Potassium Levels in Rhabdomyolysis

Pathophysiology of Hyperkalemia in Rhabdomyolysis

• Rhabdomyolysis involves breakdown of skeletal muscle cells, leading to release of intracellular contents including potassium into the circulation 1
• Approximately 98% of the body's potassium is contained within cells, with only 2% in the extracellular compartment, making even small shifts potentially dangerous 2
• When muscle cells are damaged, the potassium contained within them leaks into the bloodstream, causing hyperkalemia 3
• The risk of hyperkalemia is further increased when rhabdomyolysis leads to acute kidney injury, as the kidneys lose their ability to excrete excess potassium 2

Clinical Significance of Hyperkalemia in Rhabdomyolysis

• Hyperkalemia severe enough to produce cardiac arrest can occur in severe cases of rhabdomyolysis 4
• Elevated potassium levels can produce cardiac irregularities including arrhythmias, ventricular tachycardia, fibrillation, or cardiac arrest 5
• Neuromuscular effects of hyperkalemia may include muscle cramps and paresthesia 5

Monitoring and Detection

• Close monitoring of serum potassium is advised to prevent subsequent severe dysrhythmias, especially in patients with combined trauma 6
• Plasma potassium measurement should be part of a repeated bio-assessment in patients with post-traumatic rhabdomyolysis 7, 8

Risk Factors for More Severe Hyperkalemia

• Acute kidney injury/renal failure complicating rhabdomyolysis 2
• Delayed treatment of rhabdomyolysis 8
• Pre-existing conditions that impair potassium excretion 2

Management Implications

• Maintaining urine pH at 6.5 may help prevent complications 8