Incidence of ventilator-associated tracheobronchitis (VAT) varies from 1.4 to 16.5% of intubated critically ill patients. VAT represents an intermediate process between lower respiratory tract colonisation and ventilator-associated pneumonia (VAP). The definition of VAT is still controversial. However, the most specific definition includes: fever (>38°C) with no other recognisable cause, purulent sputum production, positive culture of respiratory specimen at significant threshold, and no radiographic signs of new pneumonia. VAT is characterised by lower respiratory tract inflammation and increased sputum production resulting in weaning difficulties and longer mechanical ventilation (MV) duration.
Recent randomised trials have reported beneficial effects of antimicrobial therapy in VAT patients. In a randomised, blinded placebo-controlled trial, aerosolised antibiotics significantly reduced the incidence of subsequent VAP. Furthermore, aerosolised antibiotics increased weaning from MV, reduced systemic antibiotic usage and antibiotic resistance. The impact of systemic antibiotics on outcomes of VAT patients was evaluated in a randomised, unblinded controlled study. Antibiotic treatment increased MV free days and reduced the incidence of subsequent VAP and intensive care unit mortality.