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McMahon score for rhabdomyolysis

Predicts death or AKI requiring renal replacement in rhabdomyolysis.

McMahon score for rhabdomyolysis
Age
Female sex
Initial creatinine
Initial calcium <7.5 mg/dL
Initial CPK >40,000 U/L
Cause NOT seizure, syncope, exercise, statin, or myositis
Initial phosphate
Initial bicarbonate <19 mEq/L
Result0.0 points

Score <6 identifies patients at low risk (composite death or renal-replacement-requiring AKI <3%); a score >=6 marks higher risk and should prompt renal-protective measures.

Risk category
Low risk

When to use

  • Estimating, at presentation, the risk of death or dialysis-requiring AKI in rhabdomyolysis to guide disposition.

Formula

Weighted sum of age, female sex (1), creatinine, calcium <7.5 (2), CPK >40,000 (2), non-benign cause (3), phosphate, and bicarbonate <19 (2). Score <6 = low risk; >=6 = high risk.

References

  1. McMahon GM, et al. JAMA Intern Med. 2013;173(19):1821-8.