Ch. 5 Pilbeams Flashcards
Ventilator provides all the energy nesseccary to maintain effective _________.
Alveolar ventilation
Vt is ______ for pt?
Adequate
Pt participates in ______?
WOB
Mandatory breath?
Breaths which the ventilator control the timing, Vt, or inspiratory pressure.
Spontaneous breath?
Pt controls the timing and Vt
Assisted breath?
In an assisted breath, all or part of the breath is generated by the ventilator, which does part of the WOB for the patient.
What happens when volume is the control variable?
the volume selected is constant and independent of what happens to pressure when the patient’s lung characteristics
What is the primary advantage of volume control?
It guarantees a specific volume delivery and volume of expired gas (Ve) regardless of changes in lung compliance and resistance or patient effort.
What is the goal of volume controlled?
to maintain a certain level of PaCO2
Pressure as control variable?
To set pressure as the independent variable; that is, the pressure remains constant, but volume delivery (the dependent variable) changes as lung characteristics change.
What are some advantages of pressure control?
• reduces the risk for overdistention of the lungs by limiting the amount of positive pressure applied to the lung.
• Second, the ventilator delivers a decelerating flow pattern during pressure-controlled ventilation
Pressure controlled is considered what?
a component of protective strategies for the lung.
Pressure may be comfortable for pt who can do what?
Spontaneously breathe
What are some disadvantages of pressure controlled?
• Volume delivery varies as the patient’s lung characteristics (i.e., lung compliance and airway resistance) change.
• VT and VE decrease when lung characteristics deteriorate
What are the 3 types of timing breaths?
- Continuous mandatory ventilation (CMV)
- Intermittent mandatory ventilation (IMV)
- Continuous spontaneous ventilation (CSV)
With CMV breaths can be _______?
Time triggered or pt triggered
For CMV when breaths are time triggered they are described as?
controlled ventilation or the control mode
When breaths are pt triggered they are described as?
assisted ventilation
Controlled (time-triggered) ventilation is appropriate only when a patient cannot …..?
Make an effort to breathe
Controlled ventilation is appropriate for pts who are….?
Patients who are obtunded because of drugs, cerebral malfunction, spinal cord or phrenic nerve injury, or motor nerve paralysis may be unable to make voluntary efforts
Assisted ventilation?
time-triggered or patient-triggered CMV mode in which the operator sets a minimum breathing rate, sensitivity level, and type of breath (volume or pressure).
With CMV every breath is?
Time or pt triggered
With PC-CMV all breaths are?
time or patient triggered, pressure targeted, and time cycled.
What is the maximum pressure limit for PC-CMV?
+10cmH2O above the target or set pressure
IMV?
IMV involves periodic volume-targeted or pressure-targeted breaths that occur at set intervals (time triggering).
What happens during IMV?
During IMV, the patient can breathe spontaneously between mandatory (i.e., machine) breaths at any desired baseline pressure without receiving a mandatory breath.
Advantages & disadvantages or CMV and IMV?
What are the 3 spontaneous modes?
• Spontaneous breathing
• Continuous positive airway pressure (CPAP)
• Pressure support ventilation (PSV)
What happens during spontaneous mode?
The pt can breathe spontaneously through a ventilator circuit without receiving any mandatory breaths.
What is PSV?
The ventilator provides a constant pressure during inspiration once it senses that the patient has made an inspiratory effort
PSV is always ….?
Assist mode (pt triggered)
A pressure support breath is…?
patient triggered, pressure limited, and flow cycled.
BiPAP can be …?
• Pt triggered
• Time triggered
• Flow cycled
• Time cycled
What is pressure augmentation?
a dual-control mode that provides
pressure-limited ventilation with volume delivery targeted for every breath.
What is another name for pressure augmentation?
volume-assured pressure support (VAPS)
What happens during (PAug)?
The ventilator begins with a patient-triggered,
pressure-targeted breath (e.g., a pressure support breath), but targets the volume preset by the operator and delivers that volume with
every breath.
What is a key criterion for (PAug)?
The ability to initiate breaths
When was PRVC introduced?
On the servo 300 in the 1990s
What are some other names for PRVC?
Drager - auto flow
Covidien - VC+
Hamilton - adaptive pressure ventilation
What kind of breaths does PRVC give?
patient-triggered
time-triggered
volume-targeted
time-cycled breaths.
What type of breaths does VSV do?
• Pt triggered
• Volume targeted
• Flow cycled
What is set for MMV?
Minute ventilation 70-90% of pts current Ve.
MVV has what?
High rate and low Vt
What is ASV?
A closed loop ventilation and oxygenation mode of ventilation (based on the pts ideal body weight and estimated dead space volume).
What does the clinician set for ASV?
Targeted Ve based on the patients IBW and estimated Vd.
What is APRV?
Controls the high and low pressure in between pts spontaneous breath.
What are the terms for APRV and why do they mean?
The terms Phigh and Plow indicate the levels of pressure administered during APRV, and Thigh and Tlow are used to describe the time spent in high and low airway pressures.
What is PAV?
pressure, flow, and volume delivery are proportional to the patient’s spontaneous effort.
Ex. As the patient’s inspiratory effort increases, the flow from the ventilator increases proportionally.
In PAV the amount of pressure the vent produces is based on 2 factors?
(1) the amount of inspiratory flow and volume demanded by the patient’s effort
(2) the degree of amplification selected by the clinician (which determines the extent of ventilator response to patient effort).
PAV is a ______ feedback system?
Positive
