Anesthesia Machine Basics Flashcards
An anesthetic machine is a highly sophisticated mixing machine that mixes ___ with the ___ vapor in a controlled manner, delivers ___ to the animal, removes exhaled ___ ___, provides a mechanism to assist or control the animals ___, and provides a mechanism for the scavenging of ___ anesthetic gases
- Gas
- Anesthetic
- Oxygen
- Carbon dioxide
- Ventilation
- Waste
What is the purpose of an anesthetic machine? (2)
- Deliver inhalation anesthesia to a patient and removed unneeded gases from the patient & Sx suite.
- To deliver oxygen as the sole gas, as in CPR
For an anesthetic machine to perform its purpose as intended it must: (3)
- Deliver O2 at a controlled rate
- Vaporize a designated concentration of liquid anesthetic, mix anesthetic with O2, & deliver mixture to the patient.
- Remove exhaled gases from the patient, then dispose of the gases thru a scavenging system or recirculate them to the patient.
Word bank:
- Inhalation hose - Exhalation hose
- Connecting port - Pop-off valve
- Vaporizer - Flowmeter
- CO2 absorber canister - O2 tank
- Tank pressure gauge - Flush valve
- Reservoir bag - Port to ET tube
- Pressure reducing valve - To scavenger
- Inhalation valve - Exhalation valve
T/F: The oxygen source for an anesthetic machine is a localized moveable cylinder or a large centrally located source.
True
A full tank will read at ___psi
2200 psi
E tank & H tank
1. Size:
2. Attachment style:
3. Liters it holds:
E tank
1. Small
2. Portable
3. 660-700L
H tank
1. Large
2. Attached to wall
3. ~7000L
Tanks should always be ___ prior to surgery or oxygen emergency, and always ___ at the end of the day.
Remember, ___ will be fueled by an open oxygen source!
- Opened
- Closed
- Fires
The first pressure reducing valve is near the ___ source.
This valve reduces pressure leaving the tank & entering the machine to ___-___ psi.
At this low pressure, the gas flows thru the ___, which when opened, delivers a known amount of gas to the ___ and ___ ___.
Lower pressure ___ is now carried thru the source lines to the machine.
- Oxygen
- 40-45 psi
- Flowmeter
- Vaporizer & breathing circuit
- Gas
The flowmeter further reduces the pressure of gas to ___psi. This is close to ___ pressure and is well ___ by patients.
- 15 psi
- Atmospheric
- Tolerated
What does a flowmeter regulate?
How is it measured?
- Regulates how much O2 is entering the system & delivered to the patient
- Measured in L/min or mL/min
What is the function of the flush valve?
Allows a quick infusion of straight O2 into the breathing circuit
The flush valve should ___ be used on a ____ as the O2 pressure coming out of the machine is too ___ and can harm the patient.
Plus, these systems are already using a ___ O2 flow.
- Never
- Non-rebreather
- High
- High
What is the function of the vaporizer?
Hold liquid anesthetic and vaporize into a gas form that can be delivered in a controlled manner.
The vaporizer inlet is where O2 ___ the vaporizer to carry the ___ molecules to the patient.
The outlet is where the ___ and gas ____ the vaporizer to ___ the circuit.
- Enter
- Gas
- O2
- Leave
- Enter
When should you fill the vaporizer? How should you go about that?
- When the level is 1/2 to 1/4 remaining
- Make sure to close down the vaporizer in order to prevent contamination & open filling knob
Standard precision vaporizer is used with ___ pressure anesthetics. These ___ pressure anesthetics vaporize ___ and must be delivered at a ___ rate.
It compensates for ____, carrier gas flow ___, and back ___.
- High
- High
- Quickly
- Controlled
- Temp
- Rate
- Pressure
Non-precision vaporizers are an ____ vaporizer.
Only ___ pressure anesthetics can be used, those that vaporize ___, about __% concentration is the max that will reach carrier gas.
- Uncontrolled
- Low
- Slowly
- 4%
What are three factors that affect non-precision vaporizers?
- Temperature
- Gas flow
- Back pressure
Inspiratory valve is also called a dome, float, or ___ valve. It is designed to allow movement of ___ in only ___ direction.
As the patient inspires, the gases move thru the ___, thru the ___ tubing and delivered via the ___ ___ to the patient.
- Flutter valve
- Gases
- One direction
- Valve
- Breathing/corrugated
- ET tube
T/F: The inspiratory valve usually has a positive-pressure relief valve
False! It usually has a NEGATIVE-pressure valve
Why do inspiratory valves allow room air to enter the system?
The patient is trying to breath and the valve lets room air in because if the O2 tank runs out, instead of the patient suffocating, the machine allows the patient to breath room air.
- Safety valve allows patient to breath if the O2 supply runs out or is shut off
Expiratory valve work with ___ gas.
As the patient ___, the gases travel thru the ___ tubes thru this ___ valve.
- Expired
- Exhales
- Breathing
- Unidirectional
T/F: The movement of both inspiratory & expiratory valves is a good visual indicator of the patients respiration
True
Pop off valve functions (2)
- It can act as a vent when in the open position, it prevents build up of pressure.
- It can also be used to determine flow rate techniques.
- High flow rates need wide-open valve, lower flow rates can be used with it partially closed.
T/F: The only time the pop-off valve should be temporarily completely closed is when “bagging” a patient
TRUE
What is a manometer? Unit of measurement?
- Pressure gauge that measures pressure within the system. DOESN’T REGULATE!
- Indicator of pressure within a patients lungs - Measurement is cm of water (cm H2O)
The reading of a manometer should never exceed ___cm H2O.
The pop-off valve & manometer have a ___ relationship. The more the “pop-ff” is ___, the ___ the pressure reading on the manometer.
- 20cm H2O
- Direct
- Closed
- Higher
Rebreathing bag function & purpose (3)
- Bag will deflate as the patient inspires and inflate when the patient expires.
- Movement is a good visual indication of respiratory rate & quality.
- Allows for manual ventilation for the patient
How to “bag” a patient (3)
- Close the pop-off valve.
- Bag is squeezed to no more than 20cm H2O on manometer.
- Open pop-off valve
The bag stores excess ___ and provides back up quantities to be ___.
A bag should be ___ to ___ times the ___ volume.
- Gases
- Inspired
- 5 to 6 times
- Tidal vol
How is the tidal volume calculated?
10mL/kg of the body weight.
Round UP not down!
CO2 absorber is made up of what two materials?
What is the color change that occurs?
- Either sodasorb or baralyme
- White to purple after CO2 is absorbed
Scavenging System
1. Function
2. Passive
3. Active
- Tubing attached to the pop-off valve pass to an active charcoal canister.
- Passive
- Rely on gravity as anesthetic gases are the heaviest of expired gas. - Active
- Attached to the machine producing a vacuum that removes gases out of the building.
Rebreathing circuit
1. Function
2. Who can use it
3. Tube names
- Recirculation of some expired gases, & lower flow of oxygen.
- Patients weighing 10lbs+
- “Y” piece or Universal F
Non-rebreathing
1. Function
2. Who can use it
- No gases rebreathed. Req higher O2 flow to push gases to Pt. Less effort for lungs of a small Pt.
- Patients weighing less than 10lbs or respiratory compromised Pt
