Hoffrichter CARAT II pro, User Manual

Page: 84 / 202

84 Chapter 5: Ventilation modes
P-SIMV MODE
P ressure Controlled S ynchronized I ntermittent Mandatory Ventilation
Main features
• Pressure controlled
• Device or patient triggered
• Time controlled
• Fixed frequency
• Spontaneous breathing possible
The SIMV mode provides a combination of pressure controlled ventilation and
pressure assisted spontaneous breathing.
Pressure controlled ventilation is based on a defined respiratory rate and a defined
inspiration time.
The inspiratory pressure (IPAP) as well as the end-expiratory pressure (PEEP) define
the range of pressure for ventilating the patient. The pressure increase time from
PEEP to IPAP can be set via the "Ramp" parameter in 5 levels.
The inspiration volume is automatically adjusted to the condition of the lung (com-
pliance and resistance). The mechanical ventilation cannot influence by the patient
spontaneous breathe.
Spontaneous breathing on the patient’s part is possible between the ventilator
strokes if the trigger thresholds for inspiration and expiration triggers are reached.
During inspiration, spontaneous breathing is supported by a pressure (PS) that can
be selected beforehand and is independent of the IPAP. The length of the spon-
taneous breaths and the inspiration time are exclusively defined by the patient.
The mechanical breaths are adjusted to spontaneous breathing in terms of time.
If, for example, a spontaneous inspiration occurs shortly before a SIMV period is
started (within a specific expected time window = 5 seconds), the mechanical ven -
tilation is synchronized to the breathing of the patient. Since the synchronization of
the mandatory ventilation shortens controlled ventilation by
∆
t and the frequency
would be increasing, the following breath will be extened by
∆
t.