title: Can Drainage Using a Negative-Pressure Wound Therapy Device Replace Traditional Sample Collection Methods?
abstract: BACKGROUND
  In 2015 a new device for the collection of mediastinal fluid from patients with deep sternal wound infection (DSWI) in the presence of negative-pressure wound therapy (NPWT) became available. The present study was designed to evaluate whether changing sample collection devices increased micro-organism detection in patients undergoing NPWT.
  
  
  METHODS
  During 2013-2014, 207 samples were collected and cultured from NPWT patients (n = 23) to demonstrate the presence of DSWI using reticulated polyurethane sponge culture, a swab, and blood culture. In 2015, a new collection device was introduced for specimen collection. A total of 357 samples (n = 17) were collected using the ESwab(™) (Copan, Murrieta, CA) for deep and superficial wound sample collection. In addition, blood culture devices were used for collecting mediastinal fluid aspirated directly from the wound and biologic fluid obtained from the NPWT device. Fisher exact test was performed to test the rate of independence rate of micro-organism identification using the NPWT sponge device and taking blood culture results as a reference for micro-organism identification.
  
  
  RESULTS
  After the introduction of the new collection device in our hospital, an overall increase in the detection of micro-organisms (46.7%) was reported. During 2013-2014 our traditional microbiologic collection method did not detect a pathogen in 30.4% of patients. During 2015, the new sample collection approach, direct from the NPWT device, improved micro-organism detection by 10.4% and reduced DSWIs with undetected pathogens to 17.6% (p < 0.01).
  
  
  CONCLUSIONS
  As a result of proficiency gained in the last year, the most representative specimen in wound infection was represented by mediastinal fluid collected directly from the wound and the NPWT device. Given the correlation between the blood culture of micro-organisms detected using the ESwab device from the wound, mediastinal drainage, and drainage from the NPWT device, we can assume that the NPWT device may replace the other biologic sampling devices.
authors.affiliation: 1 Unità Operativa di Cardiochirurgia, Azienda Ospedaliera-Polo Universitario Luigi Sacco , Milano, Italy .
authors.forename: Giovanni
authors.initials: G
authors.lastname: Cagnoni
authors.affiliation: 2 Laboratorio di Microbiologia Clinica, Virologia e Diagnostica delle Bioemergenze, Azienda Ospedaliera-Polo Universitario Luigi Sacco , Milano, Italy .
authors.forename: Sara Giordana
authors.initials: SG
authors.lastname: Rimoldi
authors.affiliation: 2 Laboratorio di Microbiologia Clinica, Virologia e Diagnostica delle Bioemergenze, Azienda Ospedaliera-Polo Universitario Luigi Sacco , Milano, Italy .
authors.forename: Cristina
authors.initials: C
authors.lastname: Pagani
authors.affiliation: 3 Unità Operativa di Cardioanestesia, Azienda Ospedaliera-Polo Universitario Luigi Sacco , Milano, Italy .
authors.forename: Claudio
authors.initials: C
authors.lastname: Savi
authors.affiliation: 4 Istituto di Ricerca delle Acque-IRSA-CNR , Brugherio, Italy .
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Stefani
authors.affiliation: 5 Divisione I di Malattie Infettive, Azienda Ospedaliera-Polo Universitario Luigi Sacco , Milano, Italy .
authors.forename: Roberta
authors.initials: R
authors.lastname: Terzi
authors.affiliation: 6 Direzione Medica di Presidio, Azienda Ospedaliera-Polo Universitario Luigi Sacco , Milano, Italy .
authors.forename: Pietro
authors.initials: P
authors.lastname: Olivieri
authors.affiliation: 7 Unità Operativa di Farmacia, Azienda Ospedaliera-Polo Universitario Luigi Sacco , Milano, Italy .
authors.forename: Giulia
authors.initials: G
authors.lastname: Tosi
authors.affiliation: 8 Divisione di Anatomia Patologica, Azienda Ospedaliera-Polo Universitario Luigi Sacco , Milano, Italy .
authors.forename: Carlo
authors.initials: C
authors.lastname: Parravicini
authors.affiliation: 2 Laboratorio di Microbiologia Clinica, Virologia e Diagnostica delle Bioemergenze, Azienda Ospedaliera-Polo Universitario Luigi Sacco , Milano, Italy .
authors.forename: Annamaria
authors.initials: A
authors.lastname: Di Gregorio
authors.affiliation: 1 Unità Operativa di Cardiochirurgia, Azienda Ospedaliera-Polo Universitario Luigi Sacco , Milano, Italy .
authors.forename: Carlo
authors.initials: C
authors.lastname: Antona
authors.affiliation: 2 Laboratorio di Microbiologia Clinica, Virologia e Diagnostica delle Bioemergenze, Azienda Ospedaliera-Polo Universitario Luigi Sacco , Milano, Italy .
authors.forename: Maria Rita
authors.initials: MR
authors.lastname: Gismondo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008482:Mediastinum / Q000601:surgery; D008875:Middle Aged; D054843:Negative-Pressure Wound Therapy / Q000295:instrumentation* / Q000379:methods* / Q000706:statistics & numerical data; D013048:Specimen Handling / Q000379:methods*; D013249:Sternum / Q000601:surgery; D013530:Surgical Wound Infection / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology / Q000628:therapy*