This document discusses different types of vaporizers used to deliver anesthetic gases to patients. It describes six classifications of vaporizers: 1) method of regulating output, 2) method of vaporization, 3) temperature compensation, 4) specificity, 5) resistance, and 6) location. Common vaporizers are then explained in more detail, including how they work, advantages, and disadvantages. Safety mechanisms are also reviewed to minimize risks from incorrect concentrations or agent delivery.

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

5. 5
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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