Ventilator-associated Pneumonia caused by commensal oropharyngeal Flora: a retrospective Analysis of a prospectively collected Database

Abstract

BackgroundThe significance of commensal oropharyngeal flora (COF) as a potential cause of ventilator-associated pneumonia (VAP) is scarcely investigated and consequently unknown. Therefore, the aim of this study was to explore whether COF may cause VAP.MethodsRetrospective clinical, microbiological and radiographic analysis of all prospectively collected suspected VAP cases in which bronchoalveolar lavage fluid exclusively yielded ≥ 104 cfu/ml COF during a 9.5-year period. Characteristics of 899 recent intensive care unit (ICU) admissions were used as a reference population.ResultsOut of the prospectively collected database containing 159 VAP cases, 23 patients were included. In these patients, VAP developed after a median of 8 days of mechanical ventilation. The patients faced a prolonged total ICU length of stay (35 days [P < .001]), hospital length of stay (45 days [P = .001]), and a trend to higher mortality (39 % vs. 26 %, [P = .158]; standardized mortality ratio 1.26 vs. 0.77, [P = .137]) compared to the reference population. After clinical, microbiological and radiographic analysis, COF was the most likely cause of respiratory deterioration in 15 patients (9.4 % of all VAP cases) and a possible cause in 2 patients.ConclusionCommensal oropharyngeal flora appears to be a potential cause of VAP in limited numbers of ICU patients as is probably associated with an increased length of stay in both ICU and hospital. As COF-VAP develops late in the course of ICU admission, it is possibly associated with the immunocompromised status of ICU patients.

Preventive Effect of Probiotics on Ventilator-Associated Pneumonia: A Meta-analysis of 2428 Patients

“…VAP is caused by tracheal intubation and MV as a result of the disappearance of the natural barrier between the oropharynx and the trachea, resulting in bacteria-laden oropharyngeal secretions to be inhaled into the lungs. 38 According to Scholte et al, 54 commensal oropharyngeal flora appear to be a potential cause of VAP in ICU patients. In airway secretion culture-positive bacterial classifications, we found that probiotics appeared to reduce infection with GN and MDR bacteria.…”

Variations of the lung microbiome and immune response in mechanically ventilated surgical patients

“…Taken together, culture samples reported as RTF had more in common with C+ samples than with C-, suggesting that they may represent a higher risk for pneumonia (as currently defined clinically) in this patient cohort. Along these lines previous examinations of commensal oral flora (by traditional culture methods) have been associated with the development of VAP in the ICU [ 34 ]. This may warrant considering whether patients with bacteria designated as RTF should be clinically treated similar to patients who are C+.…”

“…The relative abundance of bacteria in the RTF samples was often dominated by two to three bacterial genera. These genera are often considered clinically significant and commensal oral flora has been associated with the development of VAP, especially in immunocompromised individuals [ 34 ]. However, given the mix of genera that comprise the RTF, and their lower levels of CFUs, patients with RTF are often not treated with antibiotics to resolve the bacterial growth.…”

Erratum to: ‘Ventilator-associated Pneumonia caused by commensal oropharyngeal a retrospective Analysis of a prospectively collected Database’

“…Unfortunately, the original version of this article [ 1 ] contained an error. The title was stated incorrectly.…”