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CPAP mode, an inspiratory effort triggers the flow of a volume of gas equal
to inspiratory time X flow rate. However, in this mode the high pressure is
not applied intermittently to the exhalation valve. Only the PEEP/CPAP
control is operative. The PEEP/CPAP control may be turned fully clockwise
thus applying zero pressure to the exhalation valve. In this way the ventilator
may be used to administer, on demand, gas of a preset oxygen
concentration at ambient pressure. In both the SIMV and CPAP modes
there may be a momentary fluctuation of a few cmH
2
O pressure depending
on the flow rate, inspiratory time, system compliance and gauge response.
Note that in this mode, the expiratory time should be turned to maximum
(fully clockwise) and the NORMAL/SIMV selector should be in the SIMV
position. This will prevent false cycling and help to reduce gas consumption.
It is also advisable, for added safety, the maximum pressure control be
turned off (fully clockwise) when using the CPAP mode.
5. Manual
Mode
The manual control can be used for hyperventilating before suctioning,
sighing the patient or synchronizing with chest compressions for
cardiopulmonary resuscitation.
The manual button is inoperative until the CYCLE/CPAP-MANUAL selector is
switched to the CPAP-MANUAL position. The inspiration time is set with the
inspiratory time control. The manual button should be depressed long
enough on each cycle to set the inspiratory timer and then released. The
inspiratory period will then last as long as the time set with the inspiratory
time control. The tidal volume is then equal to the inspiratory time X flow rate
(volume limited).
If the manual button is held in for a time greater than the preset inspiratory
time, then inspiration will last during the entire time that the manual button is
depressed. In this case the volume delivered is unknown. The pressure
gauge may be observed as an indicator of degree or ventilation. By using
the PEEP/CPAP control it is possible to ventilate manually with PEEP. The
MAX. PRESSURE control may also be used in manual mode to pressure
limit each breath.
B. CONTROLS, INDICATORS AND CONNECTIONS
1. Controls
a. CYCLE/CPAP-MANUAL
Switch
Selects non-cycling (CPAP) or time-cycled (cycle) modes or
operation.
b. Inspiratory
Time
Sets inspiratory time in time cycled modes. Calibrated from 0.4 to 2.0
sec.
c. Expiratory
Time
Sets expiratory time in time-cycle modes. Calibrated from 0.5 to 4
Summary of Contents for 2005IC
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