重症の閉塞性睡眠時無呼吸を伴わない肥満低換気症候群の1例

Abstract

A 50-year-old man with severe obesity was admitted to our hospital because of exertional dyspnea. Diagnostic polysomnography (PSG) revealed it to be Obesity Hypoventilation Syndrome (OHS), where the sleep disordered breathing was predominantly sleep hypoventilation rather than severe obstructive apnea-hypopnea. Non-invasive Positive Pressure Ventilation therapy was effective for this OHS patient. To understand the pathophysiology of OHS, we should consider the OHS phenotype that is sleep hypoventilation or severe obstructive sleep apnea (OSA) the predominant OHS, since treatment strategy differs for different phenotypes. Depending on the condition of right heart failure, rostral fiuid shift might occur during sleep, which will induce OSA. Therefore, to understand the exact OHS phenotype, we have to be careful about when diagnostic PSG should be performed.