310. Peri-operative Antibiotic Prophylaxis in Era of Multi-drug Bacterial Resistance
Session: Poster Abstract Session: Assessing and Reducing Infection Risk
Friday, October 21, 2011
Room: Poster Hall B1

Background: Limited data exist for guiding peri-operative antibiotic prophylaxis in the era of emerging antibiotic resistance.

Methods: We retrospectively reviewed all arthroplasty and spinal fusion surgeries performed at a 190 bed orthopedic specialty hospital from January 1, 2008 to July 31, 2010, complicated by surgical site infections (SSIs), as defined by CDC NHSN criteria. Cases were identified by review of daily microbiology culture reports, review of readmissions, and daily Infection Control rounds. Infections were stratified by NHSN case definition, surgery type, and anatomical location.

Results: Sixty-nine arthroplasty SSIs (31 Hip, 37 Knee, and 1 Shoulder) and 80 spine SSIs (10 Cervical, 27 Dorsal, and 43 Lumbar) were identified.  Nineteen percent of arthroplasty SSIs were superficial and 81% were deep, whereas among spinal SSIs, 25% were superficial and 75% were deep.

Among arthroplasty SSIs, 55 (80%) cases were infected with Gram positive bacteria and 21 (30%) yielded Gram negative bacteria (7 cases grew at least 1 of each). Of 68 Gram positive isolates, 42 (62%) were staph species. Seven (33%) S. aureus isolates were MRSA (86% deep infections), while 16 (76%) coagulase negative staph isolates were MRSE (81% deep infections).  Among 27 Gram negative isolates, 12 (44%) were resistant to cefazolin (75% deep infections) and 2 (7%) were resistant to gentamicin (50% deep infections).

Among spine SSIs, 64 (80%) cases were infected with Gram positive bacteria and 20 (25%) yielded Gram negative bacteria (4 cases grew at least 1 of each).  Of 75 Gram positive isolates, 55 (73%) were staph species. Eight (26%) S. aureus isolates were MRSA (88% deep infections), while 16 (67%) coagulase negative staph isolates were MRSE (75% deep infections).  Among 21 Gram negative isolates, 12 (57%) were resistant to cefazolin (83% deep infections) and 2 (10%) were resistant to gentamicin (100% deep infections).

Conclusion: Review of antimicrobial susceptibilities of pathogens causing SSIs at our institution indicates peri-operative cefazolin may be inadequate for SSI prevention.  In the setting of these bacterial resistance trends, peri-operative vancomycin and gentamicin may provide enhanced prophylaxis for arthroplasty and spine SSIs at our institution.


Subject Category: N. Hospital-acquired and surgical infections, infection control, and health outcomes including general public health and health services research

Thomas D. Norton, MD, Infectious Diseases, NYU Langone Medical Center, New York, NY, Faith Skeete, RN, Infection Prevention and Control Department, New York University Langone Medical Center, New York, NY, Michael S. Phillips, MD, Infection Control and Prevention, New York University Langone Medical Center, New York, NY, Joseph Bosco III, MD, Orthopedic Surgery, New York University Hospital for Joint Diseases, New York, NY and Sapna A. Mehta, MD, New York University School of Medicine, New York, NY

Disclosures:

T. D. Norton, None

F. Skeete, None

M. S. Phillips, None

J. Bosco III, None

S. A. Mehta, None

Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.