Calcular

McMahon Score for Rhabdomyolysis

The McMahon Score predicts the risk of acute kidney injury, need for renal replacement therapy, or in‑hospital mortality in patients with rhabdomyolysis.

Age, years

≤ 50051-70+1.571-80+2.5> 80+3

Sex

Male0

Female+1

Initial creatinine

< 1.4 mg/dL (124 µmol/L)01.4 - 2.2 mg/dL (124-195 µmol/L)+1.5> 2.2 mg/dL (195 µmol/L)+3

Initial calcium < 7.5 mg/dL (1.88 mmol/L)

No0

Yes+2

Initial CPK > 40,000 U/L

No0

Yes+2

Rhabdo secondary to seizures, syncope, exercise, statins or myositis

Yes0

No+3

Initial phosphate

< 4.0 mg/dL (1.0 mmol/L)04.0 - 5.4 mg/dL (1.0 - 1.4 mmol/L)+1.5> 5.4 mg/dL (1.4 mmol/L)+3

Initial bicarbonate < 19 mEq/L

No0

Yes+2

Indicaciones de Uso

Used in adults with confirmed rhabdomyolysis at presentation to estimate risk of AKI requiring RRT or in‑hospital mortality, guiding fluid intensity, monitoring level, and early nephrology involvement. Developed/validated in large cohorts (n=2371; composite outcome 19%) with strong discrimination (C‑statistic 0.82–0.83) 1 [Level II evidence]. A cutoff ≥6 identifies high‑risk patients; scores <5 indicate very low short‑term risk.

Información y Precauciones

Stratify risk of AKI, RRT, or mortality using admission age, etiology, creatinine, CPK, phosphate, calcium, and bicarbonate, recognizing high-risk scores (≥6) signal markedly increased adverse outcomes (e.g., 61% risk at >10 in validation cohort) 1 [Level II evidence]. Use cautiously: performance varies by population (AUC ~0.72–0.83 across settings) 2 [Level II evidence], and external validations note reduced calibration in heterogeneous cohorts.