Impact of Rapid Pathogen Detection in ICU Patients With Suspected Pneumonia on Antimicrobial Therapy

Pneumonia is the most common cause of sepsis requiring admission to the intensive care unit (ICU). Molecular pathogen detection techniques such as polymerase chain reaction (PCR) may help optimize antimicrobial therapy. Its utility for diagnosing respiratory viral infections such as influenza is well established, and was an essential diagnostic tool during the coronavirus 2019 (COVID-19) pandemic. However, its use remains limited for bacterial pathogens. The rationale to use PCR based bacterial detection to facilitate antibiotic stewardship is threefold. First, it may shorten the time to pathogen detection. Second, it has improved sensitivity over conventional culture techniques, particularly for pathogens that are difficult to culture. Third, it can detect resistant genes to inform antimicrobial sensitivity. Taken together, utilization of bacterial PCR may shorten time to appropriate antimicrobial therapy and minimize injudicious use of broad-spectrum antimicrobials in patients who do not have infection from MDRO.

The BioFire® FilmArray® Pneumonia Panel (FA Pneumonia Panel) is a PCR based in vitro assay which rapidly identifies 8 viral and 18 bacterial common pathogens in tracheal aspirate and bronchoalveolar lavage (BAL) samples. Clinical studies showed that FA Pneumonia Panel on BAL specimens have sensitivity of 75 to 100% and specificity of >91% for the pathogens tested. Retrospective analysis suggests utilizing FA Pneumonia Panel may facilitate discontinuation or de-escalation of antimicrobials in 48% of patients with an average reduction of 6 antibiotic days. However, currently there are no randomized controlled trials that assessed the efficacy of FA Pneumonia Panel on improving antimicrobial stewardship.

Addition of FA Pneumonia Panel to standard care should shorten time to pathogen and resistance detection, enhance sensitivity over conventional microbiological cultures and shorten time to appropriate antimicrobial therapy by reducing over-narrow and over-broad coverage. Robust clinical trials are now needed to test these hypotheses. We propose to conduct a pilot, randomized, controlled open-label trial designed to determine the feasibility, safety, and potential impact of rapid respiratory pathogen detection by FA Pneumonia Panel on antibiotic therapy in 40 mechanically ventilated critically ill patients with suspected pneumonia.

The goal is to determine the feasibility, safety, and potential impact of rapid respiratory pathogen detection by BioFire FilmArray Pneumonia Panel on antimicrobial therapy in 40 mechanically ventilated critically ill patients with suspected pneumonia.

Inclusion criteria

• adult (≥18 years old) ICU patients
• mechanical ventilation
• new antibiotic prescription within 24 hours for suspected community acquired, healthcare or ventilator associated pneumonia
• suspected pneumonia is defined as any of purulent sputum, cough, fever, shortness of breath, hypoxia, hypercapnia or abnormal white cell count AND chest infiltrates on imaging
• need for antibiotics other than suspected respiratory infection
• aspiration pneumonia
• suspected pneumonia due to tuberculosis
• known respiratory pathogens within 7 days prior to randomization
• given empirical antimicrobials for suspected Stenotrophomonas infection
• lack of sufficient respiratory samples for culture and FA Pneumonia Panel
• not expected to survive beyond 48 hours
• limitation of therapy prior to recruitment
• prisoners
• allergy to antibiotics
• immunosuppression from long term steroid of at least 5 mg/day or chemotherapy or HIV or haematological disease
• pregnancy