Dräger Fabius, Instructions For Use Manual, Page: 67 / 232

Instructions for Use Fabius MRI SW 3.n
67
Assembly
Instructions for Use of Bacterial Filters, Endot-
racheal Tubes, Y-pieces, Breathing Hoses,
Soda Lime and other Breathing System Acces-
sories
With increased breathing resistance, more effort is
required on the part of the patient during spontane-
ous breathing. With volume-controlled ventilation,
increased breathing resistance during inspiration
has a negligible effect on the administered volume.
The peak pressure is however increased during
constant plateau pressure. Therefore, during the
expiration phase, the time constant (RC) increases.
When expiratory times are too short, this may result
in the lungs not fully emptying, leading to dynamic
lung air trapping. With pressure-controlled ventila-
tion, increased airway resistances may result in
reduced inspiratory or expiratory volumes.
Before performing the self-test on the device used,
the accessory to be used for the application must
first be connected. Expander hoses must be pulled
out to the appropriate length in order for compli-
ance to be accurately determined and, in the case
of volume-controlled ventilation, for the correct tidal
volume to be administered.
When using coaxial hoses, leaks between the inner
and outer hoses cannot be detected during the self-
test/leak test.
Resistance summation of the breathing system
and connected accessories
In the chapter Technical Data, the inspiratory and
expiratory breathing resistance of the breathing
system is given without considering the breathing
hoses. This allows for the determination of the
resistance at the patient using different hose sets
and/or filters.
To calculate the Resistance (R) use the following
formula:
R
Expiration
=
R
Breathingsystem_exp
+ R
ExpHose
+ R
ExpFilter
R
Inspiration
=
R
Breathingsystem_insp
+ R
InspHose
+ R
BagHose
+
R
InspFilter
Ensure that only accessory resistance data is used
for system resistance calculation using the peak
flow applicable for the accessory and patient cate-
gory, e.g. for adults resistance data at 60 L/min, for
children at 30 L/min, and for neonates at 5 L/min.
If a filter is used on the Y-piece, the resistance for
the inspiratory and expiratory direction must be
considered.
The standard for anesthesia breathing systems
(ISO 8835-2:2007) allows an overall resulting pres-
sure loss at 60 L/min of max. 6.0 cmH
2
O (6.0 hPa)
both inspiratory and expiratory.
z Refer to the Instructions for Use of the respec-
tive accessory.
WARNING
When using accessories in breathing systems
or configurations that deviate from standard
hose systems, the inspiratory and expiratory
breathing resistances may exceed normal
requirements (e.g., extended hoses with
lengths of 3 m (10 feet) used with MRI sys-
tems).
The user should exercise particular care and
monitoring when using such configurations.
CAUTION
The reusable microbes filter 654 ST isoclic (part
number 6733895) must be connected directly at
the cosy side of the breathing tubes to avoid risk
of image artifacts.