Hypokalaemic rhabdomyolysis

Area of Science:

• Internal Medicine
• Nephrology
• Neurology

Background:

• Hypokalaemia (low serum potassium) is an uncommon cause of rhabdomyolysis (muscle breakdown).
• The link between hypokalaemia and rhabdomyolysis may be missed if serum potassium levels normalize due to intracellular shifts before patient presentation.

Observation:

• A patient presented with severe, non-traumatic rhabdomyolysis and profound hypokalaemia (serum potassium 1.4 mmol/L).
• Other notable lab findings included low magnesium (0.40 mmol/L), phosphate (1.40 mmol/L), and adjusted calcium (1.87 mmol/L), with markedly elevated creatine kinase (6421 U/L).
• The patient initially denied, but later admitted to, alcohol misuse preceding withdrawal three days prior to presentation.

Findings:

• The patient's hypokalaemia was refractory to initial potassium chloride treatment, potentially due to concurrent magnesium deficiency.
• Alcohol misuse is a known risk factor for hypokalaemia, and abrupt alcohol withdrawal can worsen both hypokalaemia and hypomagnesaemia.
• Alcohol toxicity can cause myopathy, and paradoxically, abrupt alcohol withdrawal may increase the risk of rhabdomyolysis.

Implications:

• This case highlights the importance of considering hypokalaemia in unexplained rhabdomyolysis, even with normal serum potassium levels on presentation.
• Coexisting electrolyte abnormalities, such as magnesium deficiency, can complicate the management of hypokalaemia-induced rhabdomyolysis.
• Abrupt alcohol withdrawal is a critical factor that can precipitate severe hypokalaemia and rhabdomyolysis in susceptible individuals.