Measured And Calculated Parameter Definitions - ResMed Astral Series Clinical Manual

Appendix A: Definitions

Measured and calculated parameter definitions

The following measured and calculated parameters are displayed during configuration or during
ventilation. Each Ventilation mode details the parameters displayed.
Parameter
FiO
2
I:E
Leak
MV
MVe
MVi
Pressure
PEEP
Pmean
% Spont cycle
% Spont trig
PIF
PIP
Pulse rate
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Definition
Average of percentage of Oxygen delivered to circuit.
I:E is the ratio of the inspiratory period to the expiratory period.
The measured I:E ratio is displayed as a monitored parameter during ventilation.
The expected I:E ratio is calculated and displayed on the settings screens if the Resp.
rate setting is not set to Off.
Leak is the average unintentional leak. It is reported as a percentage for Double limb
circuits and as a flow for Single limb circuits with intentional leak.
The measured Leak is displayed as a monitored parameter during ventilation.
Minute Ventilation (MV) is the product of the Target Patient Rate (Target Pt Rate) and
expired tidal volume averaged over the last eight breaths.
The MV is displayed as a calculated parameter during iVAPS configuration.
Expiratory Minute Volume (MVe) is the product of the respiratory rate and expired tidal
volume averaged over the last eight breaths.
The measured MVe is displayed as a monitored parameter during ventilation.
Inspiratory Minute Volume (MVi) is the product of the respiratory rate and inspired tidal
volume averaged over the last eight breaths.
The measured MVi is displayed as a monitored parameter during ventilation.
Pressure is the current airway pressure of the patient as measured at the patient port.
The measured Pressure is displayed as a monitored parameter during ventilation.
End expiratory pressure (PEEP) is the airway pressure measured 50 ms prior to the end of
the last expiration.
The measured PEEP is displayed as a monitored parameter during ventilation.
Mean airway pressure of the patient over the last breath.
% Spont cycle is the percentage of breaths that are spontaneously cycled over the past
20 breaths.
% Spont trig is the percentage of breaths that are spontaneously triggered over the last
20 breaths.
The measured %Spont Trig is displayed as a monitored parameter during ventilation.
Peak Inspiratory Flow (PIF) is the maximum flow reached during the last inspiration.
The measured PIF is displayed as a monitored parameter during ventilation.
The expected PIF is calculated and displayed for volume controlled breaths on the
settings screens when the Inspiratory Phase Duration Option is set to Ti.
Peak Inspiratory Pressure (PIP) is the maximum airway pressure reached during the last
inspiration.
The measured PIP is displayed as a monitored parameter during ventilation.
The measured Pulse rate (pulse) is displayed as a monitored parameter when a pulse
oximeter is used.