From the Guidelines
Rhabdomyolysis can cause a normal anion gap metabolic acidosis, as evidenced by anecdotal reports of proximal tubular injury with Fanconi syndrome, which manifests as hypokalaemia, hypophosphataemia, normal anion gap metabolic acidosis, and hypovolaemia from salt wasting 1. This occurs because during rhabdomyolysis, damaged muscle cells release their contents into the bloodstream, including various substances that can affect kidney function and acid-base balance. The release of myoglobin from damaged muscle tissue can cause intraluminal kidney tubular obstruction, resulting in reduced glomerular filtration rate and potentially leading to acute kidney injury, which is correlated with increased mortality 1. Key features of rhabdomyolysis include muscle pain, weakness, dark urine, and elevated creatine kinase levels. Treatment focuses on aggressive intravenous fluid resuscitation with normal saline, monitoring urine output, and addressing the underlying cause of muscle breakdown. In some cases, the measurement of plasma myoglobin and potassium levels, as well as kidney function tests, can help identify the risk of acute kidney injury and guide management decisions 1. It is essential to note that while rhabdomyolysis is often associated with normal anion gap metabolic acidosis, the condition can present with various metabolic derangements, and clinical vigilance is crucial for early detection and diagnosis. The use of sodium bicarbonate in the treatment of significant acidosis remains controversial and should be considered on a case-by-case basis. Overall, the management of rhabdomyolysis requires a comprehensive approach that addresses the underlying cause, prevents further kidney injury, and mitigates the risk of morbidity and mortality.
From the Research
Rhabdomyolysis and Anion Gap Metabolic Acidosis
- Rhabdomyolysis is characterized by skeletal muscle necrosis, resulting in the release of toxic muscle cell components into circulation, including electrolytes, myoglobin, and other sarcoplasmic proteins 2.
- This condition can lead to metabolic acidosis, as mentioned in several studies 2, 3, 4.
- Metabolic acidosis with an extremely elevated anion gap has been reported in a patient with rhabdomyolysis, renal failure, and hyperphosphatemia 5.
- The development of anion gap metabolic acidosis in rhabdomyolysis can be attributed to the accumulation of organic acids, reduced kidney function, and other factors 6.
- The management of rhabdomyolysis-induced metabolic acidosis may involve the use of saline and sodium bicarbonate, especially in patients with metabolic acidosis 2.
Key Findings
- Rhabdomyolysis can cause metabolic acidosis, which may be associated with an elevated anion gap 5, 4.
- The condition can lead to acute kidney injury, which may further contribute to the development of metabolic acidosis 2, 3.
- Early detection and treatment of rhabdomyolysis are crucial to prevent complications, including metabolic acidosis and acute kidney injury 4.