From the Guidelines
Rhabdomyolysis is confirmed through elevated creatine kinase (CK) levels, with a CK level greater than 5 times the upper limit of normal (typically >1,000 U/L) being the most definitive diagnostic marker, as stated in the 2021 guidelines for the acute care of severe limb trauma patients 1. This diagnosis is supported by clinical findings and laboratory tests, including myoglobinuria, elevated serum creatinine, hyperkalemia, hypocalcemia, hyperphosphatemia, and metabolic acidosis.
Key Diagnostic Markers
- Elevated CK levels: a level greater than 5 times the upper limit of normal confirms the diagnosis
- Myoglobinuria: causes tea or cola-colored urine
- Elevated serum creatinine: indicates kidney damage
- Hyperkalemia: a life-threatening condition that requires immediate attention
- Hypocalcemia and hyperphosphatemia: electrolyte imbalances that can lead to serious complications
- Metabolic acidosis: a condition that can lead to organ failure if left untreated
Importance of Early Diagnosis
Early diagnosis of rhabdomyolysis is crucial, as it can lead to acute kidney injury, electrolyte abnormalities, and compartment syndrome if not promptly treated with aggressive intravenous fluid resuscitation to maintain adequate urine output and prevent kidney damage, as recommended in the 2021 guidelines for the acute care of severe limb trauma patients 1.
Recommended Diagnostic Approach
A repeated bio-assessment combining plasma myoglobin, plasma creatine phosphokinase (CPK), and kalaemia measurements, along with bladder catheterisation to monitor hourly urine output and urine pH, is probably recommended to detect acute kidney injury in patients suffering from post-traumatic acute rhabdomyolysis after limb traumatic injury 1.
From the Research
Diagnosis of Rhabdomyolysis
The diagnosis of rhabdomyolysis is confirmed by several factors, including:
- Elevated creatine kinase (CK) levels, which is a key marker for muscle damage 2, 3, 4
- Presence of myoglobinuria, which is the presence of myoglobin in the urine 3, 5, 6
- Clinical symptoms such as muscle pain, weakness, and dark urine 2, 3
- Electrolyte abnormalities and acute kidney injury (AKI) 3, 6
Biomarkers for Rhabdomyolysis
The following biomarkers are used to diagnose and monitor rhabdomyolysis:
- Creatine kinase (CK) levels, which are used to guide therapeutic interventions and predict the risk of AKI 2, 3, 4
- Myoglobin levels, which are used to predict the risk of AKI and guide therapy 5, 6
- Myoglobinuria, which is used to diagnose and monitor rhabdomyolysis 3, 5, 6
Definition of Rhabdomyolysis
A systematic review recommends the following definition for rhabdomyolysis: