The incidence, risk factors, and outcomes of acute kidney injury after minor lower-limb amputations.

Background and aims: Minor lower-limb amputations are limb and potentially life-saving procedures. However, they are associated with serious adverse events, including acute kidney injury (AKI).

Materials and methods: We conducted a single-center retrospective study to determine the incidence of AKI after these procedures, identify risk factors, and assess impact on patient survival.

Results: We included 201 patients. AKI occurred in 18.9% using AKIN criteria, and 24.9% using KDIGO criteria. Only 1 patient required temporary dialysis. Patients with AKI were older (73.0 ± 10.4 vs. 68.5 ± 11.8 years, p = 0.033), had a higher incidence of chronic kidney disease (CKD); estimated glomerular filtration rate (eGFR) < 45 mL/min/1.73m² (39.5 vs. 14.7%, p = 0.001), and/or chronic obstructive pulmonary disease (COPD) (28.9 vs. 13.5% p = 0.028), and higher use of diuretics (68.4 vs. 49.1%, p = 0.049), fluoroquinolones (71.1 vs. 52.8% p = 0.047), and/or carbapenems (10.5 vs. 2.5%, p = 0.043) compared to patients without AKI. eGFR < 45 mL/min/1.73m² (OR: 3.24, CI: 1.40 - 7.52, p = 0.006), use of fluoroquinolones (OR: 3.19, CI: 1.30 - 7.82, p = 0.012), and day-1 C-reactive protein (CRP) (OR: 1.01, CI: 1.00 - 1.01, p = 0.009) were established as independent risk factors for AKI. Cumulative survival was not significantly lower in patients with AKI (log rank: 0.02, p = 0.88).

Conclusion: AKI is a potential complication following minor lower-limb amputations. Age, COPD, diuretics, fluoroquinolones, and carbapenems were associated with increased incidence of AKI. An eGFR < 45 mL/min/1.73m², day-1 C-reactive protein, and fluoroquinolone use were identified as independent risk factors for AKI.