Fig. 2

Distribution of aeration compartments, expressed as percent of the total lung mass, at PEEP of 8 and 16 cmH₂O. Data are reported overall and stratified in the recruiter and non-recruiter groups. Bars represent means, error bars the standard error of mean. *Significant difference between the two PEEP levels (p < 0.05). PEEP: positive end-expiratory pressure