Operating Information; Modes Of Operation; Leak Management - Vsync; Epap And Pressure Support - ResMed H5i Clinical Manual

Operating information

This VPAP Adapt device uses internal pressure and flow sensors in the air path to respond reliably to
patient flow rates even in the presence of most normal leaks in the patient circuit.

Modes of operation

The following table describes the operating modes available on the VPAP Adapt.
Mode
CPAP mode
Treats obstructive sleep apnea where a fixed pressure not greater than
20 cm H O is set. Therapy is delivered at this pressure for the duration of the
2
treatment session.
ASV mode
Treats central sleep apnea and/or mixed apneas and periodic breathing by
automatically adjusting the pressure support (PS). In ASV mode, the expiratory
positive airway pressure (EPAP) is adjusted by the clinician to maintain upper
airway patency, while Min PS and Max PS restricts the range of automatically
adjusted pressure support.
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.

EPAP and Pressure Support

(ASV mode) EPAP can be adjusted to maintain upper airway patency.
Pressure Support (PS) is defined as the difference between the peak pressure at the end of inspiration,
and the minimum pressure at the end of expiration (ie, the amplitude of the pressure waveform
delivered).
The pressure support trigger points (Inspiration:Expiration and Expiration:Inspiration) are set automatically
based on measurement of the patient respiratory flow. ASV mode automatically adjusts pressure support
between Max PS and Min PS to keep the patient's respiratory flow even.
ResMed recommends maximum pressure support to be greater than or equal to 10 cm.
Pressure
cm H O
2
Respiratory
airflow
4
Normal effort
Increased ventilation in
response to apnea
25
6
5
0
Normal effort resumes
VPAP Adapt
ü
ü
EPAP + Max PS
EPAP + Min PS
EPAP