Anesthesia Machine Flashcards
what AANA - Standards for Nurse Anesthesia Practice is used?
standard VIII (8)
gas supplies connected to the machine
High pressure system
blending of gases and volatile agent based on control settings; regulated down to a level to deliver to patients
Low pressure system
fresh gas mixture passes from machine to patient
Breathing system
collects and disposes of excess gases; contaminated air
Scavenging system
what is the “back-up system”
e cylinder
what do check-valves do?
ensure no retrograde flow, prevent leakage
what colors are the pipe lines?
oxygen=green
air=yellow
nitrous=blue
what is the pressure gauge for hospital pipeline?
50 to 55 psig
what utilizes the diameter of the connection is different between the 3 on both ends (so that you cant take the nitrous hose to connect into the oxygen inlet, etc.)
DISS (diameter indexed safety system)
what is the pressure gauge for cylinder gas inlet?
45 psig
what can high pressure cause in patient?
barotrauma (pneumo)
how full should the cylinder be?
at least 1000! (greater than half full, 1900)
if less than that, change out the cylinder
position of OXYGEN pins?
2-5 (think “25” is the ideal age)
position of NITROUS pins?
3-5 (think “35” is starting to get a little old and loopy)
position of AIR pins?
1-5 (think “15” is the age when your brain is full of air)
how do you allow gauge to read 0?
bleed it
if 0 is not the baseline, gauge will only read accurately pressures that are higher than the baseline
(think like zeroing a scale before using it)
how do the bellows move down?
oxygen “powering”; compressing them down
do you hit the o2 flush valve button when patient is on ventilator?
NO
this would cause barotrauma during the inspiratory phase (35 to 75L/min of o2)
low o2 supply pressure alarm alarms within how many seconds?*
Reservoir-reed device is used within 5 seconds; if it drops below 30 psig
o2 pressure failure safety mechanism (fail-safe) occurs if o2 pressure falls below what?*
25 psig
shuts off the nitrous so patient does not become hypoxic
the machine just looks at the pressure, not looking at the type of gas!*
which type of gas should be closet to the vaporizers? downstream? on the right?
oxygen
To minimize risk of hypoxic mixture being delivered if leak occurs in the flowmeters
what is coated with conductive subtance to minimize static electricity?
flow/thorpe tubes
tapered
higher the flow, the more turbulent probably
where do you read the number for a tapered float?
at the very top
where do you read the number for a sphere float?
center
how big is a small thorpe tube?
1 liter
Should you turn your flows off before you turn machine off?
YES
to prevent damaging the float stop
4 things associated with the Touch-Index O2 flow control knob
1) fluted
2) size difference
3) protrudes further
4) most right
chain that connects oxygen flow meter to nitrous flow meter?
Link-25
what does the proportioning system help deliver oxygen at?
at least 25% + 4% O2
what are basal metabolic needs for oxygen? minimal oxygen flow when machine is on for the flow meter?
150ml/min
where gases from different flowmeters mix together and have opportunity to enter into a vaporizer which is attached here?
Manifold
what prevents using more than one vaporizer at a time
Interlock-exclusion system
what are 3 places leaks could occur in low pressure system?
flow reader
vaporizer
manifolds
Compress bulb, then plug into machine, make sure it stays compressed (so that there is no leak) ?
common/fresh gas outlet
how long should bulb be compressed?
10 seconds
what 3 places does electricity flow from the system switch?
ventilator
monitors
desflurane vaporizer (to heat it up)
what does turning off the electricty do?
it releases the pressure to atmosphere and lets the valves rest
what does NOT rely on electrical power?
spontaneous or manually assisted ventilation
mechanical flowmeters
scavenging
laryngoscope, flashlights
intravenous bolus or infusion
battery operated peripheral nerve stimulators or intravenous infusion pumps
monitoring using the anesthetist’s five senses
**typically fresh gas flow, vaporizers, and manual ventilation function (know specifics in operator’s manual) are maintained
what color does co2 absorber turn when old?
purple due to the acid
if APL valve was all the way closed, what would we generate?
