Awake prone positioning has been reported to improve oxygenation for patients with COVID-19. Awake timed and repositioning is a novel method to improve patients' compliance and prolong the prone time. This study aims to explore the impact of timed prone and repositioning on the intubation rate and prognosis of COVID-19 patients with hypoxic respiratory failure.

Patients with COVID-19 may develop severe illness characterized by progressive hypoxic respiratory failure, resulting in the need for invasive mechanical ventilation. Reducing the rate of endotracheal intubation in patients with hypoxic respiratory failure can be beneficial to the prognosis, economize iatrical resources and reduce sanitary investment. Some studies have shown that prone positioning can improve oxygenation to some extent in patients receiving invasive mechanical ventilation due to severe ARDS.

Whether awake prone positioning can reduce endotracheal intubation and mortality in COVID-19 patients with hypoxic respiratory failure is still controversial. A meta-analysis found that the awake prone positioning was safe and feasible to reduce the risk of intubation or death. However, the multicenter randomized controlled trial (RCT) conducted by Alhazzani et al pointed out that the awake prone positioning group did not significantly reduce the rate of endotracheal intubation when compared with the standard of care.

Some researchers thought the time of prone positioning is an important factor for the different results. In previous studies, the median duration of prone positioning was only 4.8-5 hours per day but some guidelines recommend the duration should be more than 8 hours. Therefore, increasing patient adherence in the awake prone positioning and extending prone positioning time are of great importance.

Awake timed prone and repositioning is a novel method proposed in recent years, which can improve patients' compliance and prolong the time of treatment. This study intends to ask whether awake timed prone and repositioning could impact the intubation rate and prognosis of unincubated patients with hypoxic respiratory failure induced by COVID-19.

Inclusion Criteria:

• Adults ≥ 18 years of age
• Awake patients without endotracheal intubation
• Suspected or confirmed infection of COVID-19
• Hypoxemia requiring oxygen supplementation ≥ 0.4 FiO2 or ≥ 5L/min via nasal cannula
• Bilateral or unilateral chest infiltrates on x-ray or HRCT
• Admitted to the ICU or an acute care unit where hemodynamic and respiratory
• Willingness to comply with the protocol and provide written informed consent

Exclusion Criteria:

• Risk of airway obstruction or even asphyxia
• Need for emergent intubation after admission
• Respiratory failure caused by cardiogenic pulmonary edema
• Unable to implement timed prone and repositioning due to any cause
• Injury or wound on the ventral body surface affecting the prone position
• Unstable fracture of cervical vertebra and spine
• Glaucoma or other sharp increases in intraocular pressure
• Intracranial hypertension caused by traumatic brain injury etc.
• Significantly high risk of pulmonary embolism
• Acute hemorrhagic disease
• Respiratory rate >40 breaths/min, with significant dyspnea
• Transcutaneous oxygen saturation can not be continuously monitored
• Hemodynamic instability requiring vasoactive drugs (systolic blood pressure <90 mmHg or mean arterial pressure <65 mmHg despite adequate volume resuscitation)
• Awareness disorder or inability to accept instructions, communication barrier with the nursing team, inability to use language or pager to call for help
• Difficulty or limitation in autonomous movement, inability to adjust the position without assistance from others
• Body mass index > 37 kg/m2