This document discusses vaporizers, which are instruments used to facilitate the vaporization of liquid inhalational anesthetic agents for controlled delivery during anesthesia. It covers the basic physics of vaporization, classifications of vaporizers, examples of older vaporizer models, and features of newer electronic vaporizers. Specifically, it describes the TEC-6 desflurane vaporizer, which is an electrically heated, dual circuit gas/vapor blender that maintains a constant temperature for precise desflurane delivery. Safety features of modern vaporizers are also outlined.

1. BY
DR. S. PADMANABHA
PROF. & H.O.D.,
DEPT. OF ANAESTHESIOLOGY,
YENEPOYA MEDICAL COLLEGE
MANGALORE – 575 018.
VAPORIZERS

2. VAPORIZERS
• INTRODUCTION
• BASIC PHYSICS
• CLASSIFICATIONS
• OLD VAPORIZERS
• NEWER VAPORIZERS

3. INTRODUCTION
• Both inhalational agent & vaporizers made
rapid progress.
• Today we are able to administer set
concentrations accurately.

4. ANAESTHESIA MACHINE

5. ANAESTHESIA WORK STATION

6. POSITION OF THE VAPORIZERS

7. STANDBY VAPORIZERS

8. DESFLURANE VAPORIZER

9. DESFLURANE

10. What is vaporizers?
An instrument designed to….
• Facilitate change of liquid into vapor
• Add controlled amount of vapor in flow of
gases

11. Why vaporizer needed?
• Liquid Inhalational agents need to be
vaporized
• Widely differing properties of agents, hence
specific vaporizers
• Potent agents require accurate conc. control

12. BASIC PHYSICS
• Gas-It is a substance that appears in gaseous
state under standard condition of
temperature and atmospheric pressure
• Vapor - is the gaseous phase of the
agent,which is normally liquid at room
temperature and atmospheric pressure

13. CRITICAL TEMPERATURE
• Critical temperature: is the temperature below
which gas can be liquefied by applying
pressure.
• THE CRITICAL TEMPERATURE, GAS/VAPOR

14. BOILING POINT
• Boiling Point: Boiling point of liquid is the
temperature at which its vapor pressure is equal
to atmosphereic pressure.
Boiling point SVP
Halothane 50.2 243
Isoflurane 48.5 238
Sevoflurane 58.5 160
Desflurane 23.5 664

15. VAPORIZER CONSTRUCTION
• Specific heat of agent: Materials with high
specific heat are preferred in construction of
the vaporizers.
• Latent heat of Vaporization
• Thermal Conductivity: High thermal
conductivity is desirable in vaporizer
construction.

16. CLASSIFICATION
Based on regulating output concentration
• Variable bypass
• Measured flow
• Electronic vaporizers
Based on method of vaporization
• Flow over
• Bubble through
• Injection

17. CLASSIFICATIONS (Contd…..)
Based on method of temperature Compensation
• Mechanical thermocompensation
• Supplied heat
• Computerized thermocompensation
Based on location of the vaporizer
• Plenum
• Low resistance (Draw Over)
Based on agent specificity
• Agent specific
• Multiple agent

18. Automatic Temp. Compensating Devices
Bimetallic Strip Expansion element
Expansion or contraction
property of a special liquid
inside bellows used to control
the valve
Two metals of different coefficients of
thermal expansion are fixed together.
Depending upon VC temperature the
strip move away or towards control
valve.

20. OLD VAPORIZERS
MORTON’S EITHER INHALER
Draw over, flow over with wicks, concentration not
calibrated, temperature not compensated, agent
specific.

21. OPEN DROP METHOD
Draw over, flow over without wicks,
concentration not calibrated, temperature
not compensated, multiple agent.

22. EPSTIEN MACINTOSH OXFORD
(E.M.O.)
Draw Over, Concentration calibrated,Flow over,
Temperature compensated by water jacket and agent specific,
can be used any where.

