Hamilton G5 - Differences between Duopap and APRV; The Many Faces of Duopap and APRV

B-18 624074/07
B Modes of ventilation
Figure B-11. DuoPAP pressure curve
Figure B-12. APRV pressure curve
B.5.3.2 Differences between DuoPAP and APRV
As shown, the two modes differ in the operator settings
required to determine the breath pattern. In DuoPAP, you set
Rate and T high to establish the breath timing. In APRV, you set
T high and T low to establish the time at each level. In DuoPAP
you set P high and PEEP/CPAP to establish the two pressure
levels, while in APRV you set P high and P low.
For clinical use, these two ventilation modes typically differ in
the time allowed at the lower pressure level. When using Duo-
PAP, operators tend to prefer relatively long times at both the
high and low pressure levels to allow spontaneous breathing at
both. When using APRV, operators tend to prefer relatively
long T high and shorter T low settings, this action results with
the spontaneous breathing mostly done at the upper pressure
level. The pressure is then “released” to the lower pressure
level just long enough for the lung volume to decrease, then is
immediately returned to the upper pressure level.
B.5.3.3 The many faces of DuoPAP and APRV
With different patients and with different combinations of
control settings, DuoPAP and APRV can be made to resemble
a variety of conventional ventilation modes. At conventional
settings and in the absence of spontaneous breathing, DuoPAP
and APRV resemble P-CMV. As you decrease the rate, keeping