Determine the Effects of Prone Positioning and NO in COVID-19 ARDS by EIT

Determine the Effects of Prone Positioning and Nitric Oxide in Adult COVID-19 Patients With ARDS by Electrical Impedance Tomography

We aims to investigate the effects of prone positioning and nitric oxide inhalation in adult patients who is diagnosed with COVID-19 associated acute respiratory distress syndrome by electrical impedance tomography.

The investigators aim to investigate the effects of prone positioning and nitric oxide inhalation in adult patients who is diagnosed with COVID-19 associated acute respiratory distress syndrome by electrical impedance tomography (EIT).

The EIT assessment is performed in patients ventilated in supine position, supine position with NO inhalation for 1 hour, prone position for 1 hour, prone position for 2 hours with NO inhalation for 1 hour, prone position for 3 hours, prone position for 16 hours, re-supine position for 3 hours. Arterial blood gas (ABG) analysis results, ventilator parameters and hemodynamic parameters are also recorded at each time point.

Inclusion Criteria:

• adult patients who have COVID-19-associated acute respiratory distress syndrome

Exclusion Criteria:

• patients who refuse to participate in the study; unable to use EIT, such as open-chest surgery with chest tube placement; have contraindication for prone positioning, including pregnant, post-abdomen surgery within a week; hypercapnic respiratory failure.