[Obstructive sleep apnea syndrome associated with superior vena cava syndrome]

A 43-year-old man was admitted suffering from dyspnea on exertion and edema of the neck and face. Chest X-ray film and CT scan revealed a mediastinal tumor and a right pleural effusion. A biopsy of the tumor revealed poorly differentiated carcinoma. Severe snoring at night and excessive daytime sleepiness were noticed after admission. Nocturnal oxygen desaturation was documented with a pulse oximeter, and obstructive sleep apnea syndrome was diagnosed on the basis of results of respiratory inductive plethysmography. The severity of snoring and oxygen desaturation during sleep correlated well with the progression of facial swelling. Combination chemotherapy (carboplatin 300 mg/m2 day 1, vindesine sulfate 3 mg/m2 day 1 and 8) was started but no improvement was seen. An expandable metallic stent was inserted into the stenotic vena cava, and the facial swelling, snoring, and oxygen desaturation during sleep were promptly relieved. In this case, obstructive sleep apnea was caused by edema and vascular congestion in the upper airway, and by the decrease in pharyngeal inspiratory muscle function caused by superior vena cava syndrome.