Triggering And Cycling; Leak Management - Vsync; Rise Time Adjustment; Ticontrol™ - Inspiratory Time Control - ResMed VPAP ST Clinical Manual

Triggering and cycling

(S and ST modes) Under normal conditions, the VPAP device triggers (initiates IPAP) and cycles
(terminates IPAP and changes to EPAP) as it senses the change in patient flow. Patient breath detection
is enhanced by the VPAP device's automatic leak management feature—Vsync.
In addition, the VPAP device has adjustable trigger/cycle sensitivity to optimise the sensing level
according to patient conditions.
Adjustable trigger sensitivity
Patient flow
Leak Management – Vsync
Vsync monitors and compensates for leak by continuously and automatically adjusting the baseline flow.
This enables reliable triggering and cycling while maintaining the set pressures.

Rise time adjustment

(S, ST and T modes) Rise time sets the time taken for the VPAP device to reach IPAP . The greater the
rise time value, the longer it takes for pressure to increase from EPAP to IPAP .
Patients with a high ventilatory demand may prefer a shorter rise time, while patients who are slow
breathers may prefer a longer rise time.
Note: A prolonged rise time inhibits fast pressurisation, therefore, rise time should not be set longer than
Ti Max or the patient's normal inspiratory time.
TiControl™ – Inspiratory Time Control
(S and ST modes) Unique to ResMed CPAP and bilevel devices, TiControl allows the clinician to set
minimum and maximum limits on the time the device spends in IPAP . The minimum and maximum time
limits are set at either side of the patient's ideal spontaneous inspiratory time, providing a 'window of
opportunity' for the patient to spontaneously cycle to EPAP .
The minimum time limit is set via the Ti Min parameter and the maximum time limit is set via the Ti Max
parameter.
TiControl's Ti Max and Ti Min parameters play a significant role in maximising synchronisation by
effectively intervening to limit or prolong the inspiratory time when required. This ensures synchronisation
even in the presence of significant mouth and/or mask leak.
Very low
Patient flow
Medium
Very high
Adjustable cycle sensitivity
Very high
Medium
Very low
5
English