Autoflow - Dräger Oxylog 3000 plus Instructions For Use Manual

Principles of Operation
During the lower pressure level phase,
spontaneous breathing can be assisted by
Pressure Support PS. The steepness of the
Δ
pressure increase to
controlled by the Slope setting.

AutoFlow

Paw
Pinsp = f (Vt, C)
PEEP
Tinsp Te
1
RR
Flow
Vt
without spontaneous breathing with spontaneous breathing
AutoFlow (AF) delivers the set tidal volume VT
using a decelerating flow pattern to achieve the
lowest peak airway pressure possible. The
Oxylog 3000 plus determines the pressure
required to deliver the set tidal volume VT based on
lung characteristics such as resistance and compli-
ance relationships, and the patient's spontaneous
breathing demand.
When the patient inhales, the Oxylog 3000 plus
delivers additional inspiratory flow.
The maximum inspiratory pressure in AutoFlow is
limited to:
– 5 mbar below Pmax.
The patient's current condition must be considered
when setting Pmax, to avoid the possibility of
causing harm if the airway pressure increases.
Always set Pmax carefully in order to limit the
airway pressure in case of a reduced compliance.
162
Psupp above PEEP is also
Paw
Weaning from controlled ventilation to fully
spontaneous breathing is achieved by a gradual
reduction of inspiratory pressure Pinsp and/or the
respiratory rate RR.
If the set tidal volume VT cannot be achieved and
the maximum inspiratory pressure is reached, the
alarm VT low, pressure limit is generated.
The minimum inspiratory pressure in AutoFlow is
limited to:
t
– 5 mbar above PEEP for non-triggered breaths;
– 0.1 mbar above PEEP for triggered breaths.
Typically, the selected inspiratory time Ti is much
longer than the lung filling time. The inspiratory
t
pressure Pinsp corresponds to the minimum value
calculated from the tidal volume and compliance C
of the lungs. The inspiratory flow is automatically
controlled, so that there is no pressure peak
caused by the resistances of the tube and the air-
ways. With AutoFlow, the inspiratory flow will adjust
a maximum of 3 mbar breath to breath.
If the tidal volume VT is reached (inspiratory
flow = 0), before the inspiratory time Ti has fully
elapsed, the Oxylog 3000 plus ensures that the
patient can breathe during the remaining inspira-
tory time.
If the patient breathes during mandatory inspira-
tion, the inspiratory pressure remains constant for
this breath. Only the inspiratory and the expiratory
flow are adapted to the patient's demand. The
applied tidal volume may differ from the set tidal
volume VT for spontaneous generated breaths, but
on average a constant tidal volume is maintained.
The Oxylog 3000 plus terminates an AutoFlow
breath if the tidal volume delivered to the patient is
30 % greater than the set tidal volume VT.
Instructions for Use Oxylog 3000 plus SW 1.n