Rhabdomyolysis

Question 1

What is rhabdomyolysis?

Answer 1

A condition skeletal muscle tissue breaks down and releases breakdown products into the blood

Question 2

What is rhabdomyolysis caused by?

Answer 2

Skeletal muscle breakdown

Question 3

What is released into the blood when skeletal muscle is broken down?

Answer 3

Myoglobin
Potassium
Creatinine kinase (CK)
Phosphate

Question 4

What is the most dangerous immediate breakdown product of rhabdomyolysis?

Answer 4

Potassium

Question 5

Why is potassium the most dangerous by product of rhabdomyolysis?

Answer 5

Hyperkalaemia can cause cardiac arrhythmias that can result in a cardiac arrest.

Question 6

What are the main causes of rhabdomyolysis?

Answer 6

Trauma
Medication
Rigorous exercise

Question 7

What forms of trauma are associated with rhabdomyolysis?

Answer 7

Seizures
Coma/collapse (long lie)
Crush injuries

Question 8

What forms of trauma are associated with rhabdomyolysis?

Answer 8

Seizures
Coma/collapse (long lie)
Crush injuries

Question 9

What medication is associated with rhabdomyolysis?

Answer 9

Statins- especially if co-prescribed with clarithromycin

Question 10

How does rhabdomyolysis usually present?

Answer 10

Muscle pain, swelling
Red/brown urine
Acute kidney injury 10-12 hours after initial pain/injury

Question 11

What will be raised in someone with rhabdomyolysis?

Answer 11

elevated creatine kinase (CK)
elevated phosphate
hyperkalaemia

Question 12

What will be low in someone with rhabdomyolysis?

Answer 12

hypocalcaemia (myoglobin binds calcium)

Question 13

What will be present in the urine of someone with rhabdomyolysis?

Answer 13

Myoglobin

Question 14

Why would there be hypocalcaemia in someone with rhabdomyolysis?

Answer 14

Myoglobin binds to calcium

Question 15

Why would the phosphate be elevated in someone with rhabdomyolysis?

Answer 15

Phosphate is released from myocytes

Question 16

What is the most reliable indicator of muscle damage?

Answer 16

Creatinine Kinase- will be minimum 5x normal limit

Question 17

What will the acid-base pattern be of someone with rhabdomyolyisis?

Answer 17

Metabolic acidosis

Question 18

What is the key investigation for rhabdomyolysis?

Answer 18

Measure creatinine kinase

Question 19

What does a high CK increase the risk of?

Answer 19

Kidney damage

Question 20

Why might you do an ECG in someone presenting with rhabdomyolysis?

Answer 20

Due to hyperkalaemia

Question 21

What is the main management of rhabdomyolysis?

Answer 21

IV fluids

Question 22

What is the purpose of IV fluids?

Answer 22

Rehydrate the patient and encourage filtration of the breakdown products.

Question 23

What else might you give to a patient with rhabdomyolysis?

Answer 23

IV sodium bicarbonate

Question 24

What is the purpose of IV sodium bicarbonate?

Answer 24

Urinary alkalinization- reduce the toxicity of the myoglobin on the kidneys

Question 25

How would the bloods of someone with rhabdomyolysis present?

Answer 25

• ↑ urea and creatinine (AKI)
• ↑ creatine kinase (CK)
• myoglobinuria — tea- or cola-coloured urine
• hypocalcaemia
• elevated phosphates (released from myocytes)
• hyperkalaemia
• metabolic acidosis

Question 26

What can rhabdomyolysis cause?

Answer 26

AKI due to acute tubular necrosis