Covidien Puritan Bennett 540, User Manual, Page: 125 / 141

Puritan Bennett 540™ Ventilator User’s Manual
D-1
D Modes and Breath Types
D.1 Modes of Ventilation
This chapter is a general description of the various modes of ventilation and breath types available
with the Puritan Bennett 540™ Ventilator.
D.1.1 Assist/Control (A/C) Modes
When set to an Assist/Control mode, machine-initiated breaths are delivered at a clinician-set volume
or pressure, inspiratory time, and rate. If the patient triggers a spontaneous breath between machine
breaths, the ventilator will deliver a breath based on the volume or pressure settings and inspiratory
time.
Whether initiated by the patient or the ventilator, all breaths are delivered at the same preset volume
or pressure and inspiratory time.
The names of the Assist/Control modes are:
•
VOL A/C, if the breaths are based on a volume setting
•
PRES A/C, if the breaths are based on a pressure setting
D.1.2 SIMV Modes
When set to a SIMV (Synchronized Intermittent Mandatory Ventilation) Mode, machine-initiated
breaths are delivered at a clinician-set volume or pressure, inspiratory time, and rate. These
mandatory breaths are synchronized with patient effort. If the patient triggers a spontaneous breath
between machine breaths, the ventilator will deliver a spontaneous breath, which is pressure-
supported.
CPAP spontaneous breaths are not available in SIMV modes.
The names of the SIMV modes are:
•
V SIMV, if mandatory breaths are based on a volume setting
•
P SIMV, if mandatory breaths are based on a pressure setting
D.1.3 CPAP Mode
In CPAP, the ventilator maintains a constant level of pressure in the patient’s airway. If your clinician
has prescribed CPAP, you should talk to him or her for a further explanation of how CPAP operates.
Note:
The default ventilation mode setting is PRES A/C; for more information, see below.