Garnier M, Hafiani EM, Arbelot C, et al. - In this prospective cohort study, researchers focused on acute chest syndrome (ACS)-associated lung ultrasound (LU) patterns as well as investigated LU performance to evaluate ACS outcome. Participants were 56 patients with ACS admitted to the ICU in a tertiary university hospital (Paris, France). At admission (D0) and following 48 h (D2), LU and bedside spirometry were performed. All patients exhibited a severe loss of lung aeration, mainly in inferior lobes. Reduced vital capacity was observed in relation to a severe loss of lung aeration. On D0 and on D2, the estimated LU Score was 24 [20–28] and 20 [15–24], respectively. A complicated outcome was reported in 25% of patients (14/56). A negative LU re-aeration score at D2 was identified as an independent marker of severity of ACS in ICU. Findings revealed a link between ACS and severe loss of lung aeration, the resolution of which led to a favourable outcome. ACS patients at risk of complicated outcome may be precisely and early identified using serial bedside LU.