Table of Contents
Advertisement
An inspiratory time T
set to a value shorter than the
insp
time required to fill the lungs can be recognized in the
flow waveform: the flow at the end of inspiration will not
have dropped to zero. The decision whether or not to
extend inspiratory time T
insp
pressure must then be based on the current patient
condition.
The effect described can also develop in the course of
ventilation, e.g. due to a buildup of secretions. In this
situation, pressure is limited by the alarm limit »P
The pressure rise stops 5 cmH
»P
W «. A »Volume not constant« alarm will only be
aw
generated when the set tidal volume V
applied.
The start of a mandatory inspiration can be synchronized
with a patient's own efforts using the adjustable flow
trigger. Only while in CMV mode can the flow trigger be
fully switched off (CMV Assist -> CMV).
The steepness of the pressure rise from PEEP level to
the inspiration level can be even more closely adapted to
the needs of the patient in SIMV and MMV modes by
adjusting pressure rise time »Slope«.
Initial ventilator response with AutoFlow
When switching on AutoFlow, Evita 2 dura applies a
volume controlled ventilator breath with subsequent
inspiratory pause.
The plateau pressure P
plat
breath serves as start-up value for inspiratory pressure
with AutoFlow.
in order to lower peak
W «.
aw
O below the alarm limit
2
is not longer
T
calculated for this ventilator
Description of Ventilation Modes
Volume Controlled Ventilation with PLV and AutoFlow
P
aw
P
= f (V
insp
PEEP
T
T
insp
e
1
f
Flow
V
T
without spontaneous
breathing
P
>
aw
,C)
T
with spontaneous
breathing
t
t
21
Advertisement
Table of Contents
