Work of breathing is _____ and ____.
resistance
compliance
Circle System Components
- Carbon Dioxide Absorbent
- Carbon Dioxide Absorbers
- Unidirectional Valves
- Inspiratory/Expiratory Ports
- Breathing Tubes
- Y-Piece
- Fresh Gas Inlet
- APL Valve
- Reservoir Bag
- Bag/Ventilator Switch
- Ventilator
- Pressure Gauge
- Respiratory Gas Monitor Sensor
- Airway Pressure Monitor Sensor
- Respirometer
Carbon Dioxide Absorbant types (2)
- soda lime
- barium hydroxide lime
How is carbon dioxide absorbed?
carbonic acid neutralization
When you should change absorbent? (3)
CO2 in inspired gases
Color change
Heat in canisters
Tube length does affect dead space because of unidirectional gas flow. True or false?
false
does not
Breathing Tubes—colored end is inspiratory. True or false?
true
What is the connector between breathing tubes & endotracheal tube or supraglottic airway device?
Y-piece
_________ is where fresh gases with/without anesthetics enter the breathing circuit
fresh gas inlet
APL Valve functions: (2)
- Controls pressure in breathing system
- Releases gases to scavenging system
Reservoir bag function (4)
- Allows gas to accumulate during exhalation (reservoir of gas for next inspiration)
- Method of generating positive-pressure ventilation
- Way to monitor spontaneous respiration
- Protects patient from excessive pressure in breathing system
What will warn clinicians of high or low-pressure conditions in breathing system?
Airway Pressure Monitor Sensor
What are the objectives of a circle system design?
- Maximum inclusion of fresh gas in inspired mixture & maximum venting of alveolar gas
- Minimize absorbent dessication
- Minimal absorbent consumption
- Accurate respirometer readings
- Maximal inspired gas humidification
- Minimal dead space
- Low resistance
- Minimal pull on mask, ETT, or LMA
- Convenience
In CO2 absorbant, smaller granules have high absorptive surface area & high resistance to gas flow. True or false?
true
Drier absorbent will absorb & degrade volatile anesthetics more. True or false?
true
Do not change absorbent during the case. True or false?
true
The inspiratory and expiratory port diameters are:
22–mm and male
What gases are found inside the bellows? (3)
- FGF
- agent
- patient exhaled gases
Most common fresh gas inlet location
Upstream of the inspiratory valve and downstream from the absorber
Most common location for the APL valve:
- Near the reservoir bag downstream of the expiratory valve & upstream of the absorber
- In this position, fresh gas will be vented only if the fresh gas flow is high.
Most common reservoir bag location:
- Between the expiratory unidirectional valve & the absorber
- With manually assisted/controlled ventilation, more efficient absorbent use occurs with the bag upstream of the absorber.
- A disadvantage of placing the bag upstream of the absorber is that a sudden increase in pressure from squeezing the bag may force dust from the absorber into the inspiratory tubing.
Most common ventilator location:
- Upstream of the absorber, near the APL valve
During spontaneous inspiration, gas flows from the reservoir bag thru the absorber where it joins with the fresh gas & flows to the patient. True or false?
true
During exhalation, exhaled gases pass into the reservoir bag until it is full then excess gases are vented thru the APL valve. True or false?
True
