Urine pH is associated with the development of acute kidney injury in crush syndrome.

Acute kidney injury (AKI) is a critical complication in crush syndrome (CS). This retrospective study, performed from May 1st, 2019, to April 30th, 2024, analyzed 231 CS patients to identify AKI predictors. We compared urine pH, creatine kinase (CK), and serum creatinine on days 1, 3, 5, and 7 between AKI and non-AKI groups. AKI patients were older and had more severe trauma (p < 0.05). Urine pH progressively declined in the AKI group, remaining lower than non-AKI (except admission day), while CK and creatinine rose continuously (p < 0.05). Multivariable analysis identified urine pH on day 5 [odds ratio (OR) 0.301, p = 0.001], CK on day 1 (OR 1.000, p = 0.023) and Injury Severe Score (ISS) scores (OR 1.082, p = 0.008) as independent AKI predictors. The area under the ROC curve (AUC) for urine pH (day 5), CK (day 1) and ISS scores were 0.975, 0.838 and 0.761, respectively. The current study showed that urine pH persistently decreases in CS-related AKI, whereas CK increases. Urine pH on day 5, CK on day 1 and ISS scores independently predict AKI, highlighting potential ability of urine pH for early intervention and risk assessment in CS patients.