Objectives: We compared the efficacy of the
standard nasal cannula and the demand oxygen delivery system (DODS)
during sleep in patients with COPD.
patients with moderate or severe COPD were included in the study.
Methods: Four consecutive polysomnographic recordings were
performed under the following conditions: DODS powered by compressed
air (night 1 [N1]); oxygen delivered with a nasal cannula alone
(night 2 [N2]); oxygen delivered through a DODS (night 3 [N3]); and
oxygen delivered with nasal cannula alone (night 4 [N4]). Oxygen flow
rates with and without DODS were adjusted the day before the first
night so that the resulting transcutaneous arterial oxygen saturation
(Sao2) was ≥ 95%. The following parameters
were evaluated each night: apnea-hypopnea index, nocturnal
Sao2, total oxygen saving, and several
Results: The oxygen
saving with the DODS was, on average, 60%. All parameters obtained
during N2 and N4 (oxygen alone) were identical. The percentage of total
recording time spent at Sao2 ≥ 95% was
comparable between N2 ([mean ± SD]; 69 ± 32%) and N3
(61 ± 31%) (difference is not significant [NS]), as was the time
spent at Sao2 between 90% and 95% (N2,
29.8 ± 31%; N3, 35.9 ± 27%; NS) and < 90% (N2,
0.75 ± 2.6%; N3, 2.5 ± 8.6%; NS). Although the mean response
time was not significantly different between N2 and N3, two patients
experienced a substantial increase in response time with an
Sao2 < 90% on the DODS. The DODS device did
not induce any difference in the percentage of time spent in rapid eye
movement (REM) sleep (N2, 12.3 ± 8.7%; N3, 16.4 ± 7.8%; NS) or
non-REM sleep (N2, 87.7 ± 8.7%; N3, 83.7 ± 7.9%; NS). Non-REM
distribution in stage 1–2 sleep and in stage 3–4 sleep was comparable
between N2 and N3. Similarly, no difference was observed for the
sleep efficiency index (N2, 71 ± 15%; N3, 69.6 ± 14%; NS).
Differences between sleep onset latency times were NS.
Conclusions: In a majority of moderate to severe COPD
patients, the use of a DODS device does not induce any significant
alteration of nocturnal neurophysiologic and ventilatory profiles.
However, the presence of nocturnal desaturation in a few patients
justifies the need to systematically perform a ventilatory polygraphic
recording when prescribing a DODS device.