Monitoring lung mechanics by oscillometry in COVID 19 ARDS receiving non-invasive ventilation: a pilot study

Non-invasive respiratory supports have been increasingly used in patients with COVID-19 as they may reduce intubations. This pilot study aims to evaluate the feasibility of monitoring longitudinal changes in respiratory mechanics by oscillometry in COVID-19 patients with moderate ARDS receiving non-invasive supports. A convenience series of ten patients was enrolled at Respiratory High Dependency Unit (RHDU) of the Hospital of Cattinara (Trieste, Italy). Measurements (Resmon ProFULL, Restech Srl, Italy) were done at least twice: the first one as the patient tolerates transient removal of non-invasive ventilation, and the last one at RHDU discharge. All patients well tolerated the measurements. The resistance variation coefficient was always <10%, excluding outlier measures if needed. The majority of the measurements were within the normal range. Lung mechanics generally improved with time (Figure 1). Four patients had abnormal lung mechanics at discharge, not exclusively linked to pre-existing respiratory comorbidities, confirming that the pathophysiologic mechanisms leading to COVID-19 ARDS hypoxemia are complex and variable. Longitudinal assessment of respiratory mechanics by oscillometry is feasible and may help improve personalising treatments during non-invasive respiratory support, especially in presence of respiratory comorbidities, when lung mechanics may be poorly coupled to gas exchange.