Anesthesia Machine and Breathing Systems – Flashcards
Unlock all answers in this set
Unlock answersquestion
anesthesia machine consists of
answer
-anesthesia machine -vaporizers -ventilator -breathing system -scavenging system -monitors
question
anesthesia machine has evolved into a complex _______, _________, and ___________ multicomponent workstation
answer
electrical, mechanical, and pneumatic
question
master switch
answer
main power that activates both pneumatic and electrical functions
question
power failure indicator
answer
visible or audible alarm when there is a loss of power
question
reserve power
answer
battery back up during power outage
question
electrical outlets
answer
intended to power monitors and other devices. should not plug in anything else (i.e. bair hugger)
question
when circuit breakers are activated, the electrical load should be
answer
reduced
question
data communication ports are used to?
answer
communicate between machine and monitors
question
what are the 3 systems of pneumatic system
answer
1. high-pressure 2. intermediate pressure 3. low pressure
question
where does high pressure system receive gas from?
answer
cylinders at high variable pressures
question
high pressure system _________ those pressures to lower, more constant pressure suitable for use in machine
answer
reduces
question
hanger yoke functions to
answer
-orient and support the cylinder -provides gas-tight seal -ensures a unidirectional gas flow
question
parts of hanger yoke
answer
1. body 2. retaining screw 3. nipple 4. washer 5. filter 6. check valve assembly 7. index pins
question
body of hanger yoke
answer
principle framework and supporting structure
question
retaining screw of hanger yoke
answer
tightens cylinder in the yoke
question
nipple of hanger yoke
answer
through which gas enters the machine
question
washer of hanger yoke
answer
helps form seal between cylinder and yoke
question
filter of hanger yoke
answer
removes particulate matter to prevent it from entering machine
question
check valve assembly of hanger yoke
answer
-ensures unidirectional gas flow through the yoke -prevents gas from exiting the machine -allows an empty cylinder to be replaced without losing gas
question
index pins of hanger yoke
answer
prevent attaching on incorrect cylinder PIN index safety system (PISS)
question
there are ______ on cylinder valves
answer
holes
question
_______ on the yoke are positioned to fit into holes
answer
pins
question
unless the_____ and _____ are aligned, the port will not seat
answer
pins and holes
question
there must be a ________ _________ that displays the cylinder pressure for each gas
answer
pressure indicator
question
where must cylinder pressure indicator gauge be located?
answer
on front of machine
question
gauges are required to be calibrated in?
answer
kilopascals (kPa) or pounds per square inch (psi)
question
most machines will show ______ and _______ pressures
answer
pipeline and cylinder
question
full o2 cylinder has what pressure?
answer
1900 psi
question
a full N2O cylinder has what pressure?
answer
745 psi
question
pressure regulators function to?
answer
reduce the high and variable pressure found in the cylinder to a lower, more constant pressure suitable for the anesthesia machine
question
a _________ ____________ is required for each gas
answer
pressure regulator
question
how are pressure regulators set?
answer
preset at the factory
question
flow from cylinder cannot exceed what when pressure in pipeline system is 50 psi?
answer
10 ml/min
question
how do you prevent cylinder pressure from exceeding 10 ml/min when pressure in pipeline system is 50 psi?
answer
by keeping the pressure delivered by the regulator lower than the pipeline
question
intermediate pressure system receives gasses from?
answer
the pressure regulatory on the pipeline inlet to the anesthesia machine
question
components of intermediate pressure system
answer
1. master switch 2. pipeline inlet connections 3. pipeline pressure indicators 4. piping 5. gas power outlet 6. o2 pressure failure devices 7. o2 failure safety device 8. o2 supply failure alarm 9. o2 flush 10. flow adjustment control
question
master switch on intermediate pressure system
answer
pneumatic component
question
entry point for gases from pipelines on intermediate pressure system
answer
pipeline inlet connections
question
machines have _____, ______ , and _____
answer
oxygen, N2O and air
question
pressure on pipeline pressure indicators for intermediate pressure system should be
answer
50-55 psi
question
gas power outlet functions as
answer
a source of driving gas for ventilator *modern machines do NOT have this
question
function of o2 pressure failure devices
answer
shut off supply of gases other than o2 or alarm when o2 pressure falls to dangerous level
question
function of o2 failure safety device
answer
whenever o2 supply pressure falls below manufacturer's minimum, the delivered o2 concentration shall not decrease below 19% of common gas outlet
question
o2 supply failure alarms when?
