Anesthesia Machine

1
Anesthesia Machine

• Presented by Gil Soto C.R.N.A

2
Danger

• Unpleasant Surprises

3
Lecture Outline

• The Machine
• Gas Supply Systems Hospital
  pipeline Cylinder
• High Pressure System (exposed to cylinder
  pressure)
• Intermediate Pressure System (exposed to pipeline
  press)
• Low Pressure System (distal to flowmeter needle
  valve)
• Circle System CO2 Absorber System
  Unidirectional Valves
• Ventilator
• Scavenger System

4
Anesthesia Machine Checkout

• General
• Anesthesia Apparatus Checkout Recommendations,
  1993 (Taken from the FDA)
• This checkout, or a reasonable equivalent, should
  be conducted before administration of anesthesia.
  These recommendations are only valid for an
  anesthesia system that conforms to current and
  relevant standards and includes an ascending
  bellows ventilator and at least the following
  monitors capnograph, pulse oximeter, oxygen
  analyzer, respiratory volume monitor (spirometer)
  and breathing system pressure monitor with high
  and low pressure alarms. This is a guideline
  which users are encouraged to modify to
  accommodate differences in equipment design and
  variations in local clinical practice. Such local
  modifications should have appropriate peer
  review. Users should refer to the operator's
  manual for the manufacturer's specific procedures
  and precautions, especially the manufacturer's
  low pressure leak test (step 5).
• If an anesthesia provider uses the same machine
  in successive cases, these steps need not be
  repeated or may be abbreviated after the initial
  checkout.

5
Anesthesia Machine Checkout

• Steps 1-3
• Emergency Ventilation Equipment 1.  Verify
  Backup Ventilation Equipment is Available
  Functioning
• High Pressure System 2.  Check Oxygen Cylinder
  Supply  a.  Open 02 cylinder and verify at least
  half full (about 1000 psi).  b.  Close cylinder.
  3.  Check Central Pipeline Supplies  a.  Check
  that hoses are connected and pipeline gauges read
  about 50 psi.

6
Anesthesia Machine Checkout

• Steps 4-7
• Low Pressure Systems 4.  Check Initial Status
  of Low Pressure System  a.  Close flow control
  valves and turn vaporizers off.  b.  Check fill
  level and tighten vaporizers' filler caps. 5. 
  Perform Leak Check of Machine Low Pressure System
   a.  Verify that the machine master switch and
  flow control valves are OFF.  b.  Attach
  "Suction Bulb" to common Fresh gas outlet.  c. 
  Squeeze bulb repeatedly until fully collapsed.
   d.  Verify bulb stays fully collapsed for at
  least 10 seconds.  e.  Open one vaporizer at a
  time and repeat 'c' and 'd' as above.  f. 
  Remove suction bulb, and reconnect fresh gas
  hose. 6.  Turn On Machine Master Switch and all
  other necessary electrical equipment. 7.  Test
  Flowmeters  a.  Adjust flow of all gases through
  their full range, checking for smooth operation
  of floats and undamaged flowtubes.  b.  Attempt
  to create a hypoxic 02/N20 mixture and verify
  correct changes in flow and/or alarm.

7
Anesthesia Machine Checkout

• Scavenging System 8.  Adjust and Check
  Scavenging System  a.  Ensure proper connections
  between the scavenging system and both APL
  (pop-off) valve and ventilator relief valve.
   b.  Adjust waste gas vacuum (if possible).
   c.  Fully open APL valve and occlude Y-piece.
   d.  With minimum 02 flow, allow scavenger
  reservoir bag to collapse completely and verify
  that absorber pressure gauge reads about  zero.
   e.  With the 02 flush activated allow the
  scavenger reservoir bag to distend fully, and
  then verify that absorber pressure gauge reads 
  lt10 cm H20.

8
Anesthesia Machine Checkout

• Breathing System 9.  Calibrate 02 Monitor  a. 
  Ensure monitor reads 21 in room air.  b. 
  Verify low 02 alarm is enabled and functioning.
   c.  Reinstall sensor in circuit and flush
  breathing system with 02.  d.  Verify that
  monitor now reads greater than 90. 10.  Check
  Initial Status of Breathing System   a.  Set
  selector switch to "Bag" mode.   b.  Check that
  breathing circuit is complete, undamaged and
  unobstructed.   c.  Verify that C02 absorbent is
  adequate.   d.  Install breathing circuit
  accessory equipment (e.g. humidifier, PEEP valve)
  to be used during the case. 11.  Perform Leak
  Check of the Breathing System   a.  Set all gas
  flows to zero (or minimum).   b.  Close APL
  (pop-off) valve and occlude Y-piece.   c. 
  Pressurize breathing system to about 30 cm H20
  with 02 flush.   d.  Ensure that pressure
  remains fixed for at least 10 seconds.   e. 
  Open APL (Pop-off) valve and ensure that pressure
  decreases.

