This document discusses vaporizers, which are devices used to convert liquid anesthetic agents into vapor for delivery to patients. It covers the basic principles of vaporization, factors that affect vaporizer output concentration, different types of vaporizers classified by their design and operating characteristics, and standards for vaporizer design. The key points are that vaporizers precisely regulate anesthetic vapor concentrations, multiple factors influence output, and designs vary in things like temperature compensation, agent specificity, and positioning within the breathing circuit.

1. http://www.ppt-to-video.com Presenter : Dr Unnikrishnan P Coordinator : Dr C MadhusoodhananPillai Moderators : Dr SheelaRani Dr Ravi Vaporizers : 1

2. 1.DO YOU FEEL YOU NEED IT? 2.SOME IMPORTANT THINGS! 3.CLASSIFICATION 4.FACTORS AFFECTING VAPORIZATION 5.ASTM VAPORIZER STANDARDS 6.FILLING SYSTEMS 7.HAZARDS[lengthy class..is it a hazard?] 8.EVOLUTION

3. Why we need a vaporizer? Most volatile agents exist as liquid at room temp & atm pressure Vaporizers convert this liquid form to vapor phase And add a certain amount of this vapor to the anesthesia circuit... In precisely determined concentrations over a wide range of temperatures, pressures and carrier gas flowrates.

4. Who is inside the vaporizer? Let me introduce..I am a gas Below a certain temp,I am very flexible ; then I will exist in a form which is interconvertable between the liquid and gaseous states- this gaseous form is known as vapor. But above this temp, I am very rigid ; you cannot change me into a liquid now..yes now I am a perfect gas And I wont tell u the name of that temperature!

5. SO VAPOR IS THE GASEOUS PHASE OF A SUBSTANCE BELOW ITS CRITICAL TEMPERATURE Love’ [van der Waals forces] promotes the liquid state, whereas ‘hatred’ [ Kinetic energy] promotes vapor phase

6. Vapor Pressure This vapor exerts a pressure on its surroundings- VAPOR PRESSURE V.P.depends only on the liquid and temperature

8. Saturated Vapor Pressure Now we close the container;the escaping ‘vapor molecules’ now may collide with the liquid surface and reenter it..an equilibrium forms No of molecules reentering = no of molecules leaving SATURATED VAPOR PRESSUREis the partial pressure of the vapor phase of a substance when at equilibrium with its liquid phase (e.g. in a closed container). Increases rapidly as boiling point approaches.

10. Boiling Point You go on increasing the temperature The V.P. will increase At a point it equals the atm pressure B.P.OF A LIQUID IS THE TEMPERATURE AT WHICH ITS VAPOR PRESSURE IS EQUAL TO THE ATM PRESSURE Low atm pressure -> Low B.P. High SVP -> Low B.P.[..means I am very volatile]

11. PARTIAL PRESSURE A MIXTURE OF GASES IN A CLOSED CONTAINER WILL EXERT A PRESSURE ON THE WALLS OF THE CONTAINER. THE PART OF THE PRESSURE EXERTED BY ANY ONE GAS IN THE MIXTURE IS CALLED ITS PARTIAL PRESSURE DEPENDS ONLY ON THE TEMPERATURE THE HIGHEST PARTIAL PRESSURE THAT CAN BE EXERTED BY A GAS AT A GIVEN TEMPERATURE IS ITS VAPOR PRESSURE. IT IS AN ABSOLUTE VALUE.

12. VOLUMES PERCENT NO OF UNITS OF VOLUME OF A GAS IN RELATION TO A TOTAL OF 100 UNITS OF VOLUME FOR THE TOTAL GAS MIXTURE. IT EXPRESSES THE RELATIVE RATIO OF GAS MOLECULES IN A MIXTURE. MOST COMMONLY USED BUT UPTAKE & DEPTH OF ANESTHESIA ARE DIRECTLY RELATED TO PARTIAL PRESSURES PARTIAL PRESSURE/TOTAL PRESSURE= VOLUMES PERCENT/100

13. HEAT OF VAPORIZATION THE NUMBER OF CALORIES REQUIRED TO CONVERT 1GM OF LIQUID INTO A VAPOR OR NUMBER OF CALORIES REQUIRED TO CONVERT 1 ML OF LIQUID INTO A VAPOR IN A VAPORIZER, AS THE LIQUID AGENT VAPORIZES,HEAT IS LOST;SO TEMPERATURE DROPS,VAPOR PRESSURE DROPS = LESSER VOL. AGENT FOR THE CARRIER GAS TO TAKE AWAY↓OUTPUT Oh…tell me some method to supply heat! Else my patient will wake up @#%?

14. SPECIFIC HEAT THE QUANTITY OF HEAT REQUIRED TO RAISE THE TEMP OF 1gm OF THE SUBSTANCE BY 1⁰C IF ITS LOW, THE TEMPERATURE WILL NOT RISE GRADUALLY WHEN WE SUPPLY HEAT TO A VOLATILE AGENT IN ORDER TO REPLACE THAT LOST DUE TO VAPORIZATION IF ITS HIGH...NICE GUY..VERY OBEDIENT! IS THIS IMPORTANT IN ANY OTHER ASPECT? MATERIAL FROM WHICH VAPORIZER CONSTRUCTED

15. THERMAL CAPACITY AMOUNT OF HEAT STORED IN THE VAPORISER BODY. IT IS THE PRODUCT OF SPECIFIC HEAT AND MASS. A VAPORIZER CONSTRUCTED FROM A SUBSTANCE WITH HIGH THERMAL CAPACITY WILL CHANGE TEMP MORE SLOWLY AND SO IS PREFFERED

16. THERMAL CONDUCTIVITY SPEED WITH WHICH HEAT FLOWS THROUGH A SUBSTANCE; CU > AL > BRASS > STEEL >> GLASS. HIGHER THE THERMAL CONDUCTIVITY, BETTER THE SUBSTANCE CONDUCTS HEAT.

17. THERMOSTABILIZATION IS ACHIEVED BY CONSTRUCTING VAPORIZERS OF METALS WITH HIGH THERMAL