EIT-guided chest physiotherapy for airway clearance during awake prone ventilation in ARDS: a randomized controlled...

Acute respiratory distress syndrome (ARDS) is associated with severe hypoxemia, and awake prone positioning (APP) with high-flow nasal cannula (HFNC) or noninvasive ventilation (NIV) is increasingly used to delay intubation. However, airway clearance and patient tolerance remain major challenges. This study aimed to assess whether an electrical impedance tomography (EIT)-guided chest physiotherapy (CPT) protocol could improve oxygenation, comfort, and prone tolerance compared with standard CPT in non-intubated ARDS patients.

Ninety-two adults with primary ARDS, defined by the Berlin criteria and ratio of arterial oxygen tension to the fraction of inspired oxygen (PaO₂/FiO₂) <150 mmHg on HFNC or NIV, were randomized to EIT-guided CPT or standard CPT. Interventions included repositioning, vibration-assisted clearance, and nebulization, applied with or without EIT guidance. The pre-specified primary endpoint was the change in PaO₂/FiO₂ ratio from day 1 to day 5. Secondary endpoints included the change from day 1 to day 3, patient comfort, prone duration, intensive care unit (ICU) length of stay, and treatment failure (progression to intubation and invasive mechanical ventilation). Analyses were performed in a modified intention-to-treat population, defined as all randomized patients with at least one post-baseline assessment. Outcome assessors were blinded to group allocation.

Eighty-seven patients were included in the final analysis (44 EIT, 43 control). The EIT group showed a significantly greater improvement in PaO₂/FiO₂ from baseline to day 5 (mean between-group difference 31.5 mmHg, P<0.05). Secondary outcomes favored the EIT group, with longer prone duration (13.2 vs. 9.0 hours/day), higher comfort scores (7.0 vs. 5.9), and lower failure rates (4.5% vs. 9.1%). ICU length of stay was similar between groups (13-14 days), reflecting local practice. No serious adverse events were observed.

In patients with ARDS supported by HFNC or NIV, an EIT-guided CPT protocol improved oxygenation, enhanced comfort, and prolonged tolerance of APP. These findings support the clinical utility of EIT in optimizing noninvasive respiratory strategies, though multicenter studies are needed to confirm long-term benefits.