Use of Myoglobin as a Marker and Predictor in Myoglobinuric Acute Kidney Injury

Serum creatine kinase ( CK ) is routinely used as a marker in the assessment of rhabdomyolysis and acute myoglobinuric kidney injury ( Mb ‐ AKI ), while the use of myoglobin is much less explored in this respect. We retrospectively analyzed the incidence of Mb ‐ AKI (creatinine [ Cr]  > 200 μmol/L) and the need for hemodialysis ( HD ) in 484 patients (70.5% males) with suspected rhabdomyolysis, grouped according to peak serum myoglobin (A: 1–5 mg/L, B: 5–15 mg/L, C: >15 mg/L). The median peak myoglobin was 7163 μg/L. Both peak Cr and peak CK were significantly higher in group C. The incidence of Mb ‐ AKI was 24.6% in group A, 38.6% in group B ( P  < 0.01 vs. group A), and significantly higher (64.9%) in group C ( P  < 0.001 vs. groups A and B). Fifty‐one patients (10.5%) needed HD , the proportion increasing from 6.7% in group A, and 12.3% in group B ( NS ), to 28.1% in group C ( P  < 0.001 vs. group A, P 0.01 vs. group B), and reaching 36.8% with myoglobin >20 mg/L. Creatine kinase correlated with the severity of rhabdomyolysis, but less so with Mb ‐ AKI . The peak Cr levels were not significantly different between patients divided by CK 60 μkat/L, or grouped into CK tertiles or quartiles. A significant proportion of patients with rhabdomyolysis experienced Mb ‐ AKI , whose frequency increased in parallel with myoglobin levels. Myoglobin levels above 15 mg/L were most significantly related to the development of AKI and the need for HD. Blood myoglobin could serve as a valuable early predictor and marker of rhabdomyolysis and Mb ‐ AKI .