Abstract
Introduction: PSG helps elucidate the nature of sleep disturbance and daytime somnolence (SD-DS) but does not include the objective measurement of wheeze (Wz) or cough (C). Nocturnal Wz and C are important features of asthma and other lung diseases and have been shown to disturb sleep. Awareness of nocturnal Wz is low and often unreliable. We hypothesized that a proportion of patients referred to a sleep laboratory because of SD-DS might be suffering from nocturnal Wz or C.
Methods: 69 unselected subjects (20 – 73 yo) referred to a sleep laboratory for PSG complaining of SD-DS participated. No attempt was made to select patients with asthma or chronic cough. PSG by standard methods and ARM (Pulmotrack, KarmelSonix, Haifa, Israel) were adequate for all but 3 patients (5%). The analysis was done minute by minute throughout the record where WheezeRATE (Wz%) defined as% of duty cycle occupied by Wz and CoughCOUNT (CC) were measured. The present study concerns the detection of nocturnal Wz and C by ARM without reference to the PSG data.
Results: The duration of the overnight ARM in the 66 subjects was 65 - 478 min (median 439 min). Wz-minutes, defined as the number of minutes with a Wz% >5% and C-minutes, the number of minutes with CC=>1 were determined. In 16/66 (24%) of patients Wz-minutes occupied more than 3% of the recording and in 7/66 (10.6%) C-minutes occupied more than 2% of the recording with overlap in 3 patients who had both Wz and C.
Conclusion: With 20/66 (30%) of unselected patients referred to an adult sleep laboratory for SD-DS having nocturnal wheeze and/or cough, adding ARM to routine PSG should be considered.
- © 2011 ERS