Anesthesia Machine Flashcards
what kind of power back up is required of an anesthesia machine
back up battery lasts 30 min
what are the three kinds of anesthesia alarms
high, medium, low priority
how long can a high-priority alarm be silenced for
no more than 2 minutes
what alarms and monitors must be automatically enabled
breathing circuit pressure
oxygen concentration
exhaled volume or carbon dioxide
what must disconnect alarms be based on
low pressure
exhaled volume
carbon dioxide
a high-priority pressure alarm must sound for what 4 reasons
user-adjusted limits are exceeded
continuing high pressure is sensed
negative pressure
low inspired O2
what are the required monitors for anesthesia machine
-exhaled volume
-inspired O2 with a high priority alarm with 30 seconds of oxygen falling below 18% (or set limit)
-oxygen supply failure alarm
-a hypoxic guard for less than 21% O2 if NO is used
-anesthetic vapor concentrator monitor
- pulse ox, blood pressure, ECG
-pressure in breathing circuit set to 125 cm water
-nondetachable or resistant to detachment electrical supply cord
what is the max pressure in the breathing circuit for alarm
12.5 kPa / 125 cm water
what vital monitors must be present on the anesthesia machine
pulse ox
blood pressure
ECG
what are required cylinder supplies of the anesthesia machine
-at least one O2 cylinder attached
-hanger yoke must be pin-indexed, have a leak resistant clamping device, filter, check valve, cylinder pressure gauge
-cylinder pressure regulators, must use pipeline gas as long as pipeline pressure is greater than 345 kPa (50 psi)
what must pipeline gas pressure be above for cylinders to not be used
345kPa (50 psi)
what are required components of an anesthesia machine related to flowmeters
-single control for each gas
-each flow control must be next to a flow indicator
-must be a uniquely shaped oxygen control knob
-valve stops to no damage to flowmeter
-O2 flow indicator is the right side of a flowmeter bank
-O2 enters the common manifold downstream of other gases
-an auxilliary O2 flowmeter is strongly recommended
-an oxygen flush is present capable of 35-75 L/min that does not proceed through any vaporizers
what flow must an oxygen flush be capable of
35-75 L/min
what are required components of an anesthesia machine related to vaporizers
-they must be concentration calibrated
-an interlock must be present (only one can turn on)
-liquid level must be indicated and designed to prevent overfilling
-keyed filler devices(recommendednotrequired)
-no discharge of liquid anesthetic occurs from the vaporizer, even at the maximum fresh gas flow
what are required components of an anesthesia machine related to the pipeline gas supply
-pipeline pressure gauge
-inlets for at least O2 and NO
-Diameter index safety system (DISS) protected
-in line filter
-check valve
what are the components of the electrical system of the anesthesia machine
master switch
power failure indicator
backup (battery) power
electrical outlets
what are components of the pneumatic system of the anesthesia machine
high-pressure system
intermediate pressure system
low pressure system
what does the master switch activate
pneumatic and electric functions
what components of the anesthesia machine run without power
O2 flush
suction
auxillary O2
what alerts the anesthesia provider of loss of power to the machine
power failure indicator
should high frequency surgical devices be connected to electrical outlets of the anesthesia machine
no
what are the boundaries of the high pressure system
received gases from cylinder till first stage pressure system
what does the first stage pressure system lower the pressure to
40-50 psi 40-60, multiple answers
what are the boundaries of the intermediate pressure system
from first stage regulator or pipeline system to flow controls or O2 flush valves
what is the pressure in the intermediate system
40-60 PSI or 40-50 or 16-55 so who knows
what are the boundaries of the low pressure system
from control valves to common gas outlet, vaporizers, flowmeters, and check valves
what part of the anesthesia system is the O2 flush valve part of
intermediate pressure system
where does gas of the high pressure system come from
cylinder
what is included in the high-pressure system
hanger yoke,
yoke block,
check valves
micron filter
cylinder pressure indicator (gauge)
pressure-reducing device (regulator)
what device prevents backflow
check valves
what device do you double check on a cylinder when you notice a leak
o ring/cylinder gasket
each hanger yoke must have a ______________ that displays the pressure of the cylinder supplied gas
pressure indicator/gauge
