07: Basic Vent Function Flashcards
Positive pressure ventilation
Airway pressure applied to patients airway through artificial airway
Negative pressure ventilation and types
Machine creating negative extrathoracic pressure
Iron lung
Chest cuirass
Two ways vents can be triggered into inspiration
Patient or machine
Trigger
Starts inspiration
pressure trigger
Patient spontaneously inhales -> drops pressure -> triggers inspiration
Time triggered
Machine begins inspiration at preset time
(RR:10 -> triggers every 6 seconds)
Flow triggered
Patient spontaneously inhales -> changes flow -> triggers
Advantages of flow trigger
Improved response to pt effort and requires less effort from pt
Base flow range on flow triggered ventilation
8-10lpm
Trigger flow range on flow trigger ventilation
1-3lpm
Flow trigger works in
All modes
Spontaneous modes of ventilation
Pt determines RR, inspiratory flow rate, and size of breath
PSV SIMV CSV
Exhalation valve
Closes on inspiration -> passive exhalation
MUST BE FUNCTIONAL FOR PEEP
Internal circuit
Air inside machine -> external circuit
External circuit
gas from vent -> pt -> exhalation valve
Time cycled
Inspiration ends when set time expires
PIP reached on time cycled?
Machine holds inspiration until inspiratory time expires
Flow cycled
Inspiration ends when minimum flow met
Pressure cycled
Inspiration ends when preset pressure is met
Changes in airway resistance/lung compliance in pressure cycled cause what to change
Volume and flow
Volume cycled
Inspiration ends when preset volume delivered
Changes in resistance and compliance in volume cycled change what?
Pressure
CMV
Continuous mandatory ventilation
NO spontaneous breaths
IMV
Intermittent mandatory ventilation
Mandatory rate set, pt can spontaneously breath additional breaths
SIMV
Synchronized intermittent mandatory ventilation
If machine senses pt effort, it synchronizes the mandatory and spontaneous breaths
CSV
Continuous spontaneous ventilation
All breaths spontaneous
Mode
Control selecting how machine will deliver inspiration and expiration
PIP
Peak/maximum inspiratory pressure
Pressure required to deliver set volume
MAP
Mean airway pressure
Average pressure of full breath cycle
MAP increased?
Blood flow to heart decreased
A/C
Assist/control
Assisted breaths if breathing over set rate
Pressure support is only in
Spontaneous breaths
SIMV spontaneous breaths are delivered at what volume?
Volume pt desires
Spontaneous inhalation in A/C
Sensitivity adjusted to allow the breath to achieve set Vt in VC or PIP in PC