115. SINGLE DOSE ANTIBIOTIC PROPHYLAXIS FOR LOWER LIMB ARTHROPLASTY

Abstract

Purpose: To assess the infection rate following Lower Limb Arthroplasty using single dose gentamicin antibiotic prophylaxis compared to a traditional three doses of cephalosporin.

Method: All patients undergoing Total Hip and Knee replacements over six months (October 2007 to March 2008) at three participating hospitals were prospectively followed to assess perioperative infection rates using Surgical Site Surveillance(SSI) criteria. All patients received single dose antibiotic prophylaxis using intravenous Gentamicin 4.5mg/kg. This was compared with previous data collected over a 6 month period (Jan to Mar 2007 and Oct to Dec 2005) from the same hospitals using 3 doses of Cefuroxime 750mg. Return to theatre data was collected independently after introduction of gentamicin to compare with previous data. The change in creatinine level postoperatively was also measured in a selected group of patients.

Results: Four hundred and eight patients underwent Total Hip Replacements (THR) and 458 patients Total Knee Replacements (TKR) during the study period. This was compared with 414 and 421 patients who underwent THRs and TKRs respectively during a previous six month period. SSI was detected in 9 THRs(2.2%) and 2 TKRs(0.44%) in the study group as compared to 13 THRs(3.1%) and 12 TKRs(2.9%) in the control group. The infection rates in THRs were not significantly different between the 2 groups(p value−0.52) but were significantly reduced in the study group for TKRs(p value−0.005). The rate of Clostridium difficile infection was reduced within the hospital with the use of gentamicin, although other measures to reduce its incidence were also introduced. The return to theatre was 1.64%(23/1402) after introduction of Gentamicin as compared with 1.05%(21/2005) [p value−0.092] before this. This was a cause for concern although not significant. The day1 postoperative creatinine level increased by more than 30 units in 6% of patients on Gentamicin.

Conclusion: This study shows that the use of single dose prophylaxis using Gentamicin is effective for Lower Limb Arthroplasty. However, be wary of increased rate of return to theatre and the rise in creatinine level following use of gentamicin. Further period of evaluation and study is needed before it is recommended for routine use in present or modified form.