109
10.12.9 APRV
APRV - Continuous positive pressure ventilation and airway pressure relief
Description:
In APRV, the ventilator operates at two
pressure levels set by the operator, Superior
Pr and Inferior Pr.
The transient relief for the lower pressure level
(end of inspiration) occurs at the end of the
superior T (time set for the superior pressure
level). Likewise, restoring the superior
pressure level (beginning of inspiration) occurs
as soon as the inferior T (pressure relief time)
is exhausted.
Consequently, the respiratory rate and the
resulting I: E ratio are directly related to this
alternation between levels.
APRV has the characteristic of inversion of the
I: E ratio, where the time of the inferior
pressure level is usually less than that of the
superior pressure level, functioning only as a
temporary relief. Cycle (transition between
inspiration and expiration) occurs by flow as it
falls to a certain percentage of its maximum
reached value.
Without spontaneous breathing, APRV is
similar to the controlled pressure mode,
differing from this by adjusting the times
(superior and inferior) rather than the
respiratory rate.
The onset of inspiration occurs when the
patient makes an effort that is recognized by
the ventilator according to the adjusted trigger.
If the backup is active and the patient goes into
apnea, the onset of inspiration will occur
according to the set apnea time.
Adjusted Parameters:
•
SUPERIOR PR.
•
SUPERIOR T.
•
INFERIOR PR.
•
INFERIOR T.
•
O
2
CONCENTRATION
•
ΔPS (Support Pressure)
•
LIMIT PRESSURE
•
CYCLE (% FLOW)
•
PRESSURE TRIGGER
•
FLOW TRIGGER
•
RISE TIME
•
FLOW (
- NEONATAL);
•
BACKUP
•
o
VCV Backup
▪
VOLUME
▪
RATE
▪
FLOW
▪
PEEP
▪
FLOW WAVE
▪
PAUSE
o
PCV Backup
▪
CONTROL
PRESSURE
▪
RATE
▪
INSPIRATORY
TIME
▪
PEEP
o
PLV-NEONATAL
Backup
▪
INSP PRESSURE
▪
RATE
▪
INSPIRATORY
TIME
o
Automatic Backup
(1)
1
– Whenever the set
apnea time is reached, the
ventilator triggers a
ventilator cycle, the setting
of which is based on the
current mode settings.