title: Effectiveness of local vancomycin powder to decrease surgical site infections: a meta-analysis.
abstract: BACKGROUND
  Some surgeons use systemic vancomycin to prevent surgical site infections (SSIs), but patients who do not carry methicillin-resistant Staphylococcus aureus have an increased risk of SSIs when given vancomycin alone for intravenous prophylaxis. Applying vancomycin powder to the wound before closure could increase the local tissue vancomycin level without significant systemic levels. However, the effectiveness of local vancomycin powder application for preventing SSIs has not been established.
  
  
  OBJECTIVE
  Our objective was to systematically review and evaluate studies on the effectiveness of local vancomycin powder for decreasing SSIs.
  
  
  METHODS
  Meta-analysis.
  
  
  METHODS
  We included observational studies, quasi-experimental studies, and randomized controlled trials of patients undergoing surgical procedures that involved vancomycin powder application to surgical wounds, reported SSI rates, and had a comparison group that did not use local vancomycin powder.
  
  
  METHODS
  The primary outcome was postoperative SSIs. The secondary outcomes included deep incisional SSIs and S. aureus SSIs.
  
  
  METHODS
  We performed systematic literature searches in PubMed, the Cochrane Database of Systematic Reviews, the Database of Abstracts of Reviews of Effects, the Cochrane Central Register of Controlled Trials via Wiley, Scopus (including EMBASE abstracts), Web of Science, ClinicalTrials.gov, BMC Proceedings, ProQuest Dissertation, and Thesis in Health and Medicine, and conference abstracts from IDWeek, the Interscience Conference on Antimicrobial Agents and Chemotherapy, the Society for Healthcare Epidemiology of America, and the American Academy of Orthopedic Surgeons annual meetings, and also the Scoliosis Research Society Annual Meeting and Course. We ran the searches from inception on May 9, 2013 with no limits on date or language. After reviewing 373 titles or abstracts and 22 articles in detail, we included 10 independent studies and used a random-effects model when pooling risk estimates to assess the effectiveness of local vancomycin powder application for preventing SSIs, the outcome of interest. We used the I²-index, Q-statistic, and corresponding p value to assess the heterogeneity of the risk estimates, and funnel plots to assess publication bias.
  
  
  RESULTS
  We included seven quasi-experimental studies, two cohort studies, and one randomized controlled trial, encompassing 5,888 surgical patients. The pooled effects showed that applying local vancomycin powder was significantly protective against SSIs (pooled odds ratio [pOR] 0.19; 95% confidence interval [CI] 0.09-0.38), deep incisional SSIs (pOR 0.23; 95% CI 0.09-0.57), and SSIs caused by S. aureus (pOR 0.22; 95% CI 0.08-0.58). However, significant heterogeneity was present for studies evaluating all SSIs or deep incisional SSIs. When we pooled the risk estimates from the eight studies that assessed patients undergoing spinal operations, vancomycin powder remained significantly protective against SSIs (pOR 0.16; 95% CI 0.09-0.30), deep incisional SSIs (pOR 0.18; 95% CI 0.09-0.36), and SSIs caused by S. aureus (pOR 0.11; 95% CI 0.03-0.36). The pooled ORs from studies of spinal operations were lower than those for all studies and the estimates from spinal operation studies were homogeneous. However, there was evidence of publication bias.
  
  
  CONCLUSIONS
  Local administration of vancomycin powder appears to protect against SSIs, deep incisional SSIs, and S. aureus SSIs after spinal operations. Large, high-quality studies should be performed to evaluate this intervention before it is used routinely.
authors.affiliation: Department of Internal Medicine, The University of Iowa Carver College of Medicine, 200 Hawkins Drive, Iowa City, IA 52242, USA. Electronic address: hsiu-yin-chiang@uiowa.edu.
authors.forename: Hsiu-Yin
authors.initials: HY
authors.lastname: Chiang
authors.affiliation: Department of Internal Medicine, The University of Iowa Carver College of Medicine, 200 Hawkins Drive, Iowa City, IA 52242, USA; Department of Epidemiology, The University of Iowa College of Public Health, College of Public Health Building (CPHB), 105 River St, Iowa City, IA 55242, USA.
authors.forename: Loreen A
authors.initials: LA
authors.lastname: Herwaldt
authors.affiliation: Hardin Library for the Health Sciences, The University of Iowa, 100 Hardin Library for the Health Sciences (HLHS), Iowa City, IA 55242, USA.
authors.forename: Amy E
authors.initials: AE
authors.lastname: Blevins
authors.affiliation: Department of Internal Medicine, The University of Iowa Carver College of Medicine, 200 Hawkins Drive, Iowa City, IA 52242, USA.
authors.forename: Edward
authors.initials: E
authors.lastname: Cho
authors.affiliation: Department of Internal Medicine, The University of Iowa Carver College of Medicine, 200 Hawkins Drive, Iowa City, IA 52242, USA; Department of Epidemiology, The University of Iowa College of Public Health, College of Public Health Building (CPHB), 105 River St, Iowa City, IA 55242, USA; Iowa City Veterans Affairs Health Care System, 601 Highway 6 West, Iowa City, IA 52246, USA.
authors.forename: Marin L
authors.initials: ML
authors.lastname: Schweizer
mesh_terms: D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D006801:Humans; D015994:Incidence; D017063:Outcome Assessment, Health Care; D011208:Powders; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control*; D013211:Staphylococcus aureus; D013530:Surgical Wound Infection / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control*; D016896:Treatment Outcome; D014640:Vancomycin / Q000008:administration & dosage / Q000627:therapeutic use*
chemical_list: D000890:Anti-Infective Agents; D011208:Powders; D014640:Vancomycin
keywords: Meta-analysis; Prophylaxis; Spinal operation; Staphylococcus aureus; Surgical site infections; Vancomycin powder