Respiratory mechanics in a cohort of critically ill subjects with COVID-19 infection

Abstract

BACKGROUND: Patients with coronavirus disease 2019 (COVID-19) often develop acute hypo-xemic respiratory failure and receive invasive mechanical ventilation. Much remains unknown about their respiratory mechanics, including the trajectories of pulmonary compliance and PaO2 /FIO2, the prognostic value of these parameters, and the effects of prone positioning. We described respiratory mechanics among subjects with COVID-19 who were intubated during the first month of hospitalization. METHODS: We included patients with COVID-19 who were mechanically ventilated between February and May 2020. Daily values of pulmonary compli-ance, PaO2, FIO2, and the use of prone positioning were abstracted from electronic medical records. The trends were analyzed separately over days 1–10 and days 1–35 of intubation, strati-fied by prone positioning use, survival, and initial PaO2 /FIO2. RESULTS: Among 49 subjects on mechanical ventilation day 1, the mean compliance was 41 mL/cm H2O, decreasing to 25 mL/cm H2O by day 14, the median duration of mechanical ventilation. In contrast, the PaO2 /FIO2 on day 1 was similar to day 14. The overall mean compliance was greater among the non-survivors versus the survivors (27 mL/cm H2O vs 24 mL/cm H2O; P =.005), whereas PaO2 /FIO2 was higher among the survivors versus the non-survivors over days 1–10 (159 mm Hg vs 138 mm Hg; P =.002) and days 1–35 (175 mm Hg vs 153 mm Hg; P