Hyperkalaemia

Question 1

Define Hyperkalaemia

Answer 1

Hyperkalaemia is when serum K+ level > 5.5 mmol/L

Question 2

Mild hyperkalaemia range

Answer 2

5.5 - 6.0 mmol/L

Question 3

Moderate hyperkalaemia range

Answer 3

6.0 - 6.5 mmol/L

Question 4

Severe hyperkalaemia

Answer 4

• > 6.5 mmol/L

Question 5

Meds that increases K+ in serum

Answer 5

• ACE-i
• ARBs
• Digoxin
• Spironolactone

Question 6

Impaired excretion of potassium

Answer 6

AKI
CKD
Medications (ACE-i, ARBs, K+ sparing diuretics, NSAIDs, heparin, trimethoprim, ciclosporin)
Type 4 renal tubular acidosis
Hypoadrenalism (e.g. Addison’s disease)

Question 7

Increased cellular release causes of hyperkalaemia

Answer 7

Metabolic acidosis
Hyperglycaemia
Rhabdomyolysis
Tumour lysis syndrome
Packed red blood cell transfusion
Digoxin toxicity
Beta blockers
Severe burns
Hyperkalaemic periodic paralysis

Question 8

Define Pseudohyperkalaemia

Answer 8

An artifactual increase in potassium in the sample tested

Question 9

Pseudohyperkalaemia causes

Answer 9

• the use of small venepuncture needle
• Prolonged tourniquet time
• Difficult venepuncture
• Delayed specimen processing

Question 10

Hyperkalaemia Sx

Answer 10

Palpitations
Fatigue
Chest pain
Shortness of breath
Paralysis

Question 11

Hyperkalaemia clinical signs

Answer 11

Arrhythmias (e.g. bradycardia)
Reduced muscle power +/- flaccid paralysis
Hyporeflexia

Question 12

How do acidosis increase K+ in the serum

Answer 12

Through the exchanges of H+/K+ via the H+/K+ pump

Question 13

Hyperkalaemia Ix

Answer 13

1. VBG - K+ level, acid-base status, lactate level
2. ECG - assoc. conduction abnormalities
3. UEs - K+, Na+, egfr, Cr

Question 14

Hyperkalaemia ECG findings

Answer 14

• Tented T wave
• flattened P waves
• PR prolongation
• broad QRS

Question 15

Hyperkalaemia Medical Mx steps

Answer 15

1. Myocardium stabilisation
2. K+ shift - drive K+ into the cells
3. Potassium elimination
4. Prevent recurrence

Question 16

1. Myocardium stabilisation in hyperkalaemia

Answer 16

1. IV calcium chloride 10%
   Dose: 5-10ml over 10 minutes
   OR
   IV calcium gluconate 10%
   Dose: 10-20ml over 5-10 minutes

Question 17

Shifting K+ into intracellular spaces Mx

Answer 17

1. IV insulin + dextrose: 10 unit insulin + 50ml 50% dextrose over 15-30mins
   - BM monitoring, 15mins intervals for an hour and then hourly up to 6 hours
2. Salbutamol 10-20mg Nebs
3. NaHCO3 - for severe metabolic acidosis

Question 18

Potassium elimination

Answer 18

1. Oral calcium resonium reduces potassium absorption in the GI tract (this is slow and causes constipation)
2. Haemodialysis

Question 19

Prevent recurrence of hyperkalaemia

Answer 19

• Take a Hx
• Causes of high K+
• Medication use: ACE-I,
• Low K+ diet
• (crystalloid - Plasmolite) K+ concentration is less than pt K+ level therefore creating a K+ gradient for K+ level to shift intracellularly