what is the role of a cylinder pressure regulator (aka first stage regulator)
-maintain constant flow with a change of supply pressure
-reduce the high and variable pressure of a cylinder to intermediate pressure
what is the pressure of the intermediate system
40-50 psi
if both pipeline and cylinder gases are being used which will the machine use
the higher pressure, so the pipeline, because the first stage regulator changes the tank pressure to 45 and the pipeline pressure should be 50
what is the pin index safety system (PISS) for oxygen
2,5
what is the pin index system system (PISS) for N2O
3,5
what is the pin index system system (PISS) for Air
1,5
what is the pin index system system (PISS) for CO2
1,6
what is the volume and pressure of an oxygen E-cylinder
2000 psi
660 L
what is the volume and pressure of an N2O E-cylinder
745 psi
1590 L
what is the weight of a full N2O cylinder
8.8 kg
what is the weight of an empty N2O cylinder
5.9 kg
when the pressure of an N2O E-cylinder starts to drop how many L are left
400L
what is the weight of N2O inside a full E-cylinder
2.9 kg (8.8 kg-5.9kg)
when do we replace an O2 cylinder on an anesthesia machine
1000 psi, 330 L
know how to do cylinder math ie if an O2 cylinder is half full and running at 3L/min how long will it last
110 minutes
what is included in the intermediate pressure system
-pipeline inlet connections
-pipeline pressure gauges (on the front of machine)
-pipleline pressure gauge/micron filter
-ventilator power inlet
-O2 pressure-failure devices
-second stage pressure regulators
-flush valve (O2)
-auxillary O2 flowmeter
-master switch
what is the specialized fitting system for the pipeline inlet connections
DISS diameter index safety system
what does each pipeline inlet connection contain to prevent backflow
check valve
what is present in each pipeline inlet connection to keep dirt and stuff out
100 micrometer filters
what happens when pipeline inlet filters become clogged
decreased gas flow
what is the color of oxygen
green
what is the color of air
yellow
what is the color of N2O
blue
how much pressure must the internal piping of an anesthesia machine be able to uphold
4x
what prevents the depletion of O2 supply from a cylinder so you dont deliver 100% anesthetic gases
oxygen pressure failure devices
what do oxygen failure safety devices (fail safe) do
shuts off/decreases/stops the flow of N2O and other gases if O2 supply decreases to below 25 psi
where is the fail safe located
upstream of flow control valves
what alarm sounds if oxygen falls below threshold (30psi)
oxygen supply failure alarm
what is the flow of the oxygen flush valve
35-75 L/min
what is the pressure system of the oxygen flush valve
intermediate
what are risks of the oxygen flush valve
accidental activation
internal leakage
sticking in ON position
Barotrauma
anesthesia awareness (dilutes anesthetics)
if activated during inspiration may cause very high pressures
where does the intermediate pressure system end
needle valves of the flowmeters (includes the valves)
where is the second stage reducing device in relation to N2O and O2 flow valves
upstream
what pressure does the second stage reducing device lower N2O to
26psi
what pressure does the second stage reducing device lower O2 to
14 psi (or 16 in book…)
what controls the rate of flow of gas through a flow indicator (flowmeter) by manual adjustment
flow control valve
what is the profile of the O2 flow control valve
fluted profile (for safety it must look and feel different from others)
what rotation of the flow control valves increases flow
counterclockwise
what rotation of the flow control valves decrease flow
clockwise
what is the boundaries of the low pressure system
downstream of flow control valves (flowmeters) to common gas outlet though circuit
what is included in the low pressure system
flowmeter tubes
vaporizers
outlet check valve
common gas outlet
flow meters are tapered with the smallest diameter at the
bottom
where does gas enter the flow meter
from the bottom
what are flow indicators made from
glass
where do you read a ball float in a flow meter
in the middle
where do we read a bobbin flow meter
top of float
what does the float stop prevent
indicator plugging the outlet for gas
why is the sequence of flow indicators important
improper flow indicator order can cause hypoxia (oxygen must be last ie far right)
where should oxygen be in the sequence of flow indicators
the most downstream (right)
what are the flow safety features for minimum O2 flow
minimum flow of O2 before other gases will flow
50-250 ml/min preset at factory
activated when master switch is turned on
what does the O2 ratio and proportion system keep oxygen % at
minium 25% flow