23. GOLDMANS VAPORIZER
Plenum or Draw over type ,variable bypass, flow
over, temperature not compensated, concentration
poorly calibrated, multiple agent, both inside and
outside circle.

24. BOYLES BOTTLE
Plenum type, variable bypass, flow over or bubble through,
concentration poorly calibrated, temperature not
compensated, agent specific, out of circle.

25. TEC - 2
Plenum type, concentration poorly calibrated, flow over with wicks,
temperature compensated, out of circle and agent specific.

26. TEC - 3
Plenum type, variable by pass, flow over with wicks, temperature
compensated, concentration calibrated, out of circle, agent specific.

27. TEC - 4
Plenum type, variable bypass, flow over with wicks, temperature
compensated, concentration calibrated, out of circle, agent specific.

28. NEWER VAPORIZER
TEC 5
Plenum type, concentration calibrated, variable bypass,
flow over with wicks, out of circle, agent specific with keyed filling.

29. TEC - 7
Concentration calibrated, plenum type, Variable bypass,
Flow over with wicks, Temperature compensated,
out of circuit, agent specific

30. TEC - 7
The innovative non-spill system in the Tec.7
vaporizer limits movement of liquid agent if
the vaporizer is lifted or inverted. This
protects its internal components and helps to
maintain output within clinically acceptable
limits.

31. TEC – 6 DESFLURANE VAPORIZER
It is a electrically heated, dual circuit gas/vapor blender,
constant-temperature, agent specific and out-of-circuit vaporizer.

32. PRINCIPLE OF DESFLURANE VAPORIZER

33. PRINCIPLE OF DESFLURANE
VAPORIZER (Contd…)

34. TEC - 6
Flow meters [1]. The fresh gas travels through pipe [2]. None of the fresh gas goes to the vaporizing chamber [4]. The vaporizing chamber is
electrically heated [3]. Using sensors for feedback, the temperature is kept very constant. The heating causes the Desflurane to become a gas
under pressure [4] and this travels down pipe [5]. The flow of Desflurane is resisted by two valves [6,13]. Valve [6] is the valve that you
control when you set the dial to a particular concentration. When you increase the concentration setting, the valve [6] opens a bit and lowers the
resistance, allowing more Desflurane to flow through. Valve [13] is an electronically controlled valve. Computer [12], the vaporizer's "brain", is
able to also alter the flow of Desflurane by controlling valve [13]. i.e. both you and the computer can adjust the desflurane injection rate. The
Desflurane then goes via pipe [7] and meets the fresh gas at [8]. The Desflurane mixes with the fresh gas [8] and a final concentration emerges
from the exit of the vaporizer [9].Fresh gas flow resistor (10), Fresh gas flow & Desflurane vapor balancing unit(11)

35. THE GE ALADIN CASSETTE VAPORIZER
It is a electronically controlled, variable bypass, constant-temperature,
multiple agent specific, and out-of-circuit vaporizer.

36. SAFETY FEATURES
• Select – TEC mount
• Filling devices
• Interlocking
• Colour coding

37. FILLING DEVICES
• Easy fill system
• Funnel fill
• quick fill.

38. The male adaptor that fits into the vaporizer filler
receptacle.

39. CAP OF BOTTLE REMOVED

40. Quick fill system

41. COLOR CODING OF VAPORIZERS
• ISOFLURANE SEVOFLURANE HALOTHANE
PURPLE YELLOW RED

42. HAZARDS OF VAPORIZERS
• Incorrect agent
• Tipping
• Simultaneous inhaled agent administration
• Overfilling
• Leaks
• Electronic failure
• Pumping effect
• Pressurizing effect

43. PUMPING EFFECT

44. CONCLUSION
• Proper maintenance will help to deliver the
accurate concentrations of the anaesthetic
vapor.
• In the future anaesthetic depth sensor may be
available as an integral part of the vaporizer.

45. THANK YOU