From the Guidelines
Rhabdomyolysis is typically associated with creatine kinase (CK) levels exceeding 5 times the upper limit of normal, which is generally above 1,000 U/L, as indicated by raising CPK levels above five times normal 1. When considering the relationship between CK levels and rhabdomyolysis, it's essential to note that:
- CK levels above 5,000 U/L are often considered diagnostic for rhabdomyolysis 1
- Severe cases of rhabdomyolysis can show CK levels above 10,000 U/L or even reaching 100,000 U/L 1
- The exact threshold for diagnosing rhabdomyolysis may vary between institutions and clinical contexts
- Elevated CK levels reflect significant muscle damage, with the release of muscle contents into the bloodstream 1 Some key points to consider in the management of suspected rhabdomyolysis include:
- Aggressive IV fluid administration to prevent kidney damage, regardless of the exact CK value
- Monitoring of renal function, electrolytes (particularly potassium), and acid-base status
- The severity of rhabdomyolysis and its complications, such as acute kidney injury, does not always correlate perfectly with CK levels 1
From the Research
Rhabdomyolysis and Creatine Kinase (CK) Levels
- Rhabdomyolysis is a syndrome caused by muscle breakdown, which can lead to elevated creatine kinase (CK) levels 2.
- CK levels in rhabdomyolysis can range from 10,000 to 200,000 or even higher, with higher levels indicating greater renal damage and associated complications 2.
- A study found that a patient with exceptionally massive rhabdomyolysis had CK levels of nearly 1 million, caused by combined etiologic factors and complicated with acute renal failure 2.
Correlation between CK Levels and Rhabdomyolysis
- A retrospective cohort study found that rhabdomyolysis developed in 24.8% of patients with a median peak CK level of 4,178 U/L, ranging from 208 U/L to 120,000 U/L 3.
- The study also found a weak but statistically significant correlation between peak CK levels and the development of acute kidney injury (AKI) 3.
- Another study found that elevated peak CK levels in injured war fighters were weakly associated with the development of AKI but were not predictive 3.
CK Levels in Different Studies
- A study on experimental rhabdomyolysis in rats found that CK levels were elevated in response to traumatic injury, with different resuscitation fluids having varying effects on tissue blood flow and oxidant injury 4.
- A review of the literature on elevated serum CK levels in psychiatric practice found that antipsychotic-induced rhabdomyolysis was a significant concern, with CK levels often elevated in patients with muscular symptoms 5.
- A retrospective cohort study on children with hyperCKemia found that an optimal CK threshold of 777 was identified, with weakness and family history of neuromuscular disorders associated with neuromuscular disorders 6.