9
Anesthesia Machine Checkout

• Manual and Automatic Ventilation Systems 12. 
  Test Ventilation Systems and Unidirectional
  Valves   a.  Place a second breathing bag on
  Y-piece.   b.  Set appropriate ventilator
  parameters for next patient.   c.  Switch to
  automatic ventilation (Ventilator) mode.   d. 
  Fill bellows and breathing bag with 02 flush and
  then turn ventilator ON.   e.  Set 02 flow to
  minimum, other gas flows to zero.   f.  Verify
  that during inspiration bellows delivers
  appropriate tidal volume and that during
  expiration bellows fills completely.   g.  Set
  fresh gas flow to about 5 L/min.   h.  Verify
  that the ventilator bellows and simulated lungs
  fill and empty appropriately without sustained
  pressure at end expiration.   i.  Check for
  proper action of unidirectional valves.   j. 
  Exercise breathing circuit accessories to ensure
  proper function.   k.  Turn ventilator OFF and
  switch to manual ventilation (Bag/APL) mode.  
  l.  Ventilate manually and assure inflation and
  deflation of artificial lungs and appropriate
  feel of system resistance and compliance.   m. 
  Remove second breathing bag from Y-piece.

10
Anesthesia Machine Checkout

• Monitors 13.  Check, Calibrate and/or Set Alarm
  Limits of all Monitors Capnometer, Pulse
  Oximeter, Oxygen Analyzer, Respiratory Volume
  Monitor (Spirometer), Pressure Monitor with High
  and Low Airway Alarms
• Final Position 14.  Check Final Status of
  Machine   a.  Vaporizers off   b.  AFL valve
  open   c.  Selector switch to "Bag"   d.  All
  flowmeters to zero   e.  Patient suction level
  adequate   f.  Breathing system ready to use

11
The Anesthesia Machine

• The anesthesia gas machine is a device which
  delivers a precisely-known but variable gas
  mixture, including anesthetizing and
  life-sustaining gases.

12
The MachineOhmeda N.A.Drager (Narkomed)
13
Anesthesia Machine Jackson Memorial Hospital
14
Manufacturers Names

• North American Dräger (Telford, PA) is the
  manufacturer of the Narkomed 2C, Narkomed 4,
  Narkomed GS, Narkomed 6000, Narkomed Julian,
  Narkomed MRI and Narkomed Mobile models.
• Datex-Ohmeda (Madison WI) manufactures the AS/3
  ADU, Aestiva, Modulus SE, Excel 210, and Excel
  110

15
Some Numbers to Remember

• The hospital pipeline is the primary gas source
  at 50 psi (normal working pressure of most
  machines).
• Cylinders O2 is supplied at around 2000 psi
  (regulated to approximately 45 psi after it
  enters the machine).
• Oxygen flush is a "straight shot" from supply to
  delivery point, 35-75 L/min.
• OSHA Fact Sheet (1991) on Waste Anesthetic Gases
  (WAGs) occupational exposure should be limited to
  an eight hour time-weighted average of not more
  than 2 ppm halogenated agents (Halothane,
  Enflurane, Isoflurane, Sevoflurane, Desflurane)
• If Halogenated agent is used in combination with
  nitrous oxide, then ONLY 0.5 ppm OF THE
  HALOGENATED AGENT IS ALLOWED
• No more than 25 ppm nitrous oxide can be used at
  all times (with or without Halogenated Agent)

16
Minimal Components

• O2 Pipeline N2O Pipeline
• 
  
• O2 Flowmeter N2O Flowmeter
• Container with VAA
• Bag-valve-mask device
• Patient

17
Straight-line model SPDD (Supply/Processing/Deliv
ery/Disposal)
18
Oxygen has five "tasks

• It powers the ventilator driving gas
• O2 flush
• Activation of low pressure alarms
• Activation of fail-safe mechanisms (O2
  pressure sensor shut-off )
• Proceeding through the flowmeter

19
Other gases One task Only

• Transported via flowmeter breathing circuit to
• Anesthetize pt (N2O)
• Sustain Life (Air)

20
(No Transcript)
21
Basic Schematics
22
Gas Supply SystemsHospital Pipeline
23
DISS

• Pipeline inlets are connected with DISS (diameter
  index safety system) non-interchangeable
  connections.
• The check valve, located down stream from the
  pipeline inlet, prevents reverse flow of gases
  (from machine to pipeline, or to atmosphere),
  which allows use of the gas machine when pipeline
  gas sources are unavailable.

