We describe five patients with severe nocturnal cough and daytime somn
olence in whom the coughing attacks are triggered by assuming the supi
ne body position. Quantity and quality of the nocturnal cough were eva
luated in the sleep laboratory with and, without nasal continuous posi
tive airway pressure (N-CPAP). Air flow characteristics were assessed
using flow volume and airway resistance loops. Airway anatomy was eval
uated bronchoscopically. In all five patients, the cough had a barking
quality. Flow-volume loops sho,wed an expiratory collapse phenomenon
in two of the patients. Endoscopically, all five patients had signs of
airway collapse. Ah patients had difficulty falling asleep because of
coughing and were awakened by it frequently. Sleep times ranged from
2.5 to 4.5 h per night. With N-CPAP pressures ranging from 5 to 13 cm
H2O, all five patients had clinically significant improvement in their
symptoms. Their sleep times increased to a range of 5 to 7.5 h per ni
ght and the daytime somnolence markedly improved or resolved. All five
patients requested a N-CPAP unit for home use. We conclude that a cou
gh that is predominantly associated with or exacerbated by the supine
body position may be treated effectively with N-CPAP.