of aldosterone in the kidney(CCD)?

Answer 13

1. Increased sodium reabsorption from lumen.
   2.promotes potassium secretion into the lumen.
   Thus restoring neutrality.

Question 14

GI potassium excretion is?

Answer 14

10-15mmol/ d

Question 15

Increased GI excretion of potassium occurs in?

Answer 15

Chronic rental failure

Question 16

What are the indications for potassium level check?

Answer 16

1. Patients with cardiac dxs
2. Patients receiving drugs that may affect serum potassium level
3. Patients with diabetes mellitus
4. Patients with major fluid and electrolyte fluxes
5. Patients with renal impairment
6. Patients with weakness of unknown aetiology

Question 17

Drugs that affect potassium levels include?

Answer 17

ACE inhibitors

NSAIDS

Question 18

Effect of systemic acidosis on potassium level?

Answer 18

It promotes the exit of potassium from the cells into the extracellular fluid thus increasing serum potassium level

Question 19

Effect of insulin on potassium levels

Answer 19

It drives potassium into the cell thus decreasing serum potassium levels

Question 20

how do you monitor serum potassium level in diabetic patients?

Answer 20

2-4hourly

Question 21

Fluid and electrolyte fluxes can be seen in what kind of patients

Answer 21

Patients receiving large volume of IV

Patients with severe diarrhoea

Question 22

What are the two major classes of Disorders orders of potassium balance?

Answer 22

Hyperkalemia

Hypokalemia

Question 23

Hyperkalemia is often asymptomatic but the primary risk is of ——- and ——-

Answer 23

Cardiac arrhythmias amd sudden death

Question 24

What are the causes of hyperkalemia?

Answer 24

Pseudohyperkalemia
Redistribution
Intake
Renal retention
Hypoaldosteronism
Drugs..frussemide and NSAIDs

Question 25

What’s the reference interval for the different stages of hyperkalemia

Answer 25

Mild 5.5-6.5mEq/l
Moderate 6.5-8.0mEq/l
Severe>8.0mEq/l

Question 26

ECG changes for mild hyperkalemia?

Answer 26

Peaked T wave

Prolonged PR segment

Question 27

ECG changes for moderate hyperkalemia?

Answer 27

Loss of P wave
Prolonged QRS complex
ST segment elevation
Ectopic beats and escape rhythms

Question 28

ECG changes for severe hyperkalemia?

Answer 28

Progressive widening of QRS complex
Sine wave
Ventricular fibrillation
Asystole
Axis deviations
Bundle branch blocks
Fascicular blocks

Question 29

What are the five key steps in the treatment of hyperkalemia?

Answer 29

Step1: protect the heart, intravenous calcium salts
Step2: shift potassium into the cell
Step3: remove potassium from the body
Step4: blood monitoring of potassium and glucose