Treatment of ventilatory failure in the Prader-Willi syndrome.

Hypercapnic respiratory failure is a common cause of death in the Prader-Willi syndrome. Its relationship to sleep-disordered breathing has not been established and there are no reports of its successful treatment. We have retrospectively reviewed the records of four patients with the syndrome, who developed ventilatory failure. Daytime arterial blood gas tensions and overnight oximetry traces before and during treatment were compared. Each patient had severe sleep-disordered breathing in association with daytime ventilatory failure. The median overnight mean arterial oxygen saturation (Sa,O2) was 82% and the median minimum was only 41.5%. Initial treatment was with nasal intermittent positive pressure ventilation, and in each case the daytime arterial blood gas tensions were normalized. The patients were maintained on nasal continuous positive airway pressure at night after discharge. Compliance has been good, and at last follow-up (after a median of 4.8 yrs) the daytime arterial gas tensions remained normal, while the median overnight mean arterial oxygen saturation was 95.5% and the median minimum was 84.5%. This study of patients with the Prader-Willi syndrome shows that daytime ventilatory failure is associated with sleep-disordered breathing. It can be reversed with nocturnal noninvasive ventilation and maintenance treatment with continuous positive airway pressure is well tolerated, with no deterioration in respiratory parameters.