Recruitment by sustained inflation: time for a change

Excerpt

A key objective of avoiding ventilator-induced lung injury (VILI) is to minimize the number of lung units subjected to amplified tensions at points of stress focusing. These high-risk units tend to occur at the junctions of closed and open lung units, and although they are relatively few in number, many investigators believe that VILI propagates from these zones rather than from continuously aerated alveoli that are repeatedly overstretched. Eliminating these interfaces is the primary objective of an “open lung” approach to safe ventilation [1]. It has been known for more than two decades that some collapsed but potentially aeratable units within the acutely injured lung may require opening pressures that exceed safe limits for ongoing tidal ventilation and that the process of tissue recruitment continues (albeit at a progressively declining rate) until further expansion is constrained by total lung capacity [2]. Once opened, most (but not all) lung units may continue to remain patent at combinations of positive end-expiratory pressure (PEEP) and tidal volume that do not pose undue risk for iatrogenic injury. …