The proposed study will be conducted to investigate the mechanism of patients' responses to prone positioning with coronavirus disease 2019 (COVID-19) acute respiratory distress syndrome (ARDS) and non-COVID-19 ARDS utilizing lung ultrasound.

This is a prospective observational study of adult patients with coronavirus disease 2019 (COVID-19) acute respiratory distress syndrome (ARDS) and non-COVID-19 ARDS who are intubated, in the prone position and receiving mechanical ventilation in the intensive care units at Rush University Medical Center. In this study design, we will prospectively enroll subjects, who fulfill eligibility criteria, to investigate the mechanism of their responses to the first three prone positioning sessions, utilizing lung ultrasound (LUS). Inclusion criteria include: adult subjects 18 years and older with a diagnosis of ARDS, endotracheally intubated and receiving assisted mechanical ventilation, meet criteria for prone positioning (ratio of arterial oxygen tension to the fraction of inspired oxygen (PaO2/FiO2) of ≤ 150 mm Hg with ventilator parameters of positive end-expiratory pressure (PEEP) ≥ 10 cm H2O and FiO2 of .60, and order for prone positioning. Patients will be excluded from the study if they meet the following criteria: pregnant, tracheostomy, receiving extracorporeal membrane oxygenation (ECMO), palliative care, received prone positioning more than once during intubation in an outside hospital, or receive invasive ventilation in an outside hospital for more than 72 hours. Enrolled subjects will undergo LUS 1 hour before and 1 hour after prone positioning by a trained clinician and will be assessed using a LUS score based on LUS pattern. LUS will then be performed again 1 hour before supination (16 hours) and assessed by a LUS score. This process will be repeated on the first 3 prone sessions. Patients will be enrolled in the study for 4 weeks in order to observe patient outcomes.

Inclusion Criteria:

1. Adult subjects 18 years and older, diagnosis of ARDS
2. endotracheally intubated and receiving assisted mechanical ventilation
3. meet criteria for prone positioning: PaO2/FIO2 (P/F ratio) of ≤ 150 mm Hg with ventilator parameters of PEEP ≥ 10 cm H2O and FiO2 of .60
4. receive an order for prone positioning.

Exclusion Criteria:

1. Pregnant
2. Tracheostomy
3. Receiving ECMO
4. Palliative care
5. Receive prone positioning more than once during intubation in an outside hospital
6. Receive invasive ventilation in an outside hospital for more than 72 hours

Intubated adults (18 years or older) with a diagnosis of ARDS receiving mechanical ventilation and meet criteria for prone positioning.