AGM Need to Know Flashcards
What AACN standard is pertinent to the anesthesia gas machine?
Standard 6
When does the anesthesia gas machine check need to be completed?
every morning without fail, abbreviated check between cases
What does SPDD stand for?
Supply, Processing, Delivery, Disposal
Why are some gases stored as liquids instead of gases?
1 liter of liquid O2 is equal to 860 liters of gas so it also us to optimize space
What is a floating valve?
a floating valve is a unidirectional valve in the circle system
it opens and closes with pressure and moves in direction of gas flow
The critical temperature of gas determines
how it will be stored as a liquid or as a gas
O2 & air are stored as gases; nitrous oxide is stored as a liquid
The pressure gauges on the front of the machine are also known as
Bourdon pressure gauges
Describe the pin location for air, nitrous oxide, and oxygen for the pin index safety system
air: 1 & 5
Nitrous oxide: 3 & 5
Oxygen: 2 & 5
What makes up Wood’s Metal?
Bismuth, lead, Tin, Cadmium
Wood’s metal is a safety mechanism where when certain temperatures are experienced in the OR, it will melt to prevent a tank from exploding
The markings on the tank indicate (green, yellow & red)
green diamond- indicates its a non-flammable gas
yellow- oxidizer
red- flammable gas
The federal food, drug, and cosmetic act is responsible for
regulating medical gases contained in cylinders
sets standard for potency/purity
The Department of Transportation is responsible for
cylinder design, construction, testing, marking, handling, filling, transportation
The Compressed Gas Association is responsible for
sets standards on safe practice
The National Fire Protection Association is responsible for
location, construction, installation of bulk systems
The critical temperature of nitrous oxide is
36.5 degrees C
Name the color, pressure, capacity & pin position for oxygen
green, 1900 PSI, 660 L, pin position 2,5
Name the color, pressure, capacity & pin position for nitrous oxide
blue, 745 PSI, 1590 L, pin position 3 & 5
Name the color, pressure, capacity & pin position for air
yellow, 1900 PSI, 625 L, pin position 1 & 5
Oxygen has critical temperature of
-118.8 degrees Celsius (below room temp.)
Utilize Boyle’s Law to calculate how much time you have before having to change your tank
set up a proportion using P1V1=P2V2
What is part of the high pressure system?
Exposed to cylinder pressure; hanger yoke, yoke block with check valves, cylinder pressure gauge and cylinder pressure regulators
What is part of the intermediate pressure system?
exposed to pipeline pressure ~50 psi; includes pipeline inlets, check valves, pressure gauges, ventilator power inlet, oxygen pressure-failure devices, flowmeter valve, oxygen second stage regulator; flush valve
What is part of the low pressure system?
distal to flowmeter needle valve; flowmeter tubes, vaporizers, check valves, common gas outlet
Describe the purpose of the failsafe valve
The system is designed to prevent unintentional delivery of a single gas other than oxygen to the flow control valves but if adequate pressure remains in the system then the valve will remain open; if there’s a malalignment and it is not really oxygen, then it will allow the valve to remain open and deliver a gas that is not O2… fail safe, not fail proof
Safety mechanisms in relation to the flowmeters include:
color and touch coded (oxygen is fluted)
What laws are pertinent to the Thorpe tube?
Bernoulli, Pouiselle’s, and Ohm’s law
Vapor pressure increases
with temperature
List the vapor pressure of isoflurane
239 mmHg
List the vapor pressure of halothane
243 mmHg
List the vapor pressure of Enflurane
175 mmHg
List the vapor pressure of sevoflurane
170 mmHg
List the vapor pressure of desflurane
669 mmHg
When you add vaporized anesthetic agent
the total volume exiting the chamber is greater than the volume entering the chamber
When a certain volume of carrier gas flows from machine into vaporizing chamber over a certain period of time
that same volume of carrier gas exits the chamber over the same period of time
If a higher VP agent is placed in a vaporizer of a lower VP agent,
concentration of agent delivered will be HIGHER than dialed setting and vice versa
The Tec 6 vaporizer is
a gas/vapor blender; not variable bypass
The issue with desflurane is
it is boiling at room temperature; the Tec 6 vaporizer avoids the problem by heating desflurane above its boiling point
On the Tec 6 vaporizer, the internal battery is
alarm only; it has to be electrically powered in order to use; internal battery is for alarms only and will not support the heating element so if you lose power you have to change your volatile anesthetic
The warm-up (amber) light on the Tec 6 means
the machine is in warm-up mode and we cannot turn the control dial
The operational (green) light on the Tec 6 means
the vaporizer is functional
The no output (red) light on the Tec 6 means
the vaporizer can’t add agent vapor to gas flow due to lack of agent, tilting, or malfunction
The low agent light on the Tec 6 means
<250 mL of agent in sump
The alarm battery low (amber) on the tec 6 means
low battery voltage- battery only powers alarms, not vaporizers
The five tasks that oxygen is responsible for includes
proceeds through flowmeter, supplies O2 flush valve, activates fail-safe mechanism, activates low oxygen pressure alarm, drives the ventilator
Describe an open circuit
An open circuit does not have a reservoir bag, does not permit rebreathing and examples include open drop, nasal cannula, or face masks
Describe a semi-open circuit.
A semi-open circuit includes a reservoir bag, does not allow rebreathing, and examples include nonrebreathing circle or circle at high FGF (>VE)
Describe a semi-closed circuit
A semi closed circuit includes a reservoir bag, allows for partial rebreathing, and an example is circle at low FGF (
Describe a closed circuit.
A closed circuit includes a reservoir bag, has complete rebreathing, and an example is circle (with pop-off valve [APL] closed)
What is the purpose of the APL valve?
The APL valve is used to regulate the pressure in the circuit during MANUAL ventilation; it is bypassed in mechanical ventilation mode
(adjustable pressure limiting valve)
A ventilator hazard is the failure of
emergency O2 supply or the E-cylinder
Granule sizes includ
4 to 8 mesh which means there are 4 quarter inch openings per linear inch
must compromise between resistance to airflow and surface area for absorptive capacity
In a nonrebreathing system or semi-open system,
we have to make sure fresh gas flow is high enough or you’ll have rebreathing
Describe the Mapleson A circuit.
The Mapleson A circuit is a nonrebreathing if FGF> alveolar ventilation; the overflow valve opens during expiration when maximum pressure is reached
Order as follows: FGF, bag, tubing, expiratory valve & mask
Describe the Mapleson B circuit.
The Mapleson B circuit includes fresh gas inlet and overflow valve closer together to the patient to decrease rebreathing; requires FGF 2-2.5x’s minute ventilation
bag, tubing, FGF, expiratory valve, bag mask
Describe the Mapleson C circuit.
Shorter expiratory limb than Mapleson B; requires FGF 2-2.5 x’s minute ventilation
Bag, tubing, FGF, expiratory valve, bag mask
Describe the Mapleson D circuit.
Fresh gas inlet and overflow valve opposite Mapleson A; requires FGF 2-3 x’s minute ventilation
bag, tubing, FGF, expiration valve, mask
Describe the Mapleson E circuit.
Valveless and bagless (basically a T-piece); expiratory limb must be > patient’s tidal volume to prevent entrainment of room air; FGF 3x’s minute ventilation to prevent hypercarbia
No expiratory valve, NO bag
Tubing, FGF, mask
Describe the Mapleson F circuit
Jackson-Rees modification of the Mapleson D; requires FGF 2-3x’s minute ventilation; minimal dead space/low resistance
when using controlled ventilation know the different characteristics of Mapleson A, B, C, D, & E
expiratory valve, bag, tubing, FGF, mask