70 cmh20 (CHECK this number!)
Safety features of the breathing system
Antidisconnect fresh gas hose connector
Antidisconnect pressure sampling line connection
Ventilator low airway pressure alarm
Ventilator pressure-limiting adjustment knob
Ventilator pressure relief valve
which is preferred, active or passive scavenging system?
active
passive is used in medical missions with evacuation hose
what allows the waste gases which enter the system in uneven delivery to be handled in a constant, continuous manner?
reservoir (gray bag)
what is from APL valve and ventilator pressure relief valve
collecting hoses
adjust the amount of vacuum from the hospital disposal influencing the scavenging system
vacuum control (active system)
if vacuum in scavenging system is not high enough, pressure will NOT back up into breathing system
(should be <10*)
Positive pressure relief mechanism
if vacuum is too strong, the gases to be delivered to the patient will NOT be affected
(should be >0*)
Negative pressure relief mechanism
Scavenging system: gas enters the scavenging system when the peak pressure exceeds the opening pressure of the APL valve
Manual ventilation
Scavenging system: during late exhalation and the expiratory pause after the ventilator bellows have returned to full position
Mechanical ventilation
Scavenging system: during late exhalation and the expiratory pause after the reservoir bag is full
Spontaneous ventilation
5 functions/paths of Oxygen?**
1) Go to oxygen flowmeter
2) Go to O2 flush
3) Activate oxygen pressure failure safety mechanism (fail-safe)
4) Activate oxygen low-pressure alarm
5) Powers the mechanical ventilator bellows
does the o2 flush skip the vaporizers?
YES, goes straight to the common gas outlet
does the o2 driving bellows skip the vaporizers?
YES, goes straight to the breathing circuit
is an oxygen analyzer essential?
YES
Irreversible hypoxic brain injury after 4 minutes of arterial desaturation!
3 Primary purposes of the machine?
1) provide oxygen
2) blend anesthetic gas mixture
3) To allow ventilation of patient’s lungs, whether spontaneous, assisted, or controlled
what is patient ready mode?
APL open
bag/vent switch in bag mode
all flows off
mask in place
vaporizers off
decreases O2 pressure to 16-20 psig ( N2O reduced to 32 psig)***
Second-stage regulator
connected to the mechanical ventilator and O2 flush valve
o2 power outlet
what is an example of the proportioning system
link-25
what is the ratio for the proportioning system
Ratio of N2O to O2 is not more than 3:1
what is the purpose of the proportioning system**
to not allow a hypoxic mixture (o2 of less than 21%***)
add vaporized anesthetic agent to gas flow
Calibrated Vaporizers
interfaces between the machine and the disposal system
manifold of the scavenging system
what does the second stage regulator decrease N20 down to
32 psig
what does the second stage regulator decrease O2 down to
16-20 psig
KNOW FOR EXAM
if vacuum of SCAVENGING system is not high enough, pressure will not back up into breathing system (should be <10*)
- APL OPEN
- Bag mode
- Y piece occluded
- Hit O2 button
POSITIVE pressure relief mechanism (scavenging)
KNOW FOR EXAM
if vacuum of SCAVENGING system is too strong, the gases to be delivered to the patient will not be affected (should be >0*)
NEGATIVE pressure relief mechanism (scavenging)
* APL OPEN
* Bag mode
* Y piece occluded
KNOW FOR EXAM
Machine should be off, compress bulb then plug it in, it should stay compressed for 10 seconds
Turn on each vaporizer, repeat step
LOW-Pressure Circuit Leak Test
KNOW FOR EXAM
- Occlude Y-piece
- All flows off
- APL valve CLOSED
- Bag mode
- Hit O2 flush up to 30
Ensure 30 on gauge holds for 10 seconds, release pressure with APL valve
POSITIVE Pressure Leak Test
Delivers gas from CGO to patient
breathing system
pipeline and cylinder
high pressure system
flowmeters and vaporizers
low pressure system
