Monitoring Flashcards
DISS
diameter index safety system
PISS
Pin Index Safety System
Diameter Index Safety System
connects to pipeline
Pin Index Safety System
connects to cylinders
pressure in gas pipeline
50 psi
Pressure in E-cylinder
1900-2200 psi
(745 if N2O)
If the oxygen cylinder valve is opened and there also pipeline pressure, will the oxygen from the O2 cylinder be used or oxygen from the pipeline?
cylinder (45 psig) < pipeline (50 psig)
gas will be taken from pipeline if both are open
Ohmeda ventilator
pneumatic
100% oxygen used for drive gas
North American Drager ventilator
pneumatic
33% Oxygen entrained with room air via venturi system
Datex fail-safe
pressure shut-off valve (PSSV)
fail-safe
prevents delivery of hypoxic mixture
PSSV
Pressure Sensor Shut-off Valve
Pressure Sensor Shutt-off Valve
when O2 supply is less than 20 psig, the valve closes and shuts off other gases
- upstream from 2nd stage regulator
- Datex
Draeger fail safe
O2 Failure Protection Device and O2 Ratio Monitor Controller (ORMC)
OFPD
Oxygen Failure Protection Device
O2 Failure Protection Device (OFPD)
gradually reduces other gases until O2 supply is below 12+/- 4 psig
- based on proportioning
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ORMC
O2 Ratio Monitor Controller
O2 Ratio Monitor Controller (ORMC)
O2 resistor is 3-4x that of N2O resistor, if diaphragm falls, a hypoxic mixture can be given
- Drager
- similar to link 25
If there is a loss of oxygen pipeline pressure, which flow meter bobbin will go down first, oxygen or nitrous?
Nitrous
assuming fail-safe is working properly
What kind of leaks do you test for with a positive pressure leak test?
leaks between CGO and patient’s circuit
What is the most common cause of leaks inside the machine (prior to the common gas outlet)?
partially open filler ports for the vaporizers
What is the dead space in the circle system and what valves minimize this dead space?
Dead space is bidirectional flow. The inspiratory and expiratory valves help prevent two way flow/dead space
What happens if you have tear in the bellows?
- bellows wont rise
- anesthetic agents may be diluted by drive gas
- FGF will be more diluted with O2
Why is the manual breathing bag located on the expiratory limb and not on the inspiratory limb of the circle system?
To prevent rebreathing of expired gas. Exhaled gas goes to manual rebreathing bag and through the CO2 absorber before returning to the inspiratory limb in the circle breathing system. Expiratory one way valve prevents expired gas in expiratory limb from going back to patient.
how do you change a semi-closed system to a closed system?
remove scavenging
Why do you need a negative pressure relief valve?
The negative pressure relief valve prevents negative pressure in the scavenging system from being applied to the patient.
- Negative pressure can occur when there is maximum suction and the APL valve is open or negative pressure relief valve fails.