Breathing Systems Flashcards
Which gases can pass through the fresh gas inlet?
All of the gases.
The regulator or reduction valve reduces the psi to what value?
50 psi
Delivering oxygen and also possibly anesthetic gases as well as eliminating carbon dioxide is done by what system?
Patient Breathing System (PBS)
What are the 2 main types of patient breathing systems?
- Rebreathing
- Non-rebreathing
What should be done to a patient breathing system (PBS) prior to use?
Leak check
Which patient breathing system has a one-way circular pattern?
Rebreathing (circle) system
With which patient breathing system does the patient inhale the same anesthetic as they are exhaling?
Rebreathing (circle) system
What is the unit of measurement used in the flowmeter?
L/min
Which type of breathing system needs a form of CO2 absorption?
Rebreathing (circle) system
Why are rebreathing (circle) systems not good for smaller patients?
There are more components so there is an increased resistance for smaller patients.
A build up of CO2 can lead to what?
Acidemia
Rebreathing (circle) systems should be used for animals above what weight?
3 kg
A pediatric rebreathing hose should be used for patients under what weight?
15 lbs
What type of rebreathing hose is used for patients 15-300 lbs?
Standard adult circle hose
What are 2 types of hoses used with a rebreathing (circle) system?
- Y
- Universal F
Do circle system valves increase or decrease resistance to breathing?
Increase resistance to breathing
Circle system valve incompetence can lead to what?
Rebreathing
What can increased rebreathing lead to?
CO2 values going up causing an acidosis.
What does APL stand for?
adjustable pressure limiting
What is another name for a “pop-off” valve?
Adjustable Pressure Limiting Valve
What limits pressure build-up within the circuit?
APL/pop-off valve
Does an APL/pop-off valve need to be open or closed when administering a breath?
Closed
APL/pop-off valves should always be open except in what circumstances?
Delivering manual, controlled or assisted ventilation
What would happen if the APL/pop-off valve were closed when administering a breath?
Build up of pressure within the circuit could lead to barotrauma.
What measure pressure within the breathing circuit?
Breathing System Pressure Gauge
What is the breathing system pressure gauge typically located next to?
Flow meter
A breathing system pressure gauge should always read what unless what two events are occurring?
- Zero
- Performing leak checks or providing IPPV
The breathing system pressure gauge is measured in what units?
cm H2O
The oxygen cylinder pressure gauge is measured in what units?
PSI
The non-rebreathing system pressure gauge is measured in what units?
cm H2O
What type of breathing system is a carbon dioxide absorber used for?
Rebreathing (circle) system
How full should a carbon dioxide absorber be filled?
One inch from the top.
What is commonly used as a carbon dioxide absorber?
Soda Lime
The ingredients of soda lime react with what two types of molecules?
- CO2
- Water
What type of a reaction takes place in a carbon dioxide absorber?
How does this make the canister feel?
- Exothermic reaction
- Warm to the touch
Soda lime removes what from a circle breathing system?
CO2
What are 2 precautions to take when handling soda lime?
- Use gloves
- Do not inhale
Soda lime can generally be used for how long with small animals?
With large animals?
- 8 to 12 hours
- 6 to 8 hours
What is something that should be done with the soda lime on a regular basis?
Why?
- Shake the canister
- Get rid of the channels that form from use.
Why is it important to monitor the amount of time soda lime is used?
It ceases to absorb CO2 after a while.
What is the color change seen with soda lime?
What is this due to?
- Changes to purple/pink
- Due to a chemical reaction
What can happen with a rebreathing system if the oxygen is left on after a procedure?
Carbon monoxide can be given off and kill the patient.
What are 4 signs that the carbon dioxide absorber has been exhausted?
- Increased EtCO2 and InCO2
- Increase ventilation
- Increase in HR and BP initially (then drops)
- Red mucous membranes
How do you calculate what size reservoir/rebreathing bag to use?
Body weight x Tidal volume x 5
What is the normal tidal volume range?
- 10-20 mL/kg
What are 3 uses for a reservoir/rebreathing bag?
- Respiratory monitor
- IPPV
- Inspiratory reserve
When manually squeezing a reservoir/rebreathing bag, what is the rate on the breathing system pressure gauge that is trying to be reached?
- 20 cm H2O
What is the high flow rate for a rebreathing system?
When is this used?
- 50-100 mL/kg/min
- Start and end of inhalation anesthesia
What is a benefit of using a high flow rate at the start of inhalation anesthesia with a rebreathing system?
Decreased time required to achieve ideal anesthetic concentration.
What are the 2 flow rates that can be used for maintenance during inhalation anesthesia with a rebreathing system?
- Semi-closed: 20-50 mL/kg/min
- Low flow: 10-20 mL/kg/min
What type of breathing system is used for patients weighing 3 kg or less?
Non-rebreathing system
Do non-rebreathing systems have carbon dioxide absorbers?
No
What washes out the CO2 in a non-rebreathing system?
What does this require?
- Fresh gas
- Higher O2 flow rate
Which breathing system has less resistance and fewer components?
Non-rebreathing system
Which breathing system has more gas waste and atmosphere pollution due to high flow rates?