24
PISS
PISS (pin-index safety system) prevents
misconnection of a cylinder to the wrong yoke.
Keep cylinders closed except when checking
machine, or while in use (if O2 from pipeline is
unavailable)
25
(No Transcript)
26
Gas Supply SystemsCylinder
Pin Index Safety System
O2 2,5
N2O 3,5
27
High Pressure System(parts which receive gas at
cylinder pressure)

• hanger yoke (including filter and unidirectional
  valve)
• yoke block (with check valves)
• cylinder pressure gauge
• cylinder pressure regulators

28
Bourdon Gauge
29
Hanger Yoke Check Valve

• Hanger Yoke
• orients cylinders
• provides unidirectional flow
• ensures gas-tight seal.

• Check Valve
• minimize trans-filling
• allows change of cylinders during use
• minimize leaks to atmosphere if a yoke is empty.

30
Check Valve
31
(No Transcript)
32
More on Cylinders

• The cylinder pressure regulator converts high,
  variable cylinder pressure to a constant pressure
  of approximately 45 psi downstream of the
  regulator.
• This is intentionally slightly less than pipeline
  pressure, to prevent silent depletion of cylinder
  contents if a cylinder is inadvertently left open
  after checking its pressure.
• Cylinder pressure gauge indicates pressure in the
  higher-pressure cylinder only (if two are opened
  simultaneously).

33
E cylinder Characteristics

• Gas US (International) PSI
  Capacity (L) PISS
• O2 Green (white)
  1900 660 2-5
• N2O Blue (blue) 745
  1590 3-5
• Air Yellow (B W)
  1900 625 1-5
• Well use 2000psi for O2 instead of
  1900psi

34
Intermediate Pressure System
Hospital Pipeline Outlets
Machine piping guts
Hospital Pipeline Inlets
Gauges-pipeline (intermediate press. )
35
Intermediate Pressure System

• (receives gases at low, relatively constant
  pressures (37-55 psi, pipeline pressure)
• (For consistency well use 50 psi)
• pipeline inlets and pressure gauges
• ventilator power inlet
• Oxygen pressure-failure device (fail-safe) and
  alarm
• flowmeter valves
• oxygen second-stage regulator
• oxygen flush valve

36
Oxygen pressure-failure device (fail-safe) and
alarm

• What happens if you lose oxygen pipeline
  pressure?
• The fail safe device ensures that "Whenever
  oxygen pressure is reduced and until flow ceases,
  the set oxygen concentration shall not decrease
  at the common gas outlet" (from ASTM F1161).
• The loss of oxygen pressure results in alarms,
  audible and visible, at 30 psi pipeline pressure.
  
• Fail-safe systems don't prevent hypoxic mixtures.
  

37
Fail-safe systems don't prevent hypoxic mixtures

• as long as there is pressure in the O2 line,
  nothing in the fail safe system prevents you from
  turning on a gas mixture of 100 nitrous oxide
  (however, this should be prevented by the hypoxic
  guard system)
• or 100 helium (which wouldnt be prevented by
  the hypoxic guard).
• Datex-Ohmeda terms their fail safe a "pressure
  sensor shut off valve"- at 20 psi oxygen, the
  flow of all other gases are shut off. Dräger's,
  "oxygen failure protection device" (OFPD)
  threshold is proportional, unlike Ohmeda's which
  is off-or-on.

38
Fail-safe systems don't prevent hypoxic mixtures
(Cont)

• Ohmeda uses a second-stage O2 pressure regulator
  (ensures constant oxygen flowmeter input until
  supply pressure is less than 12-16 psi). The
  oxygen ratio monitor controller (ORM newer or
  ORMC, both by Dräger) shuts off nitrous oxide
  when oxygen pressure is less than 10 psi

39
Pipeline Trouble

• Pipeline sources are not trouble free
  contamination (particles, bacteria, viral,
  moisture), inadequate pressure, excessive
  pressures, and accidental crossover (switch
  between oxygen and some other gas such as nitrous
  oxide or nitrogen) are all reported.

