Significance of Prior Digestive Colonization With Extended-Spectrum β-Lactamase–Producing Enterobacteriaceae in Patients With Ventilator-Associated Pneumonia

Significance of Prior Digestive Colonization With Extended-Spectrum β-Lactamase–Producing Enterobacteriaceae in Patients With Ventilator-Associated Pneumonia

Critical Care Medicine: April 2016 - Volume 44 - Issue 4 - p 699–70

Bruyère, R et al

Objectives: Ventilator-associated pneumonia is frequent in ICUs. Extended-spectrum β-lactamase–producing Enterobacteriaceae are difficult-to-treat pathogens likely to cause ventilator-associated pneumonia. We sought to assess the interest of screening for extended-spectrum β-lactamase–producing Enterobacteriaceae rectal carriage as a way to predict their involvement in ventilator-associated pneumonia. Design: A retrospective cohort study of patients with suspected ventilator-associated pneumonia in a medical ICU was conducted. Patients: Every patient admitted between January 2006 and August 2013 was eligible if subjected to mechanical ventilation for more than 48 hours. Each patient with suspected ventilator-associated pneumonia was included in the cohort. Active surveillance culture for extended-spectrum β-lactamase–producing Enterobacteriaceae detection was routinely performed in all patients at admission and then weekly throughout the study period. Extended-spectrum β-lactamase colonization was defined by the isolation of at least one extended-spectrum β-lactamase–producing Enterobacteriaceae from rectal swab culture. Interventions: None. Measurements and Main Results: Among 587 patients with suspected ventilator-associated pneumonia, 40 (6.8%) were colonized with extended-spectrum β-lactamase–producing Enterobacteriaceae prior to the development of pneumonia. Over the study period, 20 patients (3.4%) had ventilator-associated pneumonia caused by extended-spectrum β-lactamase–producing Enterobacteriaceae; of whom, 17 were previously detected as being colonized with extended-spectrum β-lactamase–producing Enterobacteriaceae. Sensitivity and specificity of prior extended-spectrum β-lactamase–producing Enterobacteriaceae colonization as a predictor of extended-spectrum β-lactamase–producing Enterobacteriaceae involvement in ventilator-associated pneumonia were 85.0% and 95.7%, respectively. The positive and negative predictive values were 41.5% and 99.4%, respectively. The positive likelihood ratio was 19.8. Conclusions: Screening for extended-spectrum β-lactamase–producing Enterobacteriaceae digestive colonization by weekly active surveillance cultures could reliably exclude the risk of the involvement of such pathogens in patients with ventilator-associated pneumonia in low-prevalence area.