Non-rebreathing system
What can a high flow rate contribute to?
Hypothermia
Do you find little to no dead space with a low or high flow rate?
High flow rate
What are 2 examples of non-rebreathing hoses used at Ross?
- Mapleson D
- Mapleson F
What is the flow rate used with a non-rebreathing system?
200-300 mL/kg/min
What is the minimum flow rate needed for a non-rebreathing system?
What can be seen if this minimum is not met?
- 1 L/min
- Elevations of inspiratory CO2
T/F: Flow meters are set up to deliver more gas than a patient can take up.
True
T/F: In the absence of scavenging, gases will remain circulating in the system.
False - In the absence of scavenging, gases will flow into the room.
Pollution from poor scavenging can cause what?
Spontaneous abortion and fetal injury
According to NIOSH standards, what is the recommended level that occupational exposure to halogenated anesthetic agents should be kept below?
2 ppm
How many ppm is 100% gas?
1% gas?
- 1,000,000 ppm
- 10,000 ppm
At what ppm can we smell anesthetic gases?
About 125 ppm
As long as a leak is under what value, the machine can still be used?
Less than 300 mL
A minimum of how many air changes should be made per hour?
15 air changes per hour
What are 3 examples of passive scavenging systems?
- Floor drop
- Charcoal absorption
- Outside wall or window
What is an example of an active scavenging system?
Vacuum collection
What is an advantage to charcoal absorption?
Absorbs halogenated anesthetic gases
What are 4 disadvantages to charcoal absorption?
- Does not absorb N2O or CO2
- Must be replaced often, so increased cost over time
- Flow limited
- Added resistance
What should be done before a new charcoal absorber is used?
It should be weighed and the weight recorded in grams.
When should a charcoal absorber be discarded?
How long does this usually take?
- When it has gained 50 grams from its original weight.
- Usually 8-12 hours
What are 4 other possible sources of gas pollution?
- Gas sampling monitors (capnograph)
- Filling vaporizers
- Recovery rooms
- Induction chambers/face masks
What should be worn when filling a vaporizer?
Charcoal mask
Don’t forget to do what once done filling a vaporizer?
Put cap back on liquid anesthetic container.
Which is safer, a funnel/pour fill or a key fill?
Key fill
What needs to be done to the vaporizer before beginning filling?
Turn vaporizer dial off
The O2 flow that is passing through the vaporization chamber will exert sufficient pressure on anesthetic liquid causing it to flow out of the port if what is done?
Vaporizer left on during filling
How many air changes should there be in a recovery room?
15-20 air changes/hour
T/F: A patient can be kept on oxygen and the breathing circuit utilized to scavenge the patient’s lungs at the beginning of recovery.
True
It is recommended that detection badges are used to test a minimum of two sights how often?
Twice per year
What is used for the purpose of administration of inhalation anesthesia with reduced waste gas pollution?
Endotracheal tubes
Do endotracheal tubes reduce or increase the risk of saliva or regurgitated contents of the stomach being inhaled?
Reduce the risk
What can be administered through an endotracheal tube?
Oxygen
What can an endotracheal tube allow for?
IPPV
What is the most common material used for endotracheal tubes?
PVC
Which tubes have thicker walls, oral or nasal?
Oral
Which type of tube is used more frequently in animals, cuffed or uncuffed?
Which species is the exception to this?
- Cuffed
- Birds
What can cause pressure ischemia or respiratory obstruction when collapse occurs?
Over pressured cuffs
Tracheal ischemia can occur at what level?
27 cm H2O
Which type of tube as an oval hole positioned on the bevel facing the opening of the tube?
Murphy tubes
What does a “Murphy’s eye” help to prevent?
Obstruction
Armored, wire-reinforced or spiral embedded tubes resist what?
What type of procedures are these good for?
- Kinking
- Head or neck procedures
What type of tube is uncuffed and characterized by a “shoulder” near the distal end?
Cole tubes
Why should the largest diameter possible be used for an endotracheal tube?
Decreased airway resistance
An endotracheal tube should extend to what anatomical location in the patient?
Thoracic inlet
What are 2 things that can happen in an endotracheal tube is too long for the patient?
- Increased resistance
- One lung ventilation
What is the term that describes portions of the breathing passages that contain air but here is no gas exchange?
Dead space
What are 5 examples of dead space?
- Mouth
- Nasal passages
- Pharynx
- Trachea
- End of ET tube/Y piece of PBS
What allows for visualization, provides a light source and allows increased accessibility to the airway?
Laryngoscope
Where should pressure be applied with a laryngoscope?
Light pressure to the base of the tongue, just underneath the epiglottis.
There should be no gas escaping around the ET tube at what level to make sure the cuff is not under-inflated?
The gas should be able to escape again at what level to make sure the cuff is not overinflated?
- 20 cm H2O
- 30 cm H2O
What can be used to check a cuff for over/under inflation?
Posey cufflator
What are 2 different ways to tie in an ET tube?
- Around the ears
- Around the maxilla
What are 5 possible complications that can be seen with using an ET tube?
- Damage to larynx
- Damage to trachea
- ET tube lumen obstruction
- Endobronchial intubation (one lung ventilation)
- ET tube damage
