A Physiological Study to Assess Awake Prone Positioning and Respiratory Support in Healthy Volunteers

A Physiological Study to Assess the Effects of Awake Prone Positioning in Healthy Volunteers Under Different Respiratory Support: A Randomized Crossover Study

Awake prone positioning (APP) has been proven to reduce the intubation rate for patients with COVID-19-induced hypoxemic respiratory failure. Our recent meta-analysis found APP was only effective for patients who were treated by high-flow nasal cannula (HFNC), not for patients using conventional oxygen therapy (COT).In a recent multicenter RCT, Perkins and colleagues reported that continuous positive airway pressure (CPAP) was superior to HFNC and conventional oxygen therapy in reducing intubation rate. Thus, it is essential to evaluate the physiological mechanism of APP under different respiratory supports, such as COT, HFNC, or CPAP.

We hypothesize that HFNC or CPAP is more effective when combined with APP than COT combined with APP. Electrical impedance tomography (EIT imaging) has been broadly utilized to assess patient ventilation homogeneity and respiratory volume monitor (RVM) has been used to evaluate patient's tidal volumes breath-by-breath. In this study, 20 healthy volunteers will use different respiratory support devices (HFNC, CPAP, and COT) in different settings and their combinations withAPP in a random sequence, assessed by EIT and RVM.

Awake prone positioning (APP) has been proven to reduce the intubation rate for patients with COVID-19-induced hypoxemic respiratory failure. Our recent meta-analysis found APP was only effective for patients who were treated by high-flow nasal cannula (HFNC), not for patients using conventional oxygen therapy (COT).In a recent multicenter RCT, Perkins and colleagues reported that continuous positive airway pressure (CPAP) was superior to HFNC and conventional oxygen therapy in reducing intubation rate. Thus, it is essential to evaluate the physiological mechanism of APP under different respiratory supports, such as COT, HFNC, or CPAP.

Inclusion Criteria:

healthy adults aged between 21 to 65 years

Exclusion Criteria:

• Tested COVID positive within 21 days, or has any of the following symptoms in the last 21 days: sore throat, cough, chills, body aches for unknown reasons, shortness of breath for unknown reasons, loss of smell, loss of taste, fever at or greater than 100 degrees Fahrenheit.
• Currently have the following symptoms: sore throat, fever, coughing, shortness of breath, loss of smell or taste
• Non-English speaking
• Has any of the following diseases: asthma, chronic obstructive pulmonary disease, Uncontrolled Diabetes, hypertension, or untreated thyroid disease
• and spinal cord injury.
• Claustrophobia
• Pregnancy
• Pacemaker (EIT contraindication)
• face or chest skin injury that could not use a facemask or the electrode belt
• could not tolerate prone positioning for one hour