Acute kidney injury following prophylactic flucloxacillin and gentamicin in primary hip and knee arthroplasty

BACKGROUND: Following concerns regarding the emergence of Clostridium difficile infection in 2010, we changed antibiotic prophylaxis in patients undergoing primary hip and knee arthroplasty from cefuroxime to flucloxacillin and single-dose (SD) gentamicin. A subsequent perceived increase in the incidence of post-operative acute kidney injury (AKI) led us to evaluate the AKI incidence between different prophylactic antibiotic regimes used at our centre. METHODS: We examined the incidence of AKI as defined by Kidney Disease: Improving Global Outcomes criteria in 1588 patients undergoing primary hip or knee arthroplasty from January 2010 to January 2015. Patients received the following prophylactic antibiotic regimes: 8 g flucloxacillin in four divided doses and SD gentamicin 1.5 mg/kg ideal body weight (IBW; maximum dose 120 mg; n = 400), 8 g flucloxacillin alone in four divided doses (n = 400), SD cefuroxime (n = 400), triple-dose (TD) cefuroxime (n = 188) and teicoplanin with SD gentamicin 1.5 mg/kg IBW (n = 200). RESULTS: The incidence of AKI was as follows: flucloxacillin and gentamicin (13%); flucloxacillin alone (8.5%); SD cefuroxime (2%); TD cefuroxime (0.5%); and teicoplanin and gentamicin (3%). Of the six patients who developed Stage 3 AKI, all were in the flucloxacillin and gentamicin group. The odds ratio for the development of AKI derived from a binary logistic regression model was highest in the flucloxacillin and gentamicin group [7.79 (95% confidence interval 3.54–17.14), P < 0.0001]. CONCLUSIONS: Our findings suggest that the use of prophylactic high-dose flucloxacillin and gentamicin should be used with caution in patients undergoing primary hip or knee arthroplasty without a clear advantage in reducing surgical site infections given the association with increased rates of AKI.