The impact of performing bacterial identification and antimicrobial susceptibility testing on bronchoalveolar fluid cultures 24 h a day in a microbiology laboratory ★★★

• The night service led to an earlier appropriate therapy in 20% of cases.
• The night service led to an earlier de-escalation in 30% of cases.
• The night service led to earlier adequate therapy and de-escalation in 8% of cases.
• The antibiotic de-escalation concerned carbapenems and piperacillin + tazobactam.

We previously demonstrated the positive impact of performing bacterial identification and antimicrobial susceptibility testing (AST) after day hours (night service [NS]) for certain clinical samples on the treatment of infected patients. Our objective was to evaluate the impact of including positive bronchoalveolar lavage (BAL) cultures in our NS. Two major positive consequences were recorded: initiation of earlier appropriate treatment and earlier change to a reduced-spectrum but still effective regimen. Reductions in delay were defined as the differences between the hours actually spent and hours estimated as though laboratory tests had been performed in the absence of NS. Fifty BALs were included. The NS led to the implementation of earlier appropriate therapy in 10 cases (20%), to earlier de-escalation in 15 cases (30%), and to earlier appropriate therapy and de-escalation in 4 cases (8%). In conclusion, performing bacterial identification and AST for positive BAL after laboratory opening hours could be relevant.