New insights into pneumonia in patients on prolonged mechanical ventilation: need for a new paradigm addressing dysbiosis

Abstract

1. Clinical Research/Epidemiology in Pneumonia & Sepsis–CRIPS–Vall d’Hebron Institut de Recerca–VHIR–Barcelona, España. 2. Centro de Investigación Biomedica En Red de Enfermedades Respiratorias – CIBERES – Instituto de Salud Carlos III, Madrid, España. 3. Centre Hospitalier Universitaire, Nîmes, France. 4. Laboratoire de Bactériologie et Laboratoire de Recherche en Génomique, Service des Maladies Infectieuses et Service de Médecine de Laboratoire, Hôpitaux Universitaires Genève, Genève, Suisse. 5. Divisão de Doenças Infecciosas, Departamento de Medicina Interna, Universidade Estadual de Londrina, Londrina (PR) Brasil. Ventilator-associated pneumonia (VAP) is related to poor outcomes and is most commonly treated with the use of antibiotic therapy in ICUs. The Infectious Diseases Society of America defined VAP as a new lung infiltrate of infectious origin occurring ≥ 48 h after endotracheal intubation.(1) Systemic antibiotic use may increase the risk of VAP by depleting commensal microorganisms and selecting gram-negative bacteria that may have multiple mechanisms of resistance. Traditional endotracheal aspirate cultures are unspecific and lead to widespread use of antimicrobial agents. As an alternative to systemic antibiotics, aerosolization has been suggested,(2) despite the current lack of evidence of reduction in mortality or in the number of days on mechanical ventilation (MV).(3) In the present issue of the Jornal Brasileiro de Pneumologia, Núñez et al.(4) address the occurrence of VAP in tracheostomized patients on prolonged MV (median = 56 days). The authors reported 30-day and 90-day mortality rates of 30.0% and 63.7%, respectively. The SOFA score and the use of vasoactive drugs were significantly associated with 30-day mortality, whereas advanced age, SOFA score, use of vasoactive drugs and COPD were associated with 90-day mortality. (4) Pseudomonas aeruginosa was confirmed as the major pathogen isolated, especially in COPD patients. Interestingly, although Acinetobacter baumannii was isolated from microbiological cultures from various patients,(4) this was not associated with mortality, suggesting that patients die of pneumonia as an ultimate event rather than as a consequence.