Lung ultrasound-guided PEEP titration in COVID-19 patients treated with CPAP.

Objectives: An increasing number of COVID-19 patients were treated with continuous positive airways pressure (CPAP). To evaluate the clinical effects of personalized positive end-expiratory pressure (PEEP) compared to standard fixed PEEP in COVID-19 patients requiring CPAP.

Methods: This is a single center, prospective, randomized clinical study. Sixty-three COVID-19 patients with hypoxemic respiratory failure and bilateral pneumonia were randomized in two Groups: Group A received CPAP with fixed PEEP of 10 cm H₂O, Group B performed the "PEEP trial", that consists in the evaluation of best PEEP defined as the PEEP value that precedes the echographic appearance of "lung pulse" determining a PaO₂/FiO₂ increase. Primary outcome was composite in-hospital mortality + intubation, secondary outcome was the percentage increase of PaO₂/FiO₂. As safety indicator, the incidence of pneumothorax was collected.

Results: Thirty-two patients were enrolled in Group A and 31 in Group B. The two groups were comparable for clinical characteristics and laboratory parameters. The primary outcome occurred in 36 (57.1 %) patients: 23 (71.8 %) in Group A and 13 (41.9 %) in Group B (p<0.01). Mortality was higher in Group A (53.1 vs. 19.3 %, p<0.01), while intubation rate was comparable between groups. Group B showed a higher PaO₂/FiO₂ increase than Group A (34.9 vs. 13.1 %, p<0.01). Five cases of pneumothorax were reported in Group A, none in Group B.

Conclusions: Lung ultrasound-guided PEEP trial is associated with lower mortality in COVID-19 patients treated with CPAP. Identifying the best PEEP is useful to increase oxygenation and reduce the incidence of complications.