A retrospective study of acute kidney injury in hip arthro-plasty patients receiving gentamicin and dicloxacillin

Background and purpose — Acute kidney injury is a known com- plication of antibiotic use. Antibiotic prophylaxis is essential to prevent periprosthetic infections after total hip replacement. We experienced a rise in the incidence of acute kidney injury (AKI), and in an effort to solve this problem, we changed our antibiotic prophylaxis protocol. We investigated whether removing genta- micin from our antibiotic protocol would cause fewer and less severe cases of renal impairment. Patients and methods — We performed a retrospective study involving 136 cases of total hip replacement, with 66 patients receiving dicloxacillin and gentamicin and 70 patients receiving dicloxacillin alone. Results — We found less cases of AKI in the dicloxacillin group (p = 0.03): the mean creatine level in the dicloxacillin/gentami- cin group was 126 (25–422) μmol/L whereas it was 93 (39–278) μmol/L in the group that received dicloxacillin alone. We also found that cases were less severe in the dicloxacillin group than in the dicloxacillin/gentamicin group (p = 0.02). The relative risk of developing AKI was 3 times higher if dicloxacillin and gentamicin were both used (p = 0.02). Interpretation — After removing gentamicin, there were fewer and less severe cases of acute kidney injury