Hoffrichter 5CPD10, User Manual

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64 Chapter 5: Therapy Modes
A-S mode (auto S mode)
Main features
•
Automatic adjustment of therapy pres-
sure (IPAP and EPAP)
•
Pressure supported
•
Patient triggered
•
Flow controlled
•
Device only responds to spontaneous
breathing
•
Apnoea sound
Auto-S mode is an extension of S mode and offers the additional function of automatic
adjustment of therapy pressure (IPAP and EPAP) within certain limits. When obstructive
events are detected
1
, the expiratory and inspiratory pressure are increased evenly
2
until
the airways are almost completely open or the inpiratory pressure has reached the upper
pressure limit. In case of central events and normal breathing, however, the expiratory
and inspiratory pressure are reduced evenly
2
until the expiratory pressure has reached
the low pressure limit. For high therapy comfort, the expiratory pressure should always
be as high as necessary and as low as possible In addition, the speed of the pressure
increase can be adapted to the patient’s special needs in 5 stages.
Secondary features
•
Obstructive apnoea
•
Central apnoea
•
Hypopnoea
•
Snoring
•
Normal breathing
20
10
0
IPAP
EPAP
t
p (hPa)
Ⓐ Ⓐ
Ⓐ
Ⓐ Ⓐ
1
2
3
4
Upper
pressure limit
Lower
pessure limit
Upper pressure limit = 25 hPa Low pressure limit = 4 hPa IPAP = 20 hPa EPAP = 8 hPa
Obstructive apnoea detected

Pressure increase
Central apnoea  Pressure decrease
Spontaneous breathing  Pressure decrease
Obstructive apnoea detected  Pressure increase
Ⓐ
Pressure controlled supported ventilation

spontaneous breathing
Figure 29: Diagram of A-S mode
1 Detection via forced oscillation technique (FOT)
2 Differential pressure remains constant