40
What if you lose oxygen pipeline pressure?

• Open the emergency oxygen cylinder fully (not
  just the three or four turns used for checking)
• Disconnect the pipeline connection at the wall
• Why? Something is wrong with the oxygen pipeline.
  
• What if the supply problem evolves into a
  non-oxygen gas in the oxygen pipeline? If so, it
  will flow to the patient (pipeline pressure 50
  psi) rather than your oxygen cylinder source
  (down-regulated to 45 psi).
• If you are lucky, the oxygen alarm will sound to
  warn you of the change (you do set your alarms,
  don't you?).
• If for some reason the oxygen analyzer does not
  warn of the crossover, the pulse oximeter will-
  but only after the oxygen has been washed out by
  ventilation from the patient's functional
  residual capacity and vessel-rich group.

41
Reinforcement!!!!

• Disconnect the pipeline connection at the wall if
  oxygen pipeline pressure is lost. It's also
  easier to remember one strategy which works for
  any problem with the pipeline, rather than to
  remember that sometimes you must, and sometimes
  it is optional, to disconnect. And use that
  oxygen analyzer always!
• Ventilate by hand rather than with the mechanical
  ventilator (which uses cylinder oxygen for the
  driving gas if the pipeline is unavailable)

42
HOW LONG BEFORE O2 TANK IS EXHAUSTED???

• -The time to exhaustion is calculated by
  dividing the remaining O2 volume in the cylinder
  by the rate of consumption of O2.
• -Remaining volume in liters (L) in an E-cylinder
  is calculated by dividing the cylinder pressure
  in psig by 2000 psig and multiplying by 660 L.

43
EXAMPLE

• If cylinder gauge reads 1,000 psig, this
  represents (1000/2000) X 660 330 L left in that
  tank. The rate of consumption of O2 during
  mechanical ventilation is the sum of the O2 flow
  meter setting and the patients minute
  ventilation (VT in L x RR in breaths/min).
• If FGF is 0.5 L/min O2 and 1.0 L/min N2O and VT
  is 0.7 L and RR is 10 bpm, then the minute
  ventilation is
• 7 L/min (0.7L x 10 bpm)
• The total O2 consumption is 7.5 L/min. The
  expected time to exhaustion is thus approximately
  330 L divided by 7.5 L/min 44 min (ignoring the
  gas sampled by the gas analyzer and leaks)

44
The Low-pressure system(distal to flowmeter
needle valve)

• flowmeter tubes
• vaporizers
• check valves (if present)
• common gas outlet

45
Flowmeters
-Thorpe tube is an older term for flowmeters.
-Components needle valve, indicator float,
knobs, valve stops. -Flow increases when the
knob is turned counterclockwise (same as
vaporizers). -At low flows, the annular-shaped
orifice around the float is (relatively) tubular
so (according to Poiseuille's Law) flow is
governed by viscosity. (laminar flow) -At high
flows (indicated on the wider top part of the
float tube), the annular opening is more like an
orifice, and density governs flows. (turbulent
flow)
46
Low Pressure System

• Distal to Flowmeter Needdle Valve
• Flow Meters- measures and indicates the
  rate of gas flowing through it. Variable
  orifice/Thorpe tube-constant press. flow meters.
  Rate of
  flow r/t 1) pressure drop across the
  constriction 2) size of annular
  opening
  
  3)
  Physical properties of the gas
  (viscosity and
  density) Indicator,
  float or bobbin- 1) rotometers
  2) non-rotating floats
  3) ball floats Sequence of
  flowmeters tubes is very important to
  decrease chance of hypoxic mixture.,
  Gas flow is from left to right, O2 on
  right side. Any leak in flowmeters will
  vent other gas out or
• entrain air
  before O2 is added to gas mixture decreasing
  
  chance that O2
  will be lost or diluted.

FLOW
47
More on Flowmeters

• Needle valve can be damaged if it is closed with
  force
• Flowtube (Thorpe tube) is tapered (narrower at
  bottom) and gas-specific
• If gas has 2 tubes, they are connected in series
  with a single control valve

48
Did anyone say Flowmeters??

• Care of flowmeters includes ensuring that
• floats spin freely
• qualified service personnel regularly maintain
  gas machines
• an O2 analyzer used always (of course, the
  readings are erroneous during use of nasal
  cannula)
• one never adjusts a flowmeter without looking at
  it
• one includes flowmeters in visual monitoring
  sweeps
• one turns flowmeters off before opening
  cylinders, connecting pipelines, or turning
  machine "on".

