Mechanical ventilation strategies for lung protection

A large body of animal literature has shown that lungs stretched beyond their normal maximum are likely to be injured and release inflammatory cytokines into the systemic circulation. Moreover, this injury seems to be compounded if alveolar collapse also occurs. This has give rise to the notion that adequate positive end expiratory pressure (PEEP) to prevent derecruitment coupled with a tidal volume-PEEP combination that limits maximal distention to below the normal maximum is the ideal way to provide positive pressure ventilatory support. Some have argued that static pressure-volume plots to describe upper and lower inflection points are particularly important in implementing this approach. Supporting this concept is the recently completed NIH trial showing improved survival in acute respiratory distress syndrome (ARDS) when a small tidal volume strategy was used.