Original Research
Saturday, October 12, 2024
11:30 AM–01:00 PM
Abstract
Introduction:
The impact of extended prophylactic oral antibiotics after total joint arthroplasty (TJA) on postoperative antimicrobial resistance is not well quantified.
Research Question or Hypothesis:
Do TJA patients prescribed =7 days of postoperative oral antibiotic prophylaxis demonstrate greater antimicrobial resistance on subsequent microbiologic cultures than patients prescribed =1 day of perioperative antibiotic prophylaxis?
Study Design:
Retrospective cohort study
Methods:
Adult elective TJA patients at our center between 7/1/15-12/31/21 were screened for inclusion. We excluded patients on antecedent antimicrobial therapy, those with off-protocol antibiotic exposure, prolonged hospital stays, and those prescribed 1-6 days of oral prophylactic antibiotic (to ensure adequate group separation). The primary outcome was the rate of speciated microorganism growth in culture with resistance to the prophylactic oral antibiotic, compared between cephalexin vs. no oral antibiotic and between doxycycline vs. no oral antibiotic groups. Speciated microorganisms, resistance patterns, and antibiotic-related harms were also assessed. Chi square tests were used for categorical variables and Mann-Whitney U/non-parametric ANOVA for continuous data due to non-normality (SAS, v9.4). Power analysis determined 1398 total patients were required to detect a 15% increase in resistance with 80% power at alpha=0.05.
Results:
Study criteria yielded 3676 total patients, with 804 having microbiologic culture data available for assessment during a median follow-up timeframe of 67 months. The rate of cephalexin-resistant microbial growth was similar between patients prescribed cephalexin vs. no oral antibiotic (54.3% vs. 54.9%, p=0.867). Doxycycline resistance was non-significantly greater in the doxycycline group vs. the no oral antibiotic group (93.8% vs. 75.3%, p=0.089), though the subset of intrinsically doxycycline-resistant organisms were significantly more common (93.8% vs. 70.6%, p=0.044). C. difficile was significantly more common in the doxycycline group vs. the cephalexin group vs. the no antibiotic group (12.5% vs. 0% vs. 1.7%, p=0.004).
Conclusion:
This limited study detected potential antimicrobial resistance and harm associated with extended prophylactic oral antibiotics after TJA that warrant further investigation.
Presenting Author
Sara Hyland PharmD, BCCCPGrant Medical Center (OhioHealth)
Authors
Lindsey Clemmons BS
OhioHealth Grant Medical Center
Craig Fada BS
Marian School of Osteopathic Medicine
Robert Fada MD
Grant Medical Center (OhioHealth)
Brian Kramer PharmD, BCCCP
Grant Medical Center (OhioHealth)
Rodney Kusumi MD
Grant Medical Center (OhioHealth)
Lauren Lopez PharmD, MPH, BCPS, BCIDP
Grant Medical Center