Treaton MV200, User Manual

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Appendix 1.3 Description of SIMV/VC, SIMV/PC, SIMV/DC modes
App.1-3
Appendix 1.3 Description of SIMV/VC, SIMV/PC, SIMV/DC modes
SIMV/VC, SIMV/PC, SIMV/DC modes - Synchronized Intermittent Mandatory Ventilation with
volume control, pressure control and double control.
In these modes pressure support of spontaneous patient’s breath (by PS - Pressure Support) is
also realized. If device detects independent respiratory attempts of the patient, these breaths
are carried out synchronously with them, in case of absence of attempts - automatically upon
the end of the set interval of expectation. In intervals between ventilator’s breaths the patient
can independently breathe through the circuit.
Independent breaths of the patient are supported by the set level of pressure, invariable
throughout all time (support pressure, PS). Criterion of the spontaneous breath termination is
flow falling to the set level ETS from the maximum. Reserve criterion is time, if the flow does not
manage to decrease to ETS for the maximum allowed inspiratory time.
Decreasing of the mandatory breaths frequency and tidal volume (inspiration pressure) pro-
motes increasing of part of independent breath, and on the contrary.
The SIMV/DC mode is analogue of the SIMV/PC mode, except that the ventilator’s breath is
carried out according double control (DC) method similarly to the PCV-VG mode.
Figure App. 1.3 – SIMV mode
Paw
Pi
t
PEEP
Flow
t
TrigWnd = 20 %
Fmax
ETS,
% from Fmax
Trigger window has not al-
ready started, so there is a
spontaneous inspiration: no
inspiratory pause, end of in-
spiration by ETS
PS is usually less
than Pi