From the Research
Creatinine kinase (CK) levels in rhabdomyolysis should be monitored daily until they begin to decline, and then can be checked every 1-2 days until they normalize or stabilize at a new baseline. Initially, CK levels should be measured at presentation to establish a baseline, then repeated within 12-24 hours to determine if levels are rising or falling. Once CK levels start decreasing, which typically occurs 3-5 days after the initial insult, the frequency can be reduced. The monitoring should continue until CK levels fall below 5,000 U/L or decrease by approximately 50% from peak values, as this generally indicates resolving muscle injury 1. More frequent monitoring may be necessary for patients with severe rhabdomyolysis (CK >50,000 U/L), compromised renal function, or electrolyte abnormalities. This monitoring schedule helps clinicians assess the severity of muscle damage, guide fluid resuscitation therapy, and detect potential complications such as acute kidney injury. Remember that CK monitoring should always be interpreted alongside clinical symptoms, urine output, renal function tests, and electrolyte levels for comprehensive management of rhabdomyolysis. Some studies suggest that the predictive power of CK level on acute kidney injury is limited, especially regarding long-term renal function 2. However, close follow-up examinations of renal function after haemodialysis are mandatory for patients with rhabdomyolysis. The goal of CK monitoring is to prioritize morbidity, mortality, and quality of life as the outcome, and to guide treatment decisions based on the most recent and highest quality evidence 3.
Some key points to consider when monitoring CK levels in rhabdomyolysis include:
- Measuring CK levels at presentation to establish a baseline
- Repeating CK levels within 12-24 hours to determine if levels are rising or falling
- Reducing the frequency of monitoring once CK levels start decreasing
- Continuing monitoring until CK levels fall below 5,000 U/L or decrease by approximately 50% from peak values
- Interpreting CK monitoring results alongside clinical symptoms, urine output, renal function tests, and electrolyte levels.
It is also important to note that the use of CK levels to predict long-term renal function remains controversial, and that close follow-up examinations of renal function after haemodialysis are mandatory for patients with rhabdomyolysis 2. Overall, the monitoring of CK levels in rhabdomyolysis should be guided by the most recent and highest quality evidence, and should prioritize morbidity, mortality, and quality of life as the outcome.