Regional Ventilation Delay Index: Detection of Tidal Recruitment using Electrical Impedance Tomography.

Apart from restoring adequate gas exchange, mechanical ventilation should avoid factors known to further aggravate lung injury such as inspiratory overdistension as well as cyclic opening and closing (tidal recruitment) of ventilatory units during tidal ventilation. Both are considered as major risk factors in the pathogenesis of ventilation-associated lung injury (VALI) [1–3]. The risk of inspiratory overdistension can be reduced by using small tidal volumes and by limiting inspiratory plateau pressures [4]. Low tidal volume ventilation, however, is known to promote end-expiratory alveolar collapse [5, 6], thus, potential for alveolar recruitment and risk for cyclic opening and closing of ventilatory units (tidal recruitment) is increased. To avoid end-expiratory alveolar collapse, an adequate positive end-expiratory pressure (PEEP) is needed [7, 8]. Although experimental investigations have shown that elevated PEEP levels protect from VALI [9, 10], studies comparing high-PEEP and low-PEEP strategies have failed so far to show a consistent improvement in mortality [11–13]. [ABSTRACT FROM AUTHOR]