Lung recruitment

Excerpt

In physiological terms, lung recruitment is “the increase in volume for the same pressure” [1]. In clinical terms, the case of bacterial pneumonia may help to explain what lung recruitment is. Infection in a lung lobe creates a consolidated mixture of bacteria and inflammatory cells. This part of the lung will not be accessible to gas flow, and will not be recruitable. However, the rest of the lung may become quickly inflamed but remaining accessible to gas flow. The effect of gravity on this latter part, the lack of respiratory muscle activity in a sedated patient and the load induced by the chest wall in obese patients will generate mostly dependent atelectasis—but a great heterogeneity inside the lung could also exist. This part constitutes the recruitable lung, which can be reopened and kept open by different approaches (recruiting maneuvers, prone positioning, higher positive end-expiratory pressure (PEEP)) [1]. Lung morphology [2] rather than the cause of lung disease (extrapulmonary or pulmonary) [3] could explain a considerable variability in recruitability among patients. …