Driving pressure and long-term outcomes in moderate/severe acute respiratory distress syndrome

BackgroundAcute respiratory distress syndrome (ARDS) patients may present impaired in lung function and structure after hospital discharge that may be related to mechanical ventilation strategy. The aim of this study was to evaluate the association between functional and structural lung impairment, N-terminal-peptide type III procollagen (NT-PCP-III) and driving pressure during protective mechanical ventilation. It was a secondary analysis of data from randomized controlled trial that included patients with moderate/severe ARDS with at least one follow-up visit performed. We obtained serial measurements of plasma NT-PCP-III levels. Whole-lung computed tomography analysis and pulmonary function test were performed at 1 and 6months of follow-up. A health-related quality of life survey after 6months was also performed.ResultsThirty-three patients were enrolled, and 21 patients survived after 6months. In extubation day an association between driving pressure and NT-PCP-III was observed. At 1 and 6months forced vital capacity (FVC) was negatively correlated to driving pressure (p<0.01). At 6months driving pressure was associated with lower FVC independently on tidal volume, plateau pressure and baseline static respiratory compliance after adjustments (r(2)=0.51, p=0.02). There was a significant correlation between driving pressure and lung densities and nonaerated/poorly aerated lung volume after 6months. Driving pressure was also related to general health domain of SF-36 at 6months.ConclusionEven in patients ventilated with protective tidal volume, higher driving pressure is associated with worse long-term pulmonary function and structure.