What does "prone positioning" do for patients with ARDS?

Prone positioning plays a significant role in the management of patients with Acute Respiratory Distress Syndrome (ARDS) primarily because it improves oxygenation by redistributing lung perfusion and ventilation. When patients with ARDS are placed in a prone position, the mechanics of lung function change, allowing for better ventilation of the dorsal regions of the lungs, which are often more affected in ARDS. This repositioning can enhance the drainage of secretions and improve ventilation-perfusion mismatch, ultimately leading to better oxygen exchange and improved arterial oxygen levels.

In ARDS, the recruitment of collapsed or poorly ventilated lung units is critical, and prone positioning can facilitate this recruitment, helping to ensure that more areas of the lung are participating in gas exchange. The redistribution of blood flow to better ventilated areas can improve the overall oxygenation status of the patient, which is essential in the management of ARDS.

While other factors, such as reducing pressure sores and facilitating airway clearance, are important considerations in critically ill patients, they do not directly address the primary benefit of prone positioning in terms of enhancing oxygenation in ARDS. Therefore, the improvement of oxygenation through better ventilation and perfusion is the most relevant and significant effect of prone positioning in these patients.