vaporizers

1. VAPORIZERS
Dr. ZIKRULLAH
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2. VAPORIZERS
Instrument designed to facilitate change of liquid
anaesthetic agent into its vapor and add a
controlled amount of this vapor to the flow of
gases going to the patient
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3. CLASSIFICATION OF
VAPORISERS
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I-METHOD OF REGULATING OUTPUT
a. variable bypass
b. measured flow
II-METHOD OF VAPORIZATION
a . flow over
b. bubble through
c . injection

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III-TEMPRATURE COMPENSATION
a . Thermo compensated
b . Non compensated
IV-SPECIFICITY
a . Agent specific
b . multi agent
V-RESISTANCE
a . Plenum
b . Draw over
VI-LOCATION
a . In circuit
b . Out of circuit

6. VARIABLE BYPASS
• Accept total gas flow from anaesthesia machine and deliver it
with a predictable concentration of vapor to common gas outlet
e.g. TEC vaporizer , ether bottle
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7. MEASURED FLOW
• Utilize a measured flow of carrier gas usually oxygen to pick up
anaesthetic vapor
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8. FLOW OVER VAPORIZER
• Carrier gas over surface of a liquid e.g
TEC vaporizer.
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9. BUBBLE THROUGH VAPORISER
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10. INJECTION VAPORIZER
• Known amount of agent is injected to deliver a desired
concentration of agent
e.g. TEC 6
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11. THERMO COMPENSATION
•To maintain a constant output
a . alteration in splitting ratio-bimetallic strip
b . computer control-electronic vaporizer
c . supplied heat-TEC 6
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13. RESISTANCE
•PLENUM
High resistance
eg-boyle’s , TEC
•DRAW OVER
Low resistance
eg- Goldman bottle , EMO
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14. LOCATION
IN SYSTEM-
patient’s inspiratory and expiratory gases go through the
vaporizer
OUT OF SYSTEM-
located out of breathing system and have a dedicated flow meter
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15. FACTORS AFFECTING VAPORIZER OUTPUT
• Flow through vaporizing chamber
• Surface area of liquid gas interface
• Temperature
• Time
• Gas flow rate
• Carrier gas composition
• Ambient temperature
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16. How much liquid agent does a vaporizer
use per hour?
• Ehrenwerth and Eisenkraft gives the formula
• 3 X Fresh gas flow(L/min) X Volume % = ml liquid used /hr
• This formula is based on the fact that typically 1 ml of liquid
volatile agent yields about 200ml of vapor

17. EFFECT OF LOW ATMOSPHERIC
PRESSURE
Concentration calibrated
-slight increase in vapor output
- concentration increase If expressed in volume percent
but deliver same amount of partial pressure
Measured flow
-delivered partial pressure and volume percent
increases
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18. EFFECT OF HIGH
ATMOSPHERIC PRESSURE
•Decrease output in both concentration
calibrated and measured flow
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19. EFFECT OF INTERMITTENT BACK
PRESSURE
•Transmission of positive pressure from
breathing system to machine and vaporizer
•Also seen with oxygen flush
• PUMPING EFFECT
• PRESURIZING EFFECT
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20. PUMPING EFFECT
•Increase in vaporizer output
•Especially seen when
-carrier gas flow is low
-agent in chamber is low
-dial setting is low
pressure fluctuations are high and
frequent
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23. MODIFICATIONS TO MINIMIZE PUMPING
EFECT
•Keep the vaporizing chamber small or
increase the size of bypass chamber
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•Add spiral or large diameter tube to lead
into vaporizing chamber

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•Increase resistance to gas flow

26. Check valve to
prevent backward
flow of gas
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27. PRESSURIZING EFFECT
•Seen when
-high flow
-large pressure fluctuations
-low dial setting
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29. HAZARDS
I. Incorrect agent
II . Tipping
-high concentration of vapor delivered
III . Overfilling
-high concentration delivered
-decrease in surface area for vaporization
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IV . Incorrect concentration delivered
V . Reversal of flow
VI . Leaks
-wastage
-wrong concentration
OT pollution

31. SAFETY MECHANISM
• AGENT SPECIFIC FILLING SYSTEM
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• Cap of bottle removed
• Adapter screwed to bottle

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•Low filling port-minimize overfilling
•Secured vaporizers-minimize tipping
•Interlock prevent administration of more than
one agent at a time -SELECTATEC system

36. ORDER OF VAPORIZERS
• Upstream-low vapor pressure , less potent
• Downstream-high vapor pressure , more potent , explosive
, easy to clean
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37. DIFFERENT TYPE OF
VAPORIZERS
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OPEN DROP MASK

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40. BOYLES BOTTLE
•Concentration calibrated
•Flow over or bubble through
•Non temperature compensated
•Multiple agent
•Out of circuit vaporizer
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41. OXFORD MINIATURE VAPORISER
•Variable bypass
•Flow over
• temperature compensated
•Multiple agent
•Out of circuit
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42. -Concentration
calibrated
-flow over
-temp compensated
-draw over
-in circuit
EPSTEIN
MACINTOSH
OXFORD (EMO)
VAPORISER
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43. GOLDMAN VAPORIZER
• Concentration calibrated
• Flow over
• Temp compensated
• Multi agent
• Draw over
• In circuit
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44. TEC VAPORIZER (I-V)
•Variable by pass
•Concentration calibrated
•Flow over with wick
•Out of circuit
•Temperature compensated
•Agent specific
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45. TEC -6 VAPORIZER
•For Desflurane
•Concentration calibrated
•Thermo compensated
•Agent specific
•Out of circuit
•Plenum
•Gas vapor blender
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47. WHY DESFLURANE HAS A SEPARATE
VAPORIZER
•Its vapor pressure is higher than other agents
•Desflurane boils at 22.8 degree Celsius
•MAC is higher than that of other modern
volatile anaesthetics
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49. TEC 7 VAPORISER
•Similar to TEC 5
•Easy fill mechanism
•Non spill
•Prismatic sight glass
•Smaller graduation for accuracy
•Accurate through clinical flow range
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51. ALADIN CASSETTE
•Concentration calibrated
• flow over
•Automatic thermo compensation
•2 parts
#cassette-agent specific magnetic code
# anaesthesia delivery unit-contain software
to recognize agent , part of workstation
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53. VAPOR 2000/3000
•Concentration calibrated
•Flow over
•Automatic temperature calibration
•Variable bypass
•Agent specific
•Out of circuit
•Vapor 3000 is only for Isoflurane & Sevoflurane
and 2000 is also for Halothane & Enflurane
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55. SIEMENS KION
•Concentration calibrated injector
•No thermal compensation
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56. THANK YOU
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