RT Journal Article
SR Electronic
T1 Expiratory flow limitation during sleep in heavy snorers and obstructive sleep apnoea patients
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP 2116
OP 2121
DO 10.1183/09031936.96.09102116
VO 9
IS 10
A1 D Stanescu
A1 S Kostianev
A1 A Sanna
A1 G Liistro
A1 C Veriter
YR 1996
UL http://erj.ersjournals.com/content/9/10/2116.abstract
AB Inspiratory flow limitation (FL) during sleep has previously been reported both in obstructive sleep apnoea (OSA) patients and heavy snorers (HS). Recent results from this laboratory have shown the occurrence both of inspiratory and expiratory flow limitation during muscular relaxation in awake healthy subjects and OSA patients. In this study, we have investigated whether expiratory flow limitation occurs during sleep in heavy snorers and in patients with OSA. We studied four nonapnoeic, heavy snorers and five OSA patients. Airflow was measured with a pneumotachograph attached to a tight-fitting mask, and supraglottic pressure with a catheter placed at the supraglottic level. Scoring for flow limitation was achieved by visual inspection of 200 breaths recorded during sleep. About 20% of the respiratory cycles presented isolated inspiratory flow limitation. Approximately the same percentage was observed in heavy snorers and OSA patients. Isolated expiratory flow limitation was less frequently recorded. Coupled inspiratory and expiratory flow limitations were more numerous, especially in heavy snorers. We conclude that both in heavy snorers and obstructive sleep apnoea patients, inspiratory flow limitation is associated with expiratory flow limitation. This suggests that upper airway obstruction during sleep is both an inspiratory and expiratory event.