Hyperkalaemia and Hypokalaemia

Question 1

define Hyperkalaemia and Hypokalaemia

Answer 1

High or low levels of potassium in the blood

Question 2

what are the causes of hyperkalaemia?

Answer 2

-increased intake of potassium
-decreased excretion of potassium
-potassium shifted to extracellular
-trauma
-burns

Question 3

what causes Increased intake of potassium?

Answer 3

• IV therapy
  -Increased dietary intake

Question 4

what causes decreased excretion of potassium?

Answer 4

• AKI and CKD
  -Drugs (NSAIDs, spironolactone, ACE inhibitors)
  -Renal tubular acidosis (T4)
  -Addison’s disease

Question 5

What causes Potassium shifted to extracellular?

Answer 5

• Metabolic acidosis/DKA
  -Rhabdomyolysis

Question 6

describe an ECG with hyperkalaemia

Answer 6

-Absent P waves
-Prolonged PR interval
-Tall, tented T-waves
-Wide QRS complex
-Bradycardia

Question 7

what is the presentation of hyperkalaemia?

Answer 7

• Muscle weakness and cramps
  -Paraesthesia
  -Palpitations
  -Tachycardia (arrhythmias)

High K+ decreases the action potential, causing easier depolarisation, and leading to arrhythmias.

Question 8

what is the effect of hyperkalaemia on muscles?

Answer 8

-Smooth muscle cramping
-Skeletal muscle weakness due to over contraction
-Cardiac arrhythmias and arrest

Question 9

what is the treatment of hyperkalaemia when urgent?

Answer 9

Calcium gluconate to stabilise the cardiac membrane, if there are cardiac problems, then insulin dextrose

Question 10

what is the treatment of hyperkalaemia when non urgent?

Answer 10

Insulin (+dextrose)

Question 11

define hypokalaemia

Answer 11

Hypokalaemia ≤ 3.5mmol/L

Question 12

define emergency hypokalaemia

Answer 12

Emergency Hypokalaemia ≤ 3mmol/L

Question 13

define hyperkalaemia

Answer 13

Hyperkalaemia ≥ 5mmol/L

Question 14

define Emergency Hyperkalaemia

Answer 14

Emergency Hyperkalaemia ≥ 6.5mmol/L

Question 15

what are the causes of hypokalaemia?

Answer 15

-Decreased intake of potassium
-Increased excretion of potassium
-potassium shifted to intracellular

Question 16

what causes an increase in excretion of potassium?

Answer 16

-Thiazides + loop diuretics
-Renal disease
- GI loss
-Increased aldosterone

Question 17

what causes potassium to shift to intracellular?

Answer 17

• Insulin
  -Salbutamol (+other drugs)

Question 18

what is the presentation of hypokalaemia?

Answer 18

-Hypotonia
-Hyporeflexia
-Arrhythmias
-Muscle paralysis + rhabdomyolysis

Question 19

What are the effects of hyperkalaemia?

Answer 19

• insulin deficiency due to affected k+ flow
• acidosis ( H+K+ flow affected)
• beta blocker- inhibit pumping of K+ into the cell

Question 20

What are the effects of hypokalaemia?

Answer 20

• insulin excess due to affected k+ flow
• alkalosis ( H+K+ flow affected)
• b2 agonist- increase pumping of K+ into the cell

Question 21

what does an ECG with hypokalaemia have?

Answer 21

Small inverted T waves
Prominent U waves
ST segment depression

Question 22

what is the effect of hypokalaemia on muscles?

Answer 22

-Smooth muscle constipation
-Skeletal muscle weakness and cramps
-Cardiac arrhythmias and palpitations

Question 23

what is the treatment of hypokalaemia?

Answer 23

-K+ replacement*
-Aldosterone antagonist
-Treat underlying cause
-Treat other electrolyte deficiencies