Anesthesia Gas machine Flashcards
High Pressure components
Hanger Yoke
Yoke block w/ check valves
Cylinder pressure gauge
Cylinder pressure regulator
Intermediate Pressure components and psi
Begins at pipeline and ends at flowmeter valves
pipeline inlets
pressure gauges
O2 pressure failure device
O2 second stage regulator
O2 flush valve
Ventilator power inlet
Flowmeter valves
Low Pressure components
Flowmeter tubes (Thorpe)
Vaporizers
Check valve
Common Gas outlet
What does the low-pressure leak test assess?
the integrity of the low-pressure circuit from flowmeter valves to common gas outlet
High pressure leak test assesses the integrity of the….
low-pressure system and the breathing circuit
What are the 5 Tasks of O2 in the SPDD Model
- O2 pressure alarm
- O2 pressure failure devices
- O2 Flowmeter
- O2 Flush valve
- Ventilator drive gas
What does the PISS prevent?
Connecting the wrong cylinder to the anesthesia machine
PISS configurations (Air, O2, Nitrous Oxide)
Air = 1, 5
O2 = 2, 5
Nitrous = 3,5
What does the DISS system prevent?
Wrong gas hose connected to AGM
Cylinder Pressure of Air, O2 and NO2
Air = 1,900 psi
O2 = 1,900 psi
Nitrous Oxide = 745 psi
Max Volume of cylinders
Air = 625 L
O2 = 660 L
Nitrous Oxide = 1,590 L
Equation for how much O2 is in cylinder
Tank capacity (L) / Full tank pressure (psi)
X
Contents remaining (L) / Gauge pressure (psi)
How long will tank last? (equation)
Contents remaining (L) / FGF rate (L/mnin)
=
Minutes before tank expires
Oxygen pressure failure device (failsafe) will not….
WILL NOT alarm with O2 pipline crossover (measures pressure, NOT O2 concentration)
Oxygen pressure failure device (failsafe) will….
Will alarm when O2 tank is depleted, drop in O2 pipeline pressure, or dissconnected O2 hose
How to calculate FiO2
How to calculate O2 Flow Rate (L/min)
Add 4% for each liter after 1L being 24% to a max of 44% (6L)
To ensure precise vaporizer output, the desflurane vaporizer heats the liquid anesthetic to ______ and __________.
39 C
pressurizes it to 2 atmospheres
The Tec 6 vaporizer does not ________.
does not compensate for changes in elevation
A ________ requires a higher setting on the dial of the Tec 6 vaporizer.
Lower ambient pressure (higher altitude)
A _________ requires a lower setting on the dial in a Tec 6 vaporizer.
higher ambient pressure (hyperbaric oxygen tank)
What is the FINAL defense against delivery of a hypoxic mixture?
Oxygen Analyzer!!!
-its the only device that measures O2 concentration
Variable bypass method of vaporization?
Flow over
Tec 6 Desflurane method of vaporization?
Gas/Vapor blender (heat generates vapor that is injected into the fresh gas)
Steps if you have O2 pipeline failure.
- turn on O2 cylinder and disconnect pipeline O2 supply
- verify if O2 concentration is increasing, IF NOT, then ventilate the pt w/ ambu bag connected to a DIFFERENT O2 tank (you will also need to convert to a TIVA(you no longer have gas since you are no longer using the AGM)
Oxygen flush valve O2 flow
35-75 L/min
Oxygen flush valve O2 pressure
50 psi
The mechanical spill valve is ________ during the inspiratory phase.
Pressing the O2 flush during inspiratory phase will…….
Closed!
transfer this pressure to pts lungs …… BAROTRAUMA!
Ascending bellows _______ during expiration.
Rise
-Safer since if there is a circuit disconnect they will not continue to rise and fall.
Descending bellows _______ doing expiration.
Fall
VCV setting
preset TV over a predetermined time
-Fixed = TV, inspiratory flow rate and inspiratory time
Variable= PIP
PCV setting
-preset inspiratory pressure over a predetermined time
Fixed = PIP and inspiratory time
Variable = TV and inspiratory flow
T-burg will ______Vt.
decrease from decreased compliance
When is PCV better than VCV?
1st and 2nd most common causes of low pressure in circuit?
- circuit disconnect
- co2 absorbent canister has poor seal or defective
Semi-open breathing circuit
FGF>minute ventilation
semi-closed breathing circuit
FGF< minute ventilation
Most common circle system related causes of rebreathing
-Incompetent unidirectional valve
-Exhausted CO2 absorbent
Malfunction of unidirectional valves = ?
the space between the y-piece and the valve to be dead space (risk of hypercarbia)
Best circuit for spontaneous ventilation? Worst?
Mapleson A (B is the worst)
Best circuit for controlled ventilation? Worst?
Mapleson D (A is the worst)