Ventilator-associated Tracheobronchitis

Abstract

The incidence of ventilator-associated tracheobronchitis (VAT) varies from 10% to 16.5% of intubated critically ill patients. This infection represents an intermediate process between lower respiratory tract colonization and ventilator-associated pneumonia (VAP). VAT definition is still controversial. However, the most specific definition includes all the following criteria: fever (>38°C) with no other recognizable cause, purulent sputum production, positive culture of a respiratory specimen at significant threshold concentrations, and no radiographic signs of a new pneumonia. This infection is frequently caused by Pseudomonas aeruginosa, and is characterized by lower respiratory tract inflammation and increased sputum production resulting in weaning difficulties and longer duration of mechanical ventilation. Two recent randomized trials reported beneficial effects of antimicrobial therapy in patients with VAT. In a randomized blinded placebo-controlled trial, aerosolized antibiotics significantly reduced the incidence of subsequent VAP. Further, aerosolized antibiotics increased weaning from mechanical ventilation, reduced usage of systemic antibiotics, and antibiotic resistance. The impact of systemic antibiotics on outcomes of VAT patients was evaluated in a randomized unblinded controlled study. Antibiotic treatment increased mechanical ventilation-free days, and reduced the incidence of subsequent VAP and intensive care unit mortality. The beneficial effects of antibiotic treatment in VAT patients should be confirmed, and the best duration of antimicrobial therapy should be determined by future studies.