Primary pulmonary hypertension with central sleep apnea - Sudden death after bilevel positive airway pressure therapy

An obese 23-year-old man with sleep-disordered breathing and primary pulmon ary hypertension (PPH) had been administered oral beraprost sodium, anticoa gulant warfarin, and home oxygen therapy, at another hospital as treatment for the PPH, but he had not experienced any symptomatic improvement. The pa tient had a body mass index of 32.4 kg/m(2), and complained of fatigue, sho rtness of breath on exertion, excessive daytime sleepiness, and snoring. Ar terial blood gas analysis showed a PaO2 and a PaCO2 of 70.9 and 31.2 mmHg, respectively. A polysomnographic study revealed central sleep apnea with an apnea-hypopnea index (AHI) of 29.7 episodes/h, The patient showed improvem ent of daytime sleepiness after starting nocturnal nasal bilevel positive a irway pressure (BiPAP) therapy for the central sleep apnea, but his pulmona ry hypertension, measured in the daytime, worsened. The patient died sudden ly while walking to the bathroom in the morning 1 month after initiation of BiPAP therapy. It is necessary to consider the possibility of sudden death when nasal BiPAP therapy is given to a PPH patient with central sleep apne a.