Clinical performance of lung ultrasound in predicting time-dependent changes in lung aeration in ARDS patients

To evaluate whether lung ultrasound is reliable bedside tool to monitor changes of lung aeration at the early and late stages of ARDS. LUS was performed in ARDS patients that underwent at least two consecutive CT scan at ICU admission and at least 1 week after admission. Twelve fields were evaluated and graded from 0 (normal) to 3 (consolidation). Changes of LUS score in twelve fields (ΔLUS_tot) and in four ventral (ΔLUS_V), intermediate (ΔLUS_I) and dorsal (ΔLUS_D) zones were calculated at each time points. Three categories were described: Improve (ΔLUS < 0), Equal (ΔLUS = 0) or Worse (ΔLUS > 0). LUS scores were correlated with total changes in lung CT aeration (ΔCT_air) and with normally, poorly and not aerated regions (ΔCT_norm, ΔCT_poor and ΔCT_not, respectively). Eleven patients were enrolled. ΔLUS_tot had significant correlation with ΔCT_air (r = - 0.74, p < 0.01). ΔLUS_V, ΔLUS_I and ΔLUS_D showed significant correlations with ΔCT_air (r = - 0.66, r = - 0.69, r = - 0.63, respectively; p < 0.05). Compared to Equal, Improve and Worse categories had significantly higher (p < 0.01) and lower (p < 0.05) ΔCTair values, respectively. Compared to Equal, Improve and Worse categories had lower (p < 0.01) and higher (p < 0.01) ΔCT_not values, respectively. LUS score had a good correlation with lung CT in detecting changes of lung aeration.