Dräger Babylog 8000 plus Operating Instructions Manual page 132

Theory of Operation
Ventilation Modes
Ventilation Modes
Continuous Positive Airway Pressure
(CPAP)
Babylog 8000 plus keeps airway pressure at the
PEEP/CPAP level. The patient may breathe sponta-
neously at all times. Inspiratory flow should be set
significantly higher than what the patient needs for
spontaneous breathing in order to avoid fluctuations of
airway pressure or increased work of breathing.
Continuous Mandatory Ventilation
(CMV)
Mandatory ventilation with continuous flow regardless of
spontaneous breathing. Mandatory breaths are timed
according to set values for T
Between mandatory breaths, Babylog 8000 plus keeps
airway pressure at the PEEP/CPAP level. The patient
may breathe spontaneously at all times.
The settings for * , T , and P
insp in
breath: The continuous flow determines the pressure
rise, T the duration of the inspiration, and P
in
inspiratory pressure. When the pressure waveform
reaches P , a pressure plateau will be formed. When
insp
P is not reached, the pressure waveform will exhibit a
insp
peak.
The pressure waveform pattern determines the factors
for tidal volume V . In two cases this relationship is
T
straightforward.
Pattern 1, long plateau:
If the pressure plateau is long enough to allow flow to
drop to zero by the end of inspiration, lung pressure will
have reached equilibrium with airway pressure. Then
airway pressure, i.e. the difference between P
PEEP, will determine tidal volume as
- PEEP) . C
V = (P
T insp rs
where C is the compliance of the respiratory system.
rs
132
and T .
in ex
shape a mandatory
insp
limits
insp
and
insp