Gas Anesthesia Machine Flashcards
what are the two compressed Gas Cylinders?
Green Tank: Contains Oxygen
Blue Tank: Contains Nitrous Oxide
How do you read the oxygen gas cylinder?
Pressure gauge reads 2,200 psi when full
Reading is proportional to amount of oxygen remaining in the tank
Define the function of the gas anesthesia machine component: Regulator
Reduces the oxygen line pressure to 50 psi
How do you read the nitrous oxide gas cylinder?
Pressure gauge reads 750 psi when full
Reading begins to fall only after 80% nitrous oxide has been depleted therefore it is not proportional with what remains in the tank
Define the function of the gas anesthesia machine component: Flow Meter
Controls the amount of oxygen entering the anesthetic circuit
what is the oxygen flow rate formula for semiclosed rebreathing systems?
3(body weight in kg x 10)=__ml/min
Define the function of the gas anesthesia machine component: Oxygen Flush Valve
Delivers oxygen directly to the anesthetic circuit bypassing the flow meter
what is the oxygen flow rate formula for a non-rebreathing system?
body weight in kg x 300=__ml/min
Define the function of the gas anesthesia machine component: Vaporizer
Liquid anesthetic is stored within its chamber.
Oxygen passes through this chamber & pics up vaporized anesthetic molecules & carries them to the patient.
Define the function of the gas anesthesia machine component: Unidirectional Valves
Allow flow of gases in only one direction
Define the function of the gas anesthesia machine component: Breathing Tubes
Serve to transport gases to and from the patient
Define the function of the gas anesthesia machine component: Rebreathing Bag
Used as a reservoir of gases to ventilate the animal when necessary.
Should be kept 1/3 to 2/3s full during an anesthetic procedure.
How are rebreathers bag size determined ?
Body Weight.
<15lbs = 1L
15-40lbs = 2L
40-120lbs = 3L
120-300lbs = 5L
>300lbs = 35L
Define the function of the gas anesthesia machine component: Carbon Dioxide Absorber
Contains soda lime (CaOH) or barium hydroxide lime(BaOH) granules.
Filters out carbon dioxide (CO2) particles from the patients exhaled gases.
Define the function of the gas anesthesia machine component: Pressure Relief Valve (Pop Off Valve)
Acts to release excess pressure that builds up within the patients breathing circuit.
Adjusted to maintain an adequately filled rebreathing bag in a semiclosed rebreathing system
Define the function of the gas anesthesia machine component: Scavenger System
Captures waste anesthetic gases escaping through the pop off valve
Define the function of the gas anesthesia machine component: Breathing Circuit Pressure Gauge
Monitors the pressure within the breathing circuit.
Used when ventilating the patient.
List the gas anesthesia machine set up steps:
- Connect the Oxygen Line
- Connect the drop-down scavenging system line
- Check the liquid anesthetic reservoir in the vaporizer to see if it needs to be filled
- Check the carbon dioxide absorbing granule canister to make sure they are fresh
- Connect breathing tubes and rebreathing bag
- Pressure test your breathing system:
– close the pressure relief valve & plug the patient-end of the breathing tube w/ the palm of your hand
– fill the breathing system w/ oxygen using the flush valve or the flow meter but do not pressurize the breathing system
– squeeze the rebreathing bag to create a pressure of 20 cm of water in the breathing system
Check for air leaks or rapid deflation of the rebreathing bag–> This should not happen! - Determine the appropriate oxygen flow rate for your animal and turn the oxygen on before connecting the animal to the breathing tubes
Gas Anesthesia Machine Take-Down Procedure
- Turn off oxygen flow meter at end of anesthetic procedure
- Open the pressure relief valve
- Squeeze the rebreathing empty of gases
- Disconnect the animal from the breathing tubes
- Disconnect the breathing tubes and rebreathing bag from the gas anesthesia
machine - Disconnect the gas anesthesia machine from the drop-down oxygen line
- Disconnect the gas anesthesia machine from the drop-down scavenging system line
- Press and hold the oxygen flush valve to release the air pressure w/in the gas
anesthesia machine - Record time of use on carbon dioxide absorbing granule canister
The flow rate for a semiclosed rebreathing system is calculated using what formula?
3 (body weight in kg. X 10) = ? ml/min
the flow rate for a nonrebreathing sytem is calculated using what formula?
Body weight in kg. X 300 = ? ml/min
Minimum flow rate for small animals is always?
500 ml/min
Rebreathing bags should be how full during a procedure?
1/3 to 2/3 Full
How do you size a Rebreathing bag?
By Weight.
<15 1bs. = 1 L
15-40 lbs. = 2 L
40-120 lbs. = 3 L
120-300 1bs. = 5 L
>300 lbs. = 35 L
Anesthetic Breathing Systems function
is to deliver fresh anesthetic gases to the patient and removal of exhaled carbon dioxide from the patient.
Rebreathing System
Allow the rebreathing of exhaled gases minus the carbon dioxide
Rebreathing system benefits
- Low oxygen flow rates can be used
*Ventilation is readily observed and controlled by rebreathing bag
*Minimal heat loss and airway drying
Nonrebreathing System
Allow minimal or no rebreathing of exhaled gases
Norman Mask Elbow (Mapleson F System)–
Fresh gas enters breathing tube where patient is attached, exhaled gases exit through rebreathing bag
