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P-SIMV (Pressure Controlled Synchronized Intermittent Mandatory Ventilation)
This mode is a combination of mandatory and spontaneous breaths. Mandatory breath is
pressure controlled and spontaneous breath is pressure supported.
Excessive increase of pressure or deliverd volume could cause terminating the inhalation. In
this situation, applied Ti may shorter than set Ti (see the alarms chapter).
Note:
When changing the Rate and Ti parameters, the values of Te and I: E are displayed on the
parameter setting menue.
Note:
During inhalation, if the airway pressure for any reason (such as the patient's cough) exceeds
the value specified for it, the exhalation valve opens and prevents further increase in pressure.
The pressure curve in P-SIMV mode is shown in the below figure. The patient triggers a
mandatory breath in synchronization with respiratory effort within Expectation window and
triggers a pressure supported breath within Spontaneous window.
Figure 8-5- Pressure curve in P-SIMV mode
P-SIMV
mode is similar to V-SIMV mode except that mandatory breaths in V-SIMV mode
are volume controlled, but in P-SIMV mode are pressure controlled.
Adjustable parameters in this mode are:
Definition
Parameter
Percentage of delivered oxygen to the patient
2
O
Mandatory breaths per minute
Rate
Inspiratory time
i
T
Positive end expiratory pressure
PEEP
Inspiratory pressure above PEEP in mandatory breaths
control
P
Pressure more than PEEP that applies to spontaneous breaths.
support
P
The method of detecting the patient's respiratory effort (flow or pressure).
Trigger
