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Term
Respiratory rate (Freq.)
Respiratory time ratio (I:E)
Tidal volume (Vt)
Trigger
Trigger threshold
Trigger time slot
Volume-controlled ventilation
Number of applied ventilation cycles per minute (total of
mandatory and spontaneous breaths)
The ratio of inhalation time T
Set volume to be applied per mechanical breath.
A trigger (triggered by the patient) is a switch element enabling the
patient and the ventilator to interact. A pressure/flow signal
triggers inspiration (device: flow trigger).
Threshold which must be reached for the ventilator to recognize
the patient's effort to inhale. The trigger threshold can be set in the
unit:
– Inspiratory: 1 l/min - 15 l/min and out.
– Expiratory: 5% - 50% of maximum flow
Time slot in which the patient can trigger a mechanical breath by
his/her efforts to inhale (triggers). The length of the trigger time
slot depends on the ventilation mode and its settings. Examples:
With SIMV + ASB this is 20% of the expiration time before the
mandatory mechanical breath; with S-IPPV it is % of the expiration
time.
Volume-controlled ventilation determines the volume which is
administered to the patient (tidal volume Vt as the control variable).
Airway pressure results from the compliance of the lungs and the
inhaled volume. Example: IPPV ventilation mode.
Explanation
to exhalation time T
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Glossary
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EN
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