Impact of a Multiplex PCR Assay for Rapid Diagnosis of Pneumonia on Antibiotic Use in Trauma ICU Patients

Author(s):
Danielle Detelich; Jim Beardsley; Joshua Chait; Alexandra Monetti; Andrew Nunn

Background:

Ventilator-associated pneumonia is a frequent complication in injured patients. The BioFire FilmArray Pneumonia Panel (PNA Panel) is a multiplex PCR that facilitates timely identification of certain respiratory pathogens prior to culture results. The PNA Panel was implemented in November 2021. All ICU respiratory cultures had a PNA Panel sent immediately at the time culture specimen was obtained.

Hypothesis:

Use of PNA Panel decreases time to antibiotic de-escalation for suspected VAP in injured patients.

Methods:

Adult Trauma ICU patients with quantitative respiratory cultures were included sequentially either before (PRE) or after (POST) implementation of the PNA Panel. Only the first respiratory culture from a patient was included, and patients were excluded if there was any documented infection other than a respiratory source.

Results:

60 total patients were analyzed, 30 PRE and 30 POST. The median time to first antibiotic change was significantly shorter in the POST group (61 vs 22.6 hours, p<0.001). In the POST cohort, 25/30 of empiric antibiotic regimens were eligible for change (de-escalation or escalation) based on PNA Panel. Of these, 88% were actually changed with a median time of 15.4 hours from sample collection. Median total days of antibiotic therapy (DOT) were not different overall (9 vs 10, p=0.207), but median  vancomycin DOT were decreased in the POST group (3 vs 2, p=<0.001). Diagnosis of pneumonia was confirmed in 13/30 PRE and 15/30 POST. In patients with pneumonia confirmed on culture, median total antibiotic, vancomycin, and cefepime DOT were significantly less in the POST group (12 vs 10 days p=0.008; 3 vs 2 days p=0.003, 4 vs 3 days 0.029, respectively).

Conclusions:

Utilization of BioFire PNA Panel in addition to bacterial culture significantly reduced time to achieve targeted antibiotic therapy in suspected pneumonia and reduced the number of days of vancomycin therapy. In patients who have pneumonia based on culture, PNA panel use was associated with reduced total antibiotic DOT.