Risk factors for surgical site infections in hip and knee arthroprosthesis: role of microbial air contamination and adherence to guidelines for antimicrobial prophylaxis

Abstract number: R2529

Agodi A., Auxilia F., Barchitta M., Cristina M.L., D'Alessandro D., Moscato U., Mura I., Nobile M., Pasquarella C., Torregrossa V.

Objectives: The main aim of the study is to evaluate the role of microbial air contamination on the risk of surgical site infection (SSI) in hip and knee arthroprosthesis controlling for adherence to guidelines for antimicrobial prophylaxis. The project has been funded by the Italian CCM (Centro Controllo Malattie, Ministry of Health).

Methods: Hospitals were invited to join the project by GISIO members. SSI surveillance was conducted according to the HELICS protocol (version 9.1, 2004). Microbial air contamination was evaluated at the patient area, once at rest and during each operation, by passive sampling to determine the Index of microbial air contamination (IMA) (Pasquarella et al., 2000) and in some cases also by active sampling to determine the colony forming units (cfu)/m3. Surgical antimicrobial prophylaxis refers to a very brief course of an antimicrobial agent initiated just before an operation begins. A web-based data collection procedure was adopted using three electronic data forms. The two years project started in July 2010, preceded by a three-month pilot study to assess the overall feasibility of the programme.

Results: The project has included so far 8 Hospitals and 20 operating rooms (OR). According to the OR ventilation system in place, 76.5% of OR were with unidirectional airflow, 6.0% with turbulent air ventilation, and 17.6% mixed. A total of 289 surgical procedures, 67.0% hip and 33.0% knee arthroprosthesis, were included until December 2010. Mean duration of operations was 93 minutes for hip and 117 minutes for knee arthroprosthesis. IMA values in OR at rest were as follows: range = 0–8, mean±SD = 0.8±2.1, median = 0; during surgical procedures the following values were registered: range = 0–156, mean±SD = 7.2±14.7, median = 3. A total of 99.6% of patients received antibiotic prophylaxis: 30–60 minutes (36.7%), 1–2 hours (18.5%) and >2 hours (44.8%), before incision. The most frequently administered antimicrobial agents were cefazolin (44.7%), tobramycin (29.1%) and teicoplanin (19.6%).

Conclusion: Although one year of follow-up after implant is requested for SSIs surveillance, the study has depicted the epidemiological scenario in which a complex network of risk factors for SSIs is embedded, already highlighting potential areas for improvement both for air quality and antibiotic prophylaxis.

Session Details

Date: 07/05/2011
Time: 00:00-00:00
Session name: Abstracts of 21st ECCMID / 27th ICC
Location: Milan, Italy, 7 - 10 May 2011
Presentation type:
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