Whilst the SIGN Guidelines state that the use of prophylactic antibiotics in surgery unequivocally reduces major morbidity, reduces hospital costs and is likely to decrease overall consumption of antibiotics they state the chosen antibiotics must reflect local, disease-specific information about the common pathogens and their antimicrobial susceptibility. Growing healthcare concern regarding the rates of Clostridium Difficile (C. Diff) within the hospital setting have led to rationalised and better streamlined prescribing practice within the NHS. In NHS Lanarkshire this led to revised guidelines for prophylactic antibiotic use in Orthopaedics in 2010. Routine use of 3. rd. generation Cephalosporin has been replaced by Flucloxacillin 1g and Gentamicin 1mg/kg. Anecdotally the surgeons within our department were concerned that they were recognising more post-operative renal impairment than before 2010. Our study took 902 consecutive cases treated surgically with either Total Hip Replacement, Total Knee Replacement, Dynamic Hip Screw for fracture and Hemiarthroplasty for fracture since the introduction of the new antibiotic policy. We compared this with a similar number of cases treated with the same operations pre-2010. We looked at the pre admission Urea & Electrolystes compared with immediate post-operative results and applied the definition of Acute Kidney Injury (AKI) as defined by the Acute Kidney Injury Network. A. A rapid time course (less than 48 hours) and B. Reduction of kidney function either as an absolute increase in serum creatinine of ≥26.4μmol/l (≥0.3 mg/dl) or a percentage increase in serum creatinine of ≥50%. Based on this definition we found an increased rate of AKI of 13.7% after the introduction of the use of Gentamicin from 9.8% before its routine use. We wish to highlight that the routine widespread use of Gentamicin may be increasing the rate of acute renal dysfunction seen in Orthopaedic patients undergoing major surgery

Prophylactic antibiotics administered prior to joint arthroplasty have become standard practice. Due to concern over the risk that 2nd generation cephalosporins posed to the elderly, as regards clostridium difficile associated infections the antimicrobial management team in our unit changed the protocol for prophylactic antibiotics. As of 1st September 2009, flucloxacillin and gentamicin were preferred over cefuroxime as the first choice of prophylactic antibiotic. However, it was noted that postoperatively patients were experiencing a decrease in renal function. One hundred patients who underwent a total hip replacement following the policy change were randomly selected from the departmental joint arthroplasty database. This group was age and sex matched to 100 patients undergoing their surgery prior to the change. Data was collected on renal function, length of stay, antibiotic and age. Any change in renal function was categorised using the RIFLE criteria. Exclusion secondary to variations from protocol or treatment for femoral neck fractures resulted in a total number of 156 patients with 78 in each arm. The average age for both groups was 64 years. Non-parametric analysis of preoperative and postoperative serum creatinine concentrations and Glomerular Filtration Rate (GFR) demonstrated a significant difference between the two groups, showing that GFR decreased (p=0.041) and serum creatinine concentration increased (p=0.037) in the cohort receiving gentamicin. Classing the impaired renal function as: risk, injury or failure (RIFLE criteria) demonstrated a statistically significant difference for any criterion positive (p=0.016) but no significant difference for the specific RIFLE groups (p=0.068). Acknowledging the small numbers and potential confounders for renal impairment, this study was able to show a difference in renal function for patients receiving gentamicin over cefuroxime as prophylaxis for joint arthroplasty