EvitaXL

Response times longer than 15 seconds may only occur if the
minimum ventilation with a very low frequency f is set to correspondingly
low values.
In this case, EvitaXL triggers an apnoea alarm, which is cancelled
again as soon as the mandatory ventilation strokes have
been applied. If the set cycle time (1/f) is longer than the
TApnoea W alarm limit and if there is no spontaneous breathing
between the mandatory ventilation strokes, the apnoea alarm
will be triggered regularly.
Example: f = 3/min = cycle time (1/f) = 20 seconds
TApnoea W = 15 seconds
This system is designed to prevent mandatory ventilation being
prematurely triggered in the event of irregular spontaneous
breathing, whilst at the same time giving an alarm for any long
period of minimal ventilation.
BIPAP
Biphasic Positive Airway Pressure
The BIPAP ventilation mode is a pressure/time-cycled ventilation
mode in which the patient can always breathe spontaneously.
BIPAP is therefore often described as a time-cycled
alternation between two CPAP levels.*
The time-cycled change of pressure gives controlled ventilation,
which corresponds to pressure-controlled ventilation
PCV. However, the constant option of spontaneous breathing
allows the transition from controlled breathing to independent
spontaneous breathing to take place smoothly via the weaning
phase, without requiring any change the ventilation mode. To
adapt easily to the patient's spontaneous breathing pattern,
the change-over from expiratory pressure level to inspiratory
pressure level, and also the change-over from inspiratory pressure
level to expiratory pressure level, are synchronised with
the patient's spontaneous breathing.
The frequency of the change-over is kept constant, even when
synchronisation occurs via a "trigger window" with fixed time
constant.
The "trigger window" is 5 seconds long in adult mode and
1.5 seconds long in paediatric mode. For expiration times
shorter than 5 seconds or 1.5 seconds, the "trigger window"
covers the entire expiration time. At Pinsp level, the "trigger window"
is 1/4 ·Tinsp seconds long.
As recent clinical research** has shown, this smooth adaptation
to the patient's spontaneous breathing requires less sedation,
so that the patient returns to spontaneous breathing more
rapidly.
* Bibliography [3], [4], [7], [11], [12], page 235
** Bibliography [8], page 235
Ventilation Modes
MMV
BIPAP
Instructions for Use EvitaXL 213