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 (Delta LUStot) and in four ventral (Delta LUSV), intermediate (Delta LUSI) and dorsal (Delta LUSD) zones were calculated at each time points. Three categories were described: Improve (Delta LUS < 0), Equal (Delta LUS = 0) or Worse (Delta LUS > 0). LUS scores were correlated with total changes in lung CT aeration (Delta CTair) and with normally, poorly and not aerated regions (Delta CTnorm, Delta CTpoor and Delta CTnot, respectively). Eleven patients were enrolled. Delta LUStot had significant correlation with Delta CTair (r = - 0.74, p < 0.01). Delta LUSV, Delta LUSI and Delta LUSD showed significant correlations with Delta CTair (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) Delta CTair values, respectively. Compared to Equal, Improve and Worse categories had lower (p < 0.01) and higher (p < 0.01) Delta CTnot values, respectively. LUS score had a good correlation with lung CT in detecting changes of lung aeration.