49
Low Pressure System

• Safety Devices-Purpose is to decrease risk of
  hypoxic mixture Mandatory Minimum O2 Flow-
  factory preset minimum O2 flow that always flows
  when machine is on. Minimum O2/N2O Ratio
  13 Device or proportioning system Flow
  valves linked mechanically or pneumatically so O2
  cannot be set below 25. Alarm will signal if
  O2/NO2 ratio falls below preset value
• O2/NO2 Proportioning Device-Automatically
  mixes O2 and NO2 to setting selected on dial

50
(No Transcript)
51
(No Transcript)
52
(No Transcript)
53
Hypoxic breathing is POSSIBLE

• hypoxic guard systems CAN permit hypoxic
  breathing mixtures IF
• wrong supply gas in oxygen pipeline or cylinder,
• defective pneumatic or mechanical components,
• leaks exist downstream of flow control valves, or
  
• if third inert gas (such as helium) is used.

54
Low Pressure System

• Vaporizers- Classification A. Method of
  regulating output concentration 1.
  Concentration calibrated 2. Measured
  flow B. Method of vaporization 1.
  Flow over 2. Bubble Through
  3. Injection C. Temperature compensation
  1. Thermocompensation 2.
  Supplied heat D. Specificity 1.
  Agent specific 2. Multiple agent
  E. Resistance 1. Plenum
  2. Low resistance

55
VAPORIZERS

• Vapor Pressure (VP) Molecules escape from a
  volatile liquid to the vapor phase, creating a
  saturated vapor pressure at equilibrium
• VP is independent of Atmospheric Press
• VP increases with Temperature
• VP depends ONLY on the Physical Characteristics
  of the Liquid on its Temperature

56
CLASSIFICATION

• Variable bypass
• Fresh gas flow from the flowmeters enters the
  inlet of any vaporizer which is on. The
  concentration control dial setting splits this
  stream into bypass gas (which does not enter the
  vaporizing chamber), and carrier gas (also called
  chamber flow, which flows over the liquid agent)

57
CLASSIFICATION

• Flow over
• Carrier gas flows over the surface of the liquid
  volatile agent in the vaporizing chamber (as
  opposed to bubbling up through it (as in the
  copper kettle and Vernitrol)

58
CLASSIFICATION

• Temperature compensated
• Equipped with automatic devices that ensure
  steady vaporizer output over a wide range of
  ambient temperatures
• Agent-specific
• Only calibrated for a single gas, usually with
  keyed fillers that decrease the likelihood of
  filling the vaporizer with the wrong agent
• Out of circuit
• As opposed to (much) older models such as the
  Ohio 8 (Boyle's bottle) which were inserted
  within the circle system.

59
Vaporizer Interlock Mechanism
Safety mechanism that allows ONLY one vaporizer
at a time to be opened
60
Circle System
Circle System- CO2 absorber housing and absorber,
unidirectional valves, inspiratory and expiratory
ports, fresh gas inlet, APL valve, pressure
gauge, breathing tubes, Y-piece, reservoir bag,
bag/vent switch selector, respiratory gas monitor
sensor.
61
Circle System

• CO2 Absorber System Housing (canister support),
  Absorbent, baffles, side tube
• Unidirectional Valves-aka Flutter valves, one way
  valves, check valves, directional valves, dome
  valves
• Canister-Air space 50, void space 42, pore
  space 8
• Soda Lime 4 Sodium Hydroxide, 1 potassium
  hydroxide, 14-19 H2O, and calcium hydroxide to
  make 100, Silica and kielselguhr for
  hardness
  Indicator for color change with exhaustion of
  CO2 absorption capabilities CO2H2O?H2CO3 2
  NaOH2H2CO3Ca(OH)2 ?CaCO3NaCO34H2O heat
  released 13,700 cal./mole CO2 absorbed
• Barium Hydroxide Lime 20 Barium hydroxide, 80
  calcium hydroxide, and /-
  potassium hydroxide, Indicator for color
  change with exhaustion of CO2 absorption
  capabilities Ba(OH)2 . 8H2OCO2?BaCO39H2O 9H
  2O9CO2 ?9H2CO3 9H2CO39Ca(OH) 2 ?
  9CaCO318H2O 2KOHH2CO3 ? K2CO32H2O Ca(OH
  )2K2CO3 ? CaCO32KOH Regeneration (color
  change loss) with rest can occur. Appears new but
  is exhausted Granule size 4-8 mesh- 4 mesh equals
  strainer with 4 openings/inch

