A retrospective study of acute kidney injury in hip arthroplasty patients receiving gentamicin and dicloxacillin

Background and purpose - Acute kidney injury is a known complication 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 gentamicin 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/gentamicin 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.