Gas Machine Flashcards
The Anesthesia Machine Definition:
A device which delivers a precisely-known but variable gas mixture, including anesthetizing and life-sustaining gases.
What’s the difference between an Anesthesia gas machine & an ICU ventilator?
1.Manipulation of mix of gases
•Washin/out N2, O2, N2O, agents
•Humidification
•Rebreathing and CO2 removal
2.Monitoring of gas composition (because of #1)
3.Manipulation of fresh gas flow
•“low flow” anesthesia
4.Adaptability
•smallest neonate to largest adultWhat is the gas machine ASTM standard?
American Society for Testing and Materials F1850 workstation standard- determines what should be on every anesthesia workstation
Normal working pressure of gas machine?
50 psi
What is the O2 flush flow in L/min?
35-75L/min (huge)
What is the National Institute for Occupational Safety and Health (NIOSH) standard for Wast Anesthesia Gases (WAGs)?
- 2 ppm halogenated agents (0.5 ppm with nitrous oxide)
- 25 ppm nitrous oxide
What are the tube sizes for scavenger system hoses?
19 or 30 mm
What are the tube sizes for the breathing circuit?
22 mm
What are the tube sizes for ETT or CGO (common gas outlet)?
15mm
What are the five tasks of O2 in the gas machine?
- ventilator
- flush valve
- oxygen pressure failure alarm
- “fail safe” (pressure sensor shutoff valve)
- flowmeters
What components are part of the high pressure system?
- Hanger Yoke
- Yoke block with check valve
- Cylinder pressure gauge
- Cylinder pressure regulators
N&P pg. 244
What parts of the gas machine are part of the low pressure system?
- Flowmeter tubes
- Vaporizers
- Check valves (if present)
- Common Gas outlet
N&P pg. 244
What is the ultimate destination of gases?
The scavenging system
What is the pipeline gas source?
It is liquid O2 converted to gas and supplied to hospital pipelines at 50 psi
What is the DISS?
Diameter index safety system- prevents cross connection of gases by designating different size connections for each gas
What is present at the pipeline inlet?
- Filter
- Check valve
- pressure gauge
What does the check valve do?
ensures unidirectional forward flow so that a machine running on cylinder supplies with the hose disconnected a the wall outlet does not leak
What are some pipeline source hazards?
- Unexpected contents- bacteria, viral, particulate
- Inadequate or (excessive) pressure
- Unexpected contents
What would alert you to inadequate pressure?
- Flowmeters drop, bellows drop, low pressure alarms
- To correct: disconnect hose from wall and open O2 cylinder fully, Don’t use mechanical vent and bag manually
What might indicate unexpected crossover of gases?
- Decreasing FiO2 in spite of unchanged O2 flow
- Disconnect hose from wall and open cylinder fully
When should cylinders be opened?
Only when being checked or pipeline supply is not available
What is the PISS?
Pin index safety system- the holes mate with pins in the yoke which point to where the cylinders are attached. It is a means of preventing misconnections
How can the PISS be defeated?
if pins are missing, removed, or if more than one washer is used
What is the hanger yokes function?
- orients cylinders
- provided unidirectional flow
- ensures gastight seal