answer
o2 supply pressure falls below 30 psi, at least a medium priority alarm begins within 5 seconds and is not possible to disable it
question
o2 flush receives o2 from?
answer
the pipeline inlet or cylinder pressure regulator and directs a high unmetered flow directly to the common gas outlet
question
flow of o2 flush is
answer
35-753ml/min
question
caution with o2 flush
answer
can cause barotrauma if pushed constantly
question
function of flow adjustment control
answer
regulate flow of o2, air, and other gases to the flow indicators
question
types of flow adjustment control
answer
2 types: 1. mechanical 2. electrical
question
mechanical flow adjustment control
answer
controls rate of gas flow through its associated flowmeter
question
electrical flow adjustment control
answer
electronically activated flow control devices can be used to alter gas flows
question
low pressure system of pneumatic system has pressure that is
answer
slightly above atmosphere and variable depending on flow from flow control valves, presence of back pressure devices, and back pressure from breathing system
question
components of low pressure system
answer
1. flowmeters 2. auxillary o2 flowmeter 3. hypoxia prevention safety device 4. mandatory minimum o2 flow 5. unidirectional valve 6. pressure relief device 7. common (fresh) gas outlet 8. vaporizers
question
flowmeters indicate
answer
the rate of flow of gases passing through them
question
flowmeters usually have a ______ or _______ which is free moving device within the tube
answer
float or bobbin
question
flowmeter sequence is important in preventing what?
answer
hypoxia (o2 is placed on right side)
question
auxillary o2 flowmeter is
answer
self-contained with its own flow control valve, flow indicator (ball) and outlet
question
max auxillary o2 flowmeter
answer
10L/min
question
hypoxia prevention safety device functions to
answer
prevent delivery of a hypoxic mixture
question
mandatory minimum o2 flow is
answer
minimum of 50-250 ml/min flow of o2 before other gases will flow
question
can a patient be hypoxic on 100% o2?
answer
yes if they aren't getting enough flow
question
unidirectional valve is located?
answer
between vaporizers and common gas outlet upstream of where the o2 flush flow joins the fresh gas flow
question
unidirectional valve functions to
answer
minimize the effects of positive pressure from the breathing system being transmitted back into the machine
question
where is pressure relief device located
answer
near the common gas outlet to protect machine from high pressures
question
function of pressure relief device
answer
opens to atmosphere and vents gas to atmosphere if preset pressure is exceeded
question
common fresh gas outlet functions to
answer
receive all the gases and vapors from the machine and delivers the mixture to the breathing system
question
function of breathing system
answer
-recieves gas mixture from machine -delivers gas to patient -removes co2 -maintains temperature and humidity of inspired mixture -allows continuous flow from machine to be converted into intermittent flow -allows for spontaneous, controlled or assisted respiratory
question
what other functions does the breathing system serve?
answer
1. gas sampling 2. monitors airway pressure, flow and volume
question
reservoir bag allows what?
answer
gas to accumulate during exhalation to prevent air dilution
question
reservoir bag provides a means whereby ventilation may be?
answer
controlled or assisted
question
reservoir bag can serve as a monitor of patient's spontaneous respiration because you can?
answer
see or feel the bag moving
question
_________ ______ protects patient from excessive pressure in breathing system
answer
reservoir bag
question
a ______ _______ is a large bore, corrugated tube
answer
breathing tube
question
breathing tubes provide a _____, _________ , _________ connection
answer
flexible, low-resistance, lightweight connection
question
corrugation functions to
answer
increase flexibility and help prevent kinking
question
_________ breathing tubes have no clear separation of inspired and expired gases
answer
mapleson
question
breathing tubes have no clear separation of inspired and expired gases means
answer
rebreathing will occur when the inspiratory flow exceeds fresh gas flow
question
composition of inspired mixture will depend on?
