Ventilator-associated infection

Ventilator-associated pneumonia (VAP) is the most serious and controversial of the infections of the critically ill patient. The accuracy of standard methods of diagnosis remains under constant scrutiny, and at the same time there is increasing debate about whether it is a preventable disease. This review focuses on the pathophysiology of respiratory tract infection in the ventilated patient, and how the latest advances have grown from our current understanding of its pathogenesis.

Data from many recent investigations have focused on the role of proximal airway infection, ventilator-associated tracheobronchitis (VAT), in respiratory tract infection. The goals of recent trials include reducing the morbidity associated with the progression of airway colonization to VAT or with the progression of VAT to VAP. Continuous subglottic secretion suctioning, innovative types of endotracheal tubes and targeted therapy for VAT in recent investigations have shown promise in improving clinical outcomes in the critically ill patient. However, even with diligent attention to all the modifiable risk factors for respiratory infection, complete elimination of VAT and VAP remains unlikely. As long as a patient requires an endotracheal tube that disturbs airway integrity, host defenses will be impaired, and resistant virulent organisms that result from our liberal use of systemic antibiotics will continue to challenge critical care specialists.

This review will focus on: the current understanding of the pathogenesis of VAT and VAP, modifiable risk factors and new approaches to treatment, and bacterial resistance challenges.