what causes O2 and N2O to turn together or disables the N2O until more O2 is dialed in
the O2 ratio and proportioning system
-may have mechanical or pneumatic linkages between N2O and O2
what is the mechanical link between the N2O and O2 flow meters called
link-25 proportion limiting control system (increased N2O increased O2)
what is the function of the auxiliary O2 flowmeter
-allows for connection of nasal cannula, face mask, ambubag when master switch is off
-used when machine malfunctions
what state does the flowmeter have the most innaccuracy
low flows
what causes float sticking in flowmeters
static electricity, dirt, debris
where is the vaporizer mounting device located
in the low pressure system between flowmeters and common gas outlet
do you tip a vaporizer
no
what receives all gases and vapors from machine and delivers them to patient through fresh gas supply
common gas outlet
what is a location of possible leak or disconnect
common gas outlet
what ensures that gas flows towards the patient in one breathing tube and away from the patient in another
unidirectional valves
what permits gas flow to patient during inspiration
inspiratory check valve
what permits gas flow from patient to rebreathing bag/scavenging system/and CO2 absorber
expiratory check valve
can the expiratory and inspiratory valve be open at the same time
no, only one valve open at a time
what does the APL valve do
located on the expiratory side of the circuit
-adjusted to provide varying pressure to patients resp efforts
-alters amount of common gas within breathing bag
what is another name for the pop-off valve
APL valve (adjustable pressure limiting valve)
during spontaneous respiration the APL valve is
fully open
during manual ventilation the APL valve is
partially open
during mechanical ventilation the APL valve is
isolated from the system
during manual ventilation, what determines the pressure at which you are bagging the patient
APL valve
what pressure does the APL valve determine
relief pressure
what measures the tidal volume delivered to the patient
spirometer
where is the spirometer located in the breathing circuit
expiratory limb
what measures the tidal volume intermittently delivered to patient from breathing circuit
spirometer
what principle measures minute and tidal volumes in the spirometer
turbine principle
what causes errors in spirometery
friction, water, condensation, debris
what is measured by the breathing circuit pressure gauge
the pressure between inspiratory and expiratory unidirectional valves,
measures airway pressure
what can causes changes in spirometry
usually changes in ventilator settings and changes in spontaneous breathing patterns
-can reflect circuit disconnect or equipment malfunction
what is the highest pressure read by the breathing circuit pressure gauge
PIP
what does PIP indicate about the lungs
compliance
what does an increased airway pressure from the breathing circuit pressure gauge tell us
worsened pulm compliance
increaced TV
obstruction in circuit
what does a decreased airway pressure from the breathing circuit pressure gauge tell us
improvement in pulm compliance
decreased TV
leak in circuit
what is the breathing bag of the anesthesia circuit
ventilator bellows
what are the two types of ventilator bellows
standing
hanging
where does ventilator bellows receive gases
ventilator power inlet
pressurized O2 from machine,
reservoir for gases
in standing bellows, where does the bellows move during expiration
upward
in standing bellows, where does the bellows move during inspiration
downward
in hanging bellows, where does the bellows move during inspiration
upward
in hanging bellows, where does the bellows move during expiration
downward
what alarm detects a drop in peak circuit pressure
disconnect alarm
what percent is the O2 sensor calibrated to
21
what disposes of gases that have been vented from breathing circuit
waste gas scavenging system
what can happen if the waste gas scavenging system indicator is outside of the green
gas could be vented into OR
what are the 4 components of the scavenging system
relief valve
tubing
interface
disposal line
how much alveolar gas does the circle system allow you to rebreathe
<1 L/min
what is wet soda lime composed of
80% calcium hydroxide Ca(OH)2
5% potassium hydroxide KOH
15% water
trace amounts of silica and clay
what does the silica and clay do in the soda lime
increases hardness and decreases dust formation
exhaled CO2 combine with H2O to create
carbonic acid
CO2 + H2O -> H2CO3
what is the fast reaction formula for soda lime
H2CO3 + 2NaOH -> Na2CO3 + 2H2O + heat
what is the slow reaction formula for soda lime
Na2CO3 + Ca(OH)2 -> CaCO3 + 2NaOH
