Effect of prone position on apnea severity in obstructive sleep apnea

We describe a patient with obstructive sleep apnea (OSA) whose apnea-hypopnea index (AHI) improved remarkably in the prone position accompanied by an improved sleep quality, despite a higher AHI in the supine position and even in the lateral position. Magnetic resonance imaging revealed the most dilated upper airway in the prone position, which suggests the role of anatomical narrowing of the upper airway as an important component in the pathophysiology of positional apnea patients. Further studies are needed to determine the therapeutic efficacy of a prone sleeping position in patients with OSA.