Fig. 1

Tidal recruitment in an anesthetized adult. All ultrasound images were obtained at the same lung region. Figures show atelectasis and tidal recruitment despite a protective ventilation pattern (A, B). A pulmonary consolidation (c) or atelectasis appears as a hypoechoic area mixed with airway bronchograms. Visual differences in the degree of lung aeration and the area of atelectasis between end-expiration and end-inspiration define the presence of tidal recruitment. C and D were obtained after a lung recruitment maneuver. They represent almost normal lung ultrasound images during end-expiration and end-inspiration, with the typical structures of skin, sub-cutaneous tissue (sc), pleural line and lung tissue. No differences in aeration were found during the breathing cycle