Early Clinical Response is Associated With a Decreased Risk of Recurrent Pseudomonas aeruginosa Ventilator-Associated Pneumonia.

Abstract

Background: Current data suggest that short-course therapy for Pseudomonas aeruginosa ventilator-associated pneumonia (PA-VAP) may increase the risk of recurrent pneumonia. To decrease antibiotic exposure without adversely impacting clinical outcomes, risk stratification based on clinical response may identify optimal candidates for short-course therapy.

Objective: The purpose of this study was to determine whether early response to therapy correlated with the risk of recurrence in patients with PA-VAP.

Methods: This was a retrospective cohort study of patients with PA-VAP admitted to the Detroit Medical Center from January 2020 to July 2022. Those with improvements in at least 2 out of 3 objective measures of clinical response (PaO₂/FiO₂, fever, and leukocyte count) at 72 hours after therapy initiation were classified as early responders. The primary outcome was PA-VAP recurrence within 28 days of initial VAP onset.

Results: A total of 73 patients were included in the analysis: early response (n = 43) and delayed response (n = 30). Patients with an early response had a significantly decreased risk of 28-day PA-VAP recurrence compared to those with a delayed response (21% vs 43%, P = 0.04). Multivariable logistic regression found that PaO₂/FiO₂ > 240 mm Hg at 72 hours was associated with a decreased risk of 28-day PA-VAP recurrence (odds ratio [OR] = 0.25, 95% confidence interval [CI] = 0.07 to 0.90), whereas duration of antibiotics ≤8 days was associated with an increased risk of 28-day PA-VAP recurrence (OR = 4.74, 95% CI = 1.31 to 17.18).

Conclusion and relevance: This study found that early clinical response and improvement in PaO₂/FiO₂ were associated with a decreased risk of PA-VAP recurrence. Individualized treatment durations based on clinical response may allow clinicians to safely utilize shorter antibiotic courses for PA-VAP.