Gas delivery systems Flashcards
What are the 5 components of a semi open system?
- ETT or face mask
- Reservoir bag
- Reservoir tubing
- Pop off valve
- Fresh gas inlet
What are some examples of semi open systems?
Mapleson A-F, Bain, Circle
What should the fresh gas flow be on a mapleson D during spontaneous ventilation?
2-3 times MV
What should the fresh gas flow be on a mapleson D during controlled ventilation?
1-2 times MV
What kind of system is used on anesthesia vents?
Circle system
What are the seven components of a circle system?
- Fresh gas flow source
- Inspiratory and expiratory unidirectional valves
- Inspiratory and expiratory limbs
- Y piece connector
- APL valve
- Reservoir bag
- CO2 absorber
How do you calculate O2 consumption?
10 x kg ^ (3/4)= ml O2 consumed/min
What are some benefits of rebreathing?
cost reduction, adds humidification
What is a disadvantage of rebreathing?
Do not want rebreathing of CO2
What are some characteristics of open systems? What are two types of open systems?
No gas reservoir bag, no valves, no rebreathing of exhaled gas. 1. Insufflation/Blow by 2. Open drop
What are some advantages/disadvantages of open breathing systems?
Advantages: simple, no rebreathing of CO2, avoids direct patient contact. Disadvantages: no ability to assist of control ventilation, environmental pollution, no control of anesthetic depth of FiO2
What are some advantages of mapleson systems
simple components, lightweight, can provide positive pressure ventilation, low resistance, portable
What are some disadvantages of the Mapleson system?
Requires calculation of FGF, control of anesthetic depth is variable, possible CO2 buildup if FGF not maintained, poor conservation of heat and humidity, FGF is costly
What are some advantages of the circle system?
Relative stability of inspired gases, conservation of moisture and heat, prevention of OR pollution, can be used for closed-system anesthesia, can be used with fairly low flows with no rebreathing of CO2, economy of anesthetics and gases, can scavenge waste gases
What are some disadvantages of the circle system?
Complex design, has at least 10 connections, potential of malfunctioning valves, increased resistance to breathing, less portable than Mapleson
