Assessment of the effectiveness of weight-adjusted antibiotic administration,for reduced duration,in surgical prophylaxis of primary hip and knee arthroplasty

BACKGROUND Prophylactic antibiotics have significantly led to a reduction in the risk of postoperative surgical site infections(SSI)in orthopaedic surgery.The aim of using antibiotics for this purpose is to achieve serum and tissue drug levels that exceed,for the duration of the operation,the minimum inhibitory concentration of the likely organisms that are encountered.Prophylactic antibiotics reduce the rate of SSIs in lower limb arthroplasty from between 4%and 8%to between 1%and 3%.Controversy,however,still surrounds the optimal frequency and dosing of antibiotic administration.AIM To evaluate the impact of introduction of a weight-adjusted antibiotic prophylaxis regime,combined with a reduction in the duration of administration of post-operative antibiotics on SSI incidence during the 2 years following primary elective total hip and knee arthroplasty METHODS Following ethical approval,patients undergoing primary total hip arthroplasty(THA)/total knee arthroplasty(TKA)with the old regime(OR)of a preoperative dose[cefazolin 2 g intravenously(IV)],and two subsequent doses(2 h and 8 h),were compared to those after a change to a new regime(NR)of a weight-adjusted preoperative dose(cefazolin 2 g IV for patients<120 kg;cefazolin 3g IV for patients>120 kg)and a post-operative dose at 2 h.The primary outcome in both groups was SSI rates during the 2 years post-operatively.RESULTS A total of n=1273 operations(THA n=534,TKA n=739)were performed in n=1264 patients.There was no statistically significant difference in the rate of deep(OR 0.74%(5/675)vs NR 0.50%(3/598);fishers exact test P=0.72),nor superficial SSIs(OR 2.07%(14/675)vs NR 1.50%(9/598);chi-squared test P=0.44)at 2 years postoperatively.With propensity score weighting and an interrupted time series analysis,there was also no difference in SSI rates between both groups[RR 0.88(95%CI 0.61 to 1.30)P=0.46].CONCLUSION A weight-adjusted regime,with a reduction in number of post-operative doses had no adverse impact on SSI incidence in this population.

Impact of extended-infusion piperacillin-tazobactam in a Canadian community hospital

Background:Studies have demonstrated improved clinical outcomes with extended infusion(EI)piperacillin/tazobactam(TZP)compared to standard infusion(SI).However,there is less evidence on its benefits in noncritically-ill patients.Hospital-wide EI TZP was implemented at our site on February 21,2012.Our objectives were to compare clinical,safety and economic outcomes between EI and SI TZP.Methods:A retrospective cohort study of all adult patients who received EI TZP(3.375 g IV q8h infused over 4 hours and SI TZP for≥48 hours during 3 years pre-and postimplementation was conducted.The primary study outcome was 14-day mortality while secondary outcomes included length of hospital stay(LOS),nursing plus pharmacy cost,occurrence of Clostridioides difficile infection,readmission within 30 days and change in Pseudomonas aeruginosa minimum inhibitory concentration(MIC)distribution for TZP.The primary outcome and binary secondary outcomes were analyzed using a logistic regression model.LOS was examined using time to event analysis.Cost was examined using linear regression modelling.Results:Overall,2034 patients received EI TZP and 1364 patients received SI TZP.EI TZP was associated with lower odds of mortality(OR 0.76,95%CI 0.63-0.91),lower odds of C.difficile infection(OR 0.59,95%CI 0.41-0.84)and 8%lower cost(estimate 0.92,95%CI 0.87-0.98)compared to SI TZP.Conclusions:Hospital-wide implementation of EI TZP was associated with lower odds of 14-day mortality and incidence of C.difficile infection with cost savings at our institution.