Lecture 4: Breathing systems, scavenging, and intubation supplies Flashcards
Where are some common areas to find a leak in an anesthesia machine?
- neck of reservoir bag
- breathing circuit hoses
- any hose connection
- inlet/outlet to vaporizer
- one-way valves
- CO2 absorbing canister
- Flow meter
What is the purpose of the breathing system?
Deliver O2 +/- anesthetic gases and eliminate CO2
What are the two main types of breathing systems?
- Non-rebreathing
- Rebreathing
List the components of the rebreathing system
- fresh gas source
- unidirectional valves
- breathing hoses
- breathing system pressure gauge
- CO2 absorber
- APL valve
- reservoir bag
What are the advantages to a rebreathing system?
Can use lower O2 flow rates and is easy to set up and use
What are the disadvantages to a rebreathing system?
Increased resistance for smaller patient and more components to work with
What is the recommended oxygen flow rates for a low-flow circle system?
10-22 mL/kg/min
What is the recommended oxygen flow rates for a semi-closed circle system?
22-44 mL/kg/min
What is the purpose of the breathing system pressure gauge?
Measures the existing pressure within a breathing system (mmHg or cmH2O)
List the components for the non-rebreathing system
fresh gas source, expiratory limb or coaxial breathing hose, open/close valve, reservoir bag
What are the typical oxygen flow rates for the non-rebreathing system?
200-300 mL/kg/min
What are the advantages to the non-rebreathing system?
Less resistance to breathing for patient, little to no dead space and fewer components that can leak or malfunction
What are the disadvantages to the non-rebreathing system?
Higher O2 flow rates required to get rid of CO2 leads to pollution to environment and can contribute to hypothermia
What are the two types of passive scavenging systems?
- Charcoal absorption
- To outside wall or window
What is the active form of scavenging systems?
Central vacuum collection
What are the advantages of charcoal absorption?
Mobile, initial cost is low, easy to set up
what are the disadvantages of charcoal absorption?
Must be replaced after gaining 50g of weight, use limited to lower oxygen flow rates, adds resistance, environmental impact
How do you measure the proper length of the ETT?
Length should not extend distally beyond the thoracic inlet or rostrally beyond incisors
List the 4 types of ET tubes
- Murphy (most common)
- Magill
- Cole
- Guarded or armored
What is dead space?
Term that describes portions of the breathing passages that contain air but there is no gas exchange
Describe the “murphys eye” design ETT
An oval hole positioned on the bevel facing the opening of the tube
Describe the Magill ETT
same design as the murphy but with no “eye”
Describe the Cole ETT
Uncuffed, has a shoulder near the distal end
Describe guarded or armored tubes
Made of silicone rubber, have steel wire or nylon coil embedded in the wall, resists kinking, more expensive