answer
how much re-breathing takes place
question
describe Mapleson A breathing tubes
answer
-fresh gas enters system near the reservoir bag -tubing connects the bag to the APL valve at the patient end
question
describe Mapleson B breathing tubes
answer
-fresh gas inlet and APL valve are both located near the patient port -reservoir bag is at the patient end of system
question
describe Mapleson C breathing tubes
answer
-identical to Mapleson B except that the corrugated tubing is omitted
question
describe Mapleson D breathing tubes
answer
-has T piece near patient -T piece is 3 way tubular connector with: patient connection port, fresh gas port, port for connection to corrugated tubing
question
BAIN modification
answer
fresh gas supply tube runs coaxially inside the corrugated tubing and ends at the point where the fresh gas would enter if the classic Mapleson D form was used
question
describe Mapleson E breathing tubes
answer
-T piece forms a reservoir -no ag
question
describe Mapleson F
answer
-has a bag with a mechanism for venting excess gases -a hole in tail or side of bag is occluded by a finger to provide a pressure
question
advantages of Mapleson F
answer
-equipment: simple, inexpensive and rugged (not many moving parts except APL valve) -variations in minimum volume affect ETCO2 less than circle system -in coaxial system (Bain) the inspiratory limb is heated by warm exhaled gas in the coaxial expiratory tubing -resistance is low -system is lightweight and not bulky -easy to position -compression and compliance volume losses are less than circle -fresh gas concentrations result in rapid changes in inspiratory gas composition -no Co2 absorbent
question
no co2 absorbent =
answer
no production of CO and compound A
question
disadvantages of Mapleson F
answer
-requires high gas flows -inspired heat and humidity tend to be low -optimum fresh gas flow is difficult to determine -in ABC, the APL valve is close to patient -E & F: difficult to scavenge -not suitable for patient's with MH
question
why is Mapleson F not suitable for patient's with MH?
answer
may not be possible to increase fresh gas flow to remove increased CO2
question
absorber assembly is usually attached to
answer
machine
question
absorber assembly consists of
answer
absorber, 2 ports for connection to breathing tubes and fresh gas inlet
question
other components of absorber assembly that may be mounted on the assembly
answer
-inspiratory and expiratory unidirectional valves -adjustable APL valve -bag mount -ventilator
question
canisters function to
answer
hold the absorbent
question
why are side walls of canisters transparent?
answer
so absorbent color can be monitored
question
how many canisters can you have?
answer
1 or 2
question
co2 absorption employs the general principle of?
answer
a base neutralizing an acid
question
types of absorbents
answer
1. high-alkali 2. low-alkali 3. alkali-free 4. lithium hydroxide
question
high-alkali absorbents contain?
answer
high amounts of K+/or Na hydroxide
question
example of high-alkali absorbent
answer
soda lime
question
low-alkali absorbents contain?
answer
less amounts of Na or K hydroxide
question
alkali-free absorbents consist of?
answer
Ca hydroxide with small amounts of other agents to accelerate Co2 absorption and bind water
question
lithium hydroxide reacts with co2 to form
answer
carbonate
question
limitations to lithium hydroxide
answer
-expensive -careful handling: burns eyes, skin and respiratory tract
question
indicators
answer
-an acid or base whose color depends on pH
question
indicators are added to absorbent to?
answer
signify when absorbents ability to absorb CO2 is exhausted
question
most common indicator
answer
ethyl violet
question
why is ethyl violet most common indicator?
answer
because color change is vivid
question
sevoflurane decomposes in the presence of ?
answer
some CO2 absorbents
question
compound A is a
answer
vinyl ether
question
compound A can have dose-dependent _______ effects
answer
nephrotoxic
question
factors influencing amount of compound A
answer
1. fresh gas flow 2. absorbent composition 3. absorbent temperature 4. sevo concentration 5. anesthetic length 6. water content
question
unidirectional valves ensure that gases flow
answer
toward the patient in one breathing tube and away int he other
question
inspiratory port
answer
downstream of inspiratory unidirectional valve through which gases pass toward the patient during inspiration
question
expiratory port
answer
upstream of unidirectional valve through which gases pass during exhalation
question
3 way tubular conncetor
answer
Y piece
question
2-22 mm ports for connection to?
answer
breathing tubes
question
1-15 mm port for connection to?
answer
ETT or LMA
question
user adjustable valve that releases gases to a scavenging system
answer
APL valve
question
APL valve is used to control?
answer
the pressure in the breathing system
question
APL valve can be spontaneous which means it..
answer
is fully opened no matter what ideal is set to
question
APL valve can be manual which means
answer
closes valve to ventilate patient
question
another name for pressure gauge
answer
manometer
question
pressure gauge/manometer is attached to
answer
exhalation pathway
question
newer machines have electronically displayed virtual _____
answer
pressure gauge
question
hanging bellows are on
answer
older machines
question
piston
answer
?
question
standing bellows
answer
?
