Serum Myoglobin Levels and Rhabdomyolysis Diagnosis

Diagnostic Criteria and Thresholds

CPK levels above five times normal (approximately 1000 IU/L) are considered diagnostic of rhabdomyolysis, and myoglobin has an earlier peak plasma concentration than CPK, making it more sensitive for early detection, according to the Anaesthesia guideline society 1
In patients with crush syndrome, CPK levels above 75,000 IU/L correlate with a high incidence (>80%) of acute kidney injury, as recommended by the Anaesthesia guideline society 1

For patients with myoglobin >600 ng/mL, monitoring should include urine output hourly and maintaining urine pH at 6.5, as well as monitoring serum potassium for hyperkalaemia and renal function via plasma creatinine, according to the Anaesthesia guideline society 1
Aggressive fluid resuscitation is crucial, with volumes greater than 6L required for severe rhabdomyolysis (CPK >15,000 IU/L), and 3-6L per day sufficient for moderate rhabdomyolysis, as recommended by the Anaesthesia guideline society 2
Early initiation of volume resuscitation is associated with better outcomes in preventing acute kidney injury, according to the Anaesthesia guideline society 2