Table of Contents
Advertisement
AV-E ANESTHESIA VENTILATOR (continued)
Inspiratory Flow Control
The rotary knob marked "INSPIRATORY
FLOW" controls the flow rate of gas into
the bellows chamber, and the inspiratory
flow rate of gas into the patient's lungs.
However, due to such variables as total
lung compliance, equipment compliance,
and airway resistance, the inspiratory flow
control
cannot
be
numerical values. Instead, the gauge to the
left of the control knob is labeled with
three zones, "LOW," "MEDIUM," and
"HIGH" (Figure 13).
The flow setting is to be adjusted so that
the bellows is fully compressed at the end
of the inspiratory phase. In order to deliver
the desired, preset tidal volume, adjust the
inspiratory flow control so that the bellows
corrugations make contact with each other
but are not deformed at the end of the
inspiratory phase.
The inspiratory flow control can be used to
create an inspiratory plateau at the end of
the inspiratory cycle. It also affects the
peak inspiratory pressure that can be
developed within the patient breathing
system.
Always check the pressure
indicated by the breathing system pressure
gauge and waveform when adjusting the
inspiratory flow control.
22
calibrated
with
RETURN TO CD-ROM TABLE OF CONTENTS
Ventilator Relief Valve
During
automatic
manual/automatic selector valve isolates
the absorber's APL (adjustable pressure
limiting) valve from the breathing system.
To
compensate
for
introduction of fresh gas into the breathing
system, the ventilator incorporates a relief
valve
mounted
behind
chamber.
The ventilator relief valve remains closed
until the end of expiration so that the
ascending bellows can expand upward and
refill. When the bellows is completely
filled, any excess gas in the system is
released by the ventilator relief valve to
the
scavenging
system.
ascending bellows, the force needed to
overcome gravity acting on the bellows
causes a PEEP within the breathing
system, in this case approximately 2 cm
H
O.
2
Bellows PEEP Valve (Optional)
An optional ventilator PEEP valve mounts
beneath the bellows. (An optional absorber-
mounted PEEP valve is also available.)
The
operator
can
approximately 2 to 15 cm H
PEEP valve control knob. Clockwise
rotation of the knob increases PEEP and
counterclockwise rotation decreases PEEP.
The breathing system pressure gauge and
the breathing pressure monitor indicate
the amount of PEEP at the end of
exhalation. For details, see the Bellows
PEEP Valve Instruction Manual.
ventilation,
the
the
continuous
the
bellows
As
in
any
set
a
PEEP
of
O with the
2
Advertisement
Table of Contents
