Despite ongoing trials of antivirals and immunomodulatory therapies against COVID-19, the treatment of moderate/severe disease is mainly supportive, including oxygen therapy and invasive mechanical ventilation when impending respiratory failure is established. Moreover, the associated mortality among mechanically intubated patients is overwhelmingly high. Prone position relieves the dependent lung regions from the compressive forces of the mediastinum's weight, leading to homogenization of the gas:tissue ratio between ventral and dorsal lung regions. According to a few case series, and observational non-randomized studies with small sample sizes, there is a consistent improvement in oxygenation in COVID-19 patients during prone positioning, however there are no clinical evidence that this improvement is associated with a decrease in the risk of invasive mechanical ventilation. Considering that prone positioning is a low cost, low risk and widely available therapy, more high quality evidence is needed, to determine if the benefits of prone positioning in awake patients also include a lower requirement of mechanical ventilation.
Besides protective ventilation with low tidal volumes, prone positioning is a proven intervention to decrease mortality in mechanically ventilated patients with moderate-severe acute respiratory distress syndrome. However, the evidence of this strategy in awake non-intubated patients is scarce. The investigators will perform a randomized controlled trial to define if prone positioning can reduce the requirement of mechanical ventilation.