[Assessing the usefulness of a permanently opened clinical microbiology laboratory]

Abstract

Since 2005, the clinical microbiology laboratory of the Angers teaching hospital has implemented after hours service requiring the overnight presence of a technician specialized in bacteriology. During that time, bacterial identifications and antibiotic susceptibility testing to antimicrobial agents can be performed for critical samples.

Objectives: The authors wanted to evaluate the impact of the after-hours service on the decrease of delay from sampling to results, and from sampling to the implementation of an appropriate antimicrobial therapy. A therapy could be initiated, changed for more efficient agents, or changed to narrower-spectrum agents (major benefits).

Methods: A 4-month prospective study was made. All samples for which identification and/or susceptibility testing were performed during after-hours service (continued analyses) were included in the study. Delays observed were compared with theoretical delays estimated in the absence of the after-hours service.

Results: A minimum 24 hour-decrease of the delay for results was observed for 97 % of the 430 samples included. Overall, a major benefit was obtained for more than 25 % of the analyses, representing a cumulated 111-day benefit in days of efficient treatments and a cumulated 27-day benefit in days of prescription of narrower-spectrum agents.

Discussion: This organization, unique in French hospitals, is directly related to the improvement of antimicrobial treatments, like antibiotic practice guidelines or infection disease specialists. It was evaluated as a relevant strategy, potentially cost saving, with a significant impact on both the efficiency of treatments and microbial ecology.