S A N T È • LÖW E N S T E I N S L E E P T H E R A PY D E V I C E S
Appendix 8 Pgs. 3-4
SLEEP MEDICINE | V. ISETTA ET AL.
a)
Normal breathing
0.5 0.0 –0.5
Flow L·s –1
80 40 0
Resistance
10 s
cmH 2 O·L·s
–1
12
b)
Prolonged flow limitation
0.5 0.0 –0.5
Flow L·s –1
80 40 0
10 s
Resistance
cmH 2 O·L·s
–1
10
c) Flow L·s –1
Mild hypopnoea
0.5 0.0 –0.5
80 40 0
10 s
Resistance
cmH 2 O·L·s
–1
7
Severe hypopnoea
d) Flow L·s –1
0.5 0.0 –0.5
80 40 0
10 s
Resistance
cmH 2 O·L·s
–1
FIGURE 1 Breathing patterns reproduced by the simulated obstructive sleep apnoea patient depending on the continuous positive airway pressure (CPAP) applied by automatic CPAP devices: a) normal breathing; b) prolonged flow limitation; c) mild hypopnoea; d) severe hypopnoea; e) apnoea with obstruction. Reproduced from [23] with permission from the publisher.
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e)
Apnoea with obstruction
0.5 0.0 –0.5
Flow L·s –1
80 40 0
10 s
Resistance
cmH 2 O·L·s
–1
0
and G. Breathing normalisation (defined as the avoidance of any obstructive event: apnoea, hypopnoea or flow limitation) was only achieved with the A1, A2 and C devices. Figure 2 shows examples of the first 30 min of device response for one device that achieved breathing normalisation (A2) and another that was unable to overcome obstructive events (B).
TABLE 1 Reponses of automatic continuous positive airway pressure (APAP) devices to obstructive sleep apnoea simulated by the bench test
APAP device
P max cmH 2 O
t max min
P mean cmH 2 O
Residual AHI events per h
Breathing normalisation
A1 A2
17.9, 17.8 15.4, 15.6 10.5, 10.5 13.4, 13.9 10.7, 10.7 10.4, 10.4 11.9, 12.1 10.5, 11.0
22.4, 19.0 40.3, 57.7
14.6, 14.6 13.4, 13.5
2.0, 2.0 2.0, 1.5
Yes , yes Yes, yes
B C D E F G
130.6, 121.3 28.0, 44.1 75.1, 103.7
6.7, 7.9
74.5, 71.0
No, no
12.4, 12.2
3.0, 3.0
Yes, yes
9.7, 9.7
26.5, 32.5
No, no No, no No, no No, no
20.7, 18.9 34.4, 36.0 32.2, 83.2
10.2, 10.2 10.1, 10.1
3.5, 2.5 11.5, 13 33, 26.5
9.9, 9.9
The two values for each variable correspond to the results obtained in the two test repetitions in each device. P max : maximum positive airway pressure applied; t max : time to reach P max ±0.3 cmH 2 O; P mean : mean positive airway pressure; AHI: apnoea – hypopnoea index; A1: AirSense 10, standard setting; A2: AirSense 10, response setting; B: Dreamstar; C: Icon; D: Resmart; E: Somnobalance; F: System One; G: XT-Auto.
ERJ Open Res 2015; 1: 00031 ‐ 2015 | DOI: 10.1183/23120541.00031-2015
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