We would like to congratulate Pneumatikos et al. on the review article on ventilator-associated pneumonia (VAP). An increased understanding of the pathogenesis and prevention of VAP has resulted in the proposal for a ventilator bundle with particular emphasis on semire-cumbancy, early awakening, and liberation from mechanical ventilation. The most common cause of VAP is clearly upper aerodigestive tract colonization, followed by pulmonary aspiration past the cuff of the endotracheal tube (ETT) or tracheostomy tube. After this, the inner lumen of the ETT develops a biofilm and the circuit becomes contaminated. Microaspiration and VAP are intimately linked, and this has led to a search for improvements in the design of the traditional ETTs and tracheostomy tubes. High-volume, low-pressure cuffed ETTs came into practice in the early 1970s after the high incidence of tracheal injury related to low-volume, high-pressure cuffed ETTs. Seegobin et al. showed that high-volume, low-pressure cuffed tubes were completely ineffective in preventing leakage of aspirates as compared with low-volume, high-pressure tubes; however, the practice could not change because low-volume, high-pressure tubes do not have the ability to control the pressure transmitted across to the tracheal wall.
展开▼
