NORTH AMERICAN DRÄGER Auto Flow Brochures
Auto Flow
®
20 Questions – 20 Answers
Joseph Fitzgerald
Important Notice:
Medical knowledge changes
constantly as a result of new
research and clinical experience.
The author of this introductory
guide has made every effort to
ensure that the information
given is completely up to date,
particularly as regards applications
and mode of operation. However,
responsibility for all clinical
measures must remain with the
reader.
Written by:
Dräger Medizintechnik GmbH
Joseph Fitzgerald
Moislinger Allee 53/55
23542 Lübeck
Germany
All rights, in particular those of
duplication and distribution,
are reserved by Dräger Medizintechnik GmbH. No part of this
work may be reproduced or stored
in any form using mechanical,
electronic or photographic means,
without the written permission of
Dräger Medizintechnik GmbH.
ISBN 3-926762-40-3
Auto Flow
®
20 Questions – 20 Answers
Joseph Fitzgerald
20 Questions – 20 Answers using AutoFlow
®
4
Contents
■ What is AutoFlow
®
? 6
■ Is AutoFlow
®
a new Ventilator Mode? 7
■ When would you use AutoFlow
®
? 8
■ How does AutoFlow
®
compare to BIPAP 9
■ How is AutoFlow
®
combined with other modes
such as IPPV?
10
■ How does AutoFlow
®
work with SIMV? 11
■ How does AutoFlow
®
work with MMV? 12
■ How does ventilation with AutoFlow
®
compare
with volume controlled ventilation?
14
■ How does ventilation with AutoFlow
®
compare
to pressure regulated modes?
15
■ What type of lung diseases is AutoFlow
®
suitable for? 16
■ Are there situations where it is not indicated? 17
■ What has to be considered when switching from
conventional modes to AutoFlow
®
? 18
■ How do you set up AutoFlow
®
? 19
■ What monitoring parameters are important to
observe when using AutoFlow
®
? 20
20 Questions – 20 Answers using AutoFlow
®
5
■ What are the advantages to observe when
using AutoFlow
®
? 22
■ What would be the subsequent management
of the patient?
23
■ What are the safeguards against
hypo/hyperinflation?
24
■ How does AutoFlow
®
interact with inverse ratio
ventilation?
25
■ How can mechanical ventilation and
spontaneous breathing be mixed in one mode?
26
■ What is the technology behind this latest
advance in therapy?
28
Explanatory note: In some regions of the world IPPV
mode of ventilation is referred to as CMV and
Assist/CMV. The mode BIPAP is referred to as PCV+ in
the USA and Canada. BIPAP* is trademark used under
licence. AutoFlow
®
is registered as a trademark of
Dräger Medizintechnik GmbH.
20 Questions – 20 Answers using AutoFlow
®
6
1. What is AutoFlow®?
This is a new advance in volume controlled modes
of mechanical ventilation where the ventilator
automatically regulates inspiratory flow. This auto
regulation is in accordance with the set V
T
and
current lung compliance.
The set V
T
is always given at minimum possible
pressure and spontaneous breathing is possible (open
valves) through the whole Inspiratory and Expiratory
phases of the mechanical ventilatory cycle.
A decelerating flow pattern reduces Peak pressures
and as lung compliance changes further they are
recognised and responded to.
Flow
V
Volume Controlled Switch-on AutoFlow
®
T
V
T
A decelerating flow pattern
reduces Peak pressures
20 Questions – 20 Answers using AutoFlow
®
7
2. Is AutoFlow
®
a new Ventilator Mode?
It is a new addition to all volume controlled modes on
the Evita 4 and Evita 2 dura ventilator. It is not a mode
independently selected in itself. It could be compared
to the way one function enhances another such as
flow trigger enhances pressure support.
It is intended to simplify strategies in mechanical
volume controlled ventilation by offering more patient
benefits with a wider therapy range and with less
parameters to adjust.
20 Questions – 20 Answers using AutoFlow
®
8
3. When would you use AutoFlow®?
There are very few exceptions to using AutoFlow®in
all volume oriented modes where it is available. In
general we can divide its use into two areas, that of
the type of ventilatory strategy we want to apply and
that of the type of patient that it is particularly suited
to. In the first case in volume strategy ventilation
where we want to reduce high airway pressures and
capitalise on spontaneous breathing with reduced use
of sedation and muscle relaxants. The decelerating
flow and the regulated inspiratory and expiratory
valves provide a response to every inhalatory and
exhalatory effort of the patient. This feels like breathing
through an open system.
In other strategies we may want to use inverse ratio
timings. The occlusion of the expiratory valve for such
lengths of time can produce risk of barotrauma for a
patient who becomes awake and starts breathing.
With an open breathing system this risk is greatly
reduced.
In terms of patient types, there are those with quite
variable compliance levels after surgery who require
careful manipulation of inspiratory pressure and
volume to prevent barotrauma and hyperinflation.
AutoFlow
®
continually adjusts the pressures as
compliance changes to ensure volume delivery at the
lowest possible pressures.
Finally, as a smooth weaning strategy we want the
first efforts by the patient to be responded to in all
phases of the mandatory stroke unlike conventional
modes of SIMV where there are closed phases in the
cycle. The fixed set V
T
delivery of SIMV is also addressed
for Bronchospasm patients with air hunger as all
demands for flow and volume are responded to by the
ventilator.
20 Questions – 20 Answers using AutoFlow
®
9
4. How does AutoFlow
®
compare to BIPAP?
BIPAP has been established for a number of years as
a real advance in pressure controlled ventilation
strategies. Pressures are regulated at a specific value
and pressure peaks are eliminated and together with
time synchronisation the patient is able to breathe
spontaneously at any stage. Many of these features are
now transferred across into the volume controlled
modes as the benefits of this therapy have become
more extensively accepted. The prime parameter
setting in BIPAP is inspiratory pressure (Pinsp) and
tidal volume (V
T
) is variable, the prime adjustment in
AutoFlow
®
is VTand the pressure is the variable,
depending on the compliance.
Many benefits of BIPAP
are transferred into volume
controlled modes with
AutoFlow
®
Loading...