Clinical and microbiological impact of syndromic pneumonia molecular testing in intensive care: A before and after study

Abstract

• Molecular testing for respiratory pathogens provided quicker diagnosis in intensive care. • No effect was seen on length of stay. • A non significant reduction in all antibiotic use, with a significant decrease in macrolide usage was seen. Pneumonia is one of the most common diagnoses in ICU and carries high mortality rates, as well as significant healthcare costs. Microbiological diagnosis allows targeting of antimicrobial therapy, which is known to improve patient outcomes. Standard culture of sputum samples has limitations due to time required to obtain results. BioFire offers a syndromic panel of multiplex PCR to identify pathogens rapidly. This study evaluated patient outcomes relating to ICU admission, antimicrobial management and complications. The study analysed admission details of radiologically confirmed pneumonia patients admitted to ICUs in Hull Hospitals between 1st August and 31st December 2018 and 2019, before and after the introduction of BioFire testing. The review identified 139 and 120 patients in 2018 and 2019 periods respectively, who had radiologically confirmed pneumonia and sputum samples sent to the laboratory. No statistical difference was seen in the length of ITU admission or the duration of mechanical ventilation between the cohorts as a whole. However, sub-group analysis revealed a decrease in length of stay of 5.6 days in hospital and ventilator acquired pneumonias. We observed a reduction in time to change of antibiotics of 1.81 days (p < 0.001) after introduction of BioFire. Furthermore, we identified discrepancies when using BioFire, allowing for identification of additional pathogens in 23 patients not seen on standard culture. Rapid molecular diagnostics allow for a timelier antimicrobial therapy adjustment as well as ensuring appropriate infection control measures. Syndromic PCR-based testing shows potential for improving patient outcomes in pneumonia patients requiring ICU admission.