Ch. 5 Selecting the vent and the mode Test 2 Flashcards
During Full ventilatory support, the ventilator
provides all the energy necessary to maintain effective alveolar ventilation
Full vent support results in PaCO2 values ____ or PaCO2 that is ________ for the pt (eucapnic breathing)
<45;
normal
Full vent support is provided when the vent rates are
high (8breaths/min or more) and Vt is adequate for the pt
Any degree of MV in which set machine rates are lower than 6 breaths/min and the patient participates in the WOB to help maintain effective alveolar ventilation
Partial ventilatory support
With partial support, the pt must actively
participate in ventilation to maintain adequate levels of PaCO2
What are some partial support modes
- SIMV
- PSV
- VSV
- PAV
- MMV
Partial support mode should be avoided in pts with
ventilatory muscle fatigue and when a pt has a high WOB level
Example of full and partial vent support:
A patient who is unconscious, comatose, or has experienced a cardiac arrest will receive full support. A patient who is partially awake, waking up from surgery, or weaning, will be placed on partial support mode
Something to know
The breath type and pattern of breath delivery during MV constitute the
mode of ventilation
The mode is determined by the following factors:
- Type of breath (mandatory, spontaneous, assisted)
- Targeted control variable (volume or pressure)
- Timing of breath delivery (CMV, IMV, CSV)
_______________ breaths are breath for which the vent controls the timing, the Vt, or inspiratory pressure
Mandatory
Example for mandatory breath:
A pt-triggered, volume-targeted, volume-cycled is a mandatory breath. The vent controls the Vt delivery
Something to know
For this type of breath, the pt controls the timing, and the Vt
Spontaneous breaths
For spontaneous breaths the volume or pressure (or both) delivered is not set by the RT, but rather is….
based on pt demand and pt lung characteristic
Assisted breaths have characteristics of both
mandatory and spontaneous breaths
_____ or _______ of the breath is generated by the vent, which does part of the WOB for the pt in assisted
All or part
If the airway pressure rises above baseline during inspiration the….
the breath is assisted
Example of Assisted breaths:
1. VCAC, the pt can start the breath and the machine can end it
- During the pressure support mode the RT sets the target pressure but the pt initiates the breath (pt triggered)
Something to know
During the pressure support mode, the vent delivers the set pressure above the….
baseline pressure to assist the pt’s breathing; the pt cycles the breath
Control variables are
independent variables
What is the primary advantage of volume-control ventilation?
It guarantees a specific volume delivery and volume of expired gas (VE), regardless of changes in lung compliance and resistance or pt effort
What is the goal of volume-controlled ventilation?
To maintain a certain level of PaCO2
What is a disadvantage of volume-controlled ventilation
ventilation becomes evident when lung condition worsens, which can cause the peak and alveolar pressure to rise, leading to Barotrauma (alveolar distention)
When lung conditions improve,
less pressure is required to deliver the volume and ventilating pressure decline