62
Circle system CO2 Absorber System
Removing canister soda lime
canisters unlocked
canister locking lever
Removing both canisters soda lime
Replacing fresh soda lime
Exhausted soda lime
63
Circle system Unidirectional Valves

• Unidirectional valves-aka flutter valves, one way
  valves, check valves, directional valves, dome
  valves. Found on Inspiratory and Expiratory
  flow ports

Narkomed Machine
Ohmeda Machine
64
Ventilator

• Ventilator Components Driving gas supply,
  injector, controls, alarms, safety-release valve,
  bellows assembly, exhaust valve, spill valve,
  connection for ventilator hose

Bellows assembly
Ventilator controls
65
Ventilator

• Driving gas supply or power gas supply-O2
  pneumatically drives (compresses) ventilator
  bellows
• Injector or Venturi mechanism-Increases the flow
  of driving gas by using the BERNOULLI Principle-
  As a gas flow meets a restriction, its lateral
  pressure drops. Any opening in the tube at this
  constriction will entrain air (suck air in)
• Controls-Adjusts Flow, Volume, Timing, and
  Pressure of the driving gas that compresses the
  bellows Pneumatic-Uses pressure changes to
  initiate changes in respiratory cycle Fluidic or
  fluid logic-Uses gas streams through channels in
  solid material. Allow for compact
  ventilator Electronic-Electronic control of
  many addition ventilation parameters powered by
  a driving gas on newer machines. Must have both
  power and pnuematics.
• Alarms-ASTM standards group alarms into three
  levels High, Medium, Low Priority correlates
  tooperator immediate action, prompt action,or
  awareness. Loss of main power is the only
  required alarm with a required duration of at
  least 2 minutes
• Safety relief valve-aka pressure limiting valve,
  drving gas pressure relief valve. Vents driving
  gas if factory pre-set pressure is reached (65-80
  cm H2O) or adjustable set pressure is reached.

66
Bernoullis Principle

• At constriction
• Flow is higher
• Pressure is lower

67
Ventilator

• Bellows Assembly Housing- Usually made of
  hard rigid clear plastic Bellows
  ASCENDING-standing, upright. Compressed downward
  during inspiration. ASCEND DURING EXPIRATION
• Pressure is always positive. PEEP 2-4 cm
  H2O. DESCENDING-hanging, inverted. Compressed
  upward during inspiration. DESCEND DURING
  EXPIRATION. Weight of bellows results in negative
  airway pressure during exhalation until bellow
  refilled.
• 
  IMPORTANT difference between ascending and
  descending is that when there is a major leak
  or disconnect, the ascending bellows will
  collapse (unless prevented by scavenging system).
  When a disconnection occurs with a descending
  bellows system, the ventilator will continue
  its upward movement and downward movements,
  drawing in room air and driving gas during its
  descent and discharging it during the upward
  movement. Gas flow during upward movement may
  generate enough pressure such that the low
  pressure alarm is not activated.

What type is shown?
Remember that the type is described by how the
bellows move during EXPIRATION
68
Scavenger System

• Scavenger System consists of 1) gas collecting
  assembly, 2) a transfer means, 3) the interface,
  4) gas disposal tubing, 5) gas disposal assembly.
  (some or all components may be combined). AS
  TM standard fitting size for scavenger hoses 19
  mm ( international standard 30mm) to prevent
  incorrect connection to breathing hoses (22mm).

3
2
1
45
45
1
69
REFERENCES

• NZ pg 247-252
• MM pg 35-49
• DD pg 3-74
• http//chico.med.yale.edu/machine/agmpart1.htmGen
  eral20features
• http//www.anest.ufl.edu/eduweb/vam/

70
Unknown
The essence of intelligence is skill in
extracting meaning from
everyday experience
71
Anesthesia Machine

• What is the PISS numbers for O2, for N2O?
• What is the line pressure for O2 for N2O?
• What is the tank pressure for O2 for N2O?

72
Anesthesia Machine

• The O2 pressure alarm goes off, you should
• It is not possible to deliver a hypoxic mixture.