Supine versus Prone Positioning in COVID-19 Pneumonia: Comment

PRONE positioning is a simple method to improve oxygenation in ventilated patients with acute respiratory distress syndrome (ARDS).¹  Potential explanations are reduction of ventilation/perfusion mismatch, a more homogeneous distribution of transpulmonary pressure along the ventral-to-dorsal axis, and recruitment of nonaerated dorsal lung regions of the lung, with an increase in lung volume.²  Many of these mechanisms could also apply to awake patients with ARDS by COVID-19.³ 

Here, we present an image (fig. 1) from a computed tomography performed in a 71-yr-old woman with ARDS from COVID-19 in both supine and prone positioning during awake spontaneous ventilation. Arterial blood gas analysis in the supine position with high-flow nasal cannula oxygen therapy (50% concentration; flow rate, 50 l/min) showed Pao₂/fractional inspired oxygen tension (Fio₂) of 130, with an improvement in prone positioning (Pao₂/Fio₂, 238). Bilateral, multifocal, and asymmetric lung disease was present in the supine computed tomography, with a “crazy paving” pattern (ground-glass opacities associated with smooth interlobular thickening) in the upper lobes, and peripheral, heterogeneous, and ill-defined consolidations in the lower lobes. An increase in total lung volume, mainly due to a significant expansion of both lower lobes (fig. 1, black arrows), was detected in the prone position (2,749 ± 31 ml) compared to supine (2,418 ± 30 ml). This change was accompanied by a moderate decrease in the attenuation of the lesions in the lower lobes (fig. 1, blue arrows), the vast majority showing a ground glass attenuation. These findings support the hypothesis of functional lung tissue recruitment in the prone position in awake patients with ARDS by COVID-19.

The authors declare no competing interests.