what are the reactant products of CO2 absorbent
heat, water, calcium carbonate
how much CO2 is absorbed by absorbant
14-23 L CO2/100 g absorbant
what is the mesh size of CO2 absorbant
4-8 mesh
what percent of absorbant is used before color change occurs
50-70%
does a mesh size of 1-2 have more or less surface area
less
the larger the granules the __________ the resistance
less
the smaller the granules the ___________ the surface area
greater
an open circuit system has _______ reservoir and ______ rebreathing
no
no
what is A
flowmeter
what is B
flush button
what is C
vent bellows
what is D
common gas outlet
what is E
absorber
what is F
brake
what is G
system switch
what is H
vaporizors
what is i
ventilator
what is A
gas supply modules
what is B
sensor interface panel
what is C
waste scavenging interface valve
what is D
absorber
what is A
right angle connector
what is B
Y connector
what is C
expiratory unidirectional valve
what is D
APL valve
what is E
reservoir
what is F
CO2 absorber
what is G
fresh gas inlet
what is structure H
inspiratory unidirectional valve
what is i
flexible breathing tube
what goes through this
oxygen 2,5
what goes through this
nitrous 3,5
what goes through this
air 1,5
what goes through this
CO2 1,6
what goes through this
oxygen 2,5
what goes through this
N2O 3,5
what goes through this
air 1,5
what goes through this
CO2 1,6
what is 1
check valve
what is 2
N2O pipeline supply
what is structure 3
pressure regulator (decreases from high to intermediate pressure)
what is 4
fail safe valve (only open when oxygen is flowing at 25 psi or greater)
what is 5
second stage pressure regulator (decreases intermediate pressure, maintains constant flow, no fluctuations)
what is 6
vaporizers (only one at a time)
what is 7
rotameter flowmeter
what is 8
needle valve for flowmeter
what is 9
pressure relief valve
what is 10
outlet check valve
what is 11
common gas outlet
what is 12
breathing circuit to patient
what is area highlighted by 13
low pressure
what is 14
O2 flush valve
what is 15
second stage O2 pressure regulator
what is 16
O2 supply low pressure alarm
what is 17
auxiliary O2 flowmeter
what is 18
auxiliary O2 DISS connector
what is 19
anesthesia ventilator driving gas circuit
what is 20
line pressure gauge
what is 21
O2 pipeline supply
what system is N2O molecule A in
high pressure
what system is N2O molecule B in
intermediate
what system is N2O molecule C in
low
what system is oxygen molecule E in
intermediate
what system is oxygen molecule D in
low
what system is oxygen molecule F in
intermediate
what system is oxygen molecule J in
intermediate
what system is oxygen molecule G in
intermediate
what system is oxygen molecule H in
intermediate
what system is oxygen molecule I in
high
pressure system breakdown
what goes in structure 5
to machine
what goes in 1
wall supply
what is structure 2
DISS fitting
what is structure 3
valve seat
what is 4
check valve
what is A
Cylinder gasket/ O ring
what is B
T handle
what is C
pipeline inlet
what is D
cylinder wrench
what is 1
N2O flow of O2 failsafe valve
what is 2
valve return spring of O2 failsafe valve
what is 3
valve of O2 failsafe valve
what is 4
valve seat of O2 failsafe valve
what is 5
thrust pin of O2 failsafe valve
what is 6
piston of O2 failsafe valve
what is 7
diaphragm of O2 failsafe valve
what is 8
O2 pressure at 25 psig or higher for O2 failsafe valve
what is A
T handle
what is B
valve stem
what is C
cylinder valve
what is D
gasket
what is E
to machine
what is F
hanger yoke check valve
what is G
PISS System
what is H
gas outlet
what is 14
inspiratory check valve
what is 10
CO2 absorber
what is 2
sevo vaporizor
what is 12
auxiliary common gas outlet
what is 4
oxygen inlet
what is 7
air inlet
what is 1
N2O pressure gauge
what is 2
N20 pressure regulator
what is 3
closed circuit outlet
what is 4
ventilator outlet
what is 5
O2 flush
what is 6
fresh gas outlet
what is 7
O2 pressure regulator
what is 8
O2 pressure gauge
what is 9
for low pressure alarm system
what is 1
gas outlet to manifold
what is 2
float stop
what is 3
tapered flow tube
what is 4
float
what is 5
float stop
what is 6
valve seal
what is 7
O2 inlet (14/16 psi for O2)
what is 8
needle
what is 9
valve stops
what is 10
flow control knob (fluted for O2)
what is this system
Link 25 Proportioning System
what is 1
N2O gear
what is 2
kick-in tab on gear
what is 3
O2 gear
what is 4
O2 knob and collar
what is 5
stop screw on collar
what is 6
chain
what is A
vaporizer A
what is B
to common gas outlet
what is C
manifold bypass
what is D
from flowmeters
what is E
vaporizer B
what is A
stationary vane (channels gas into spiral motion)
what is B
rotating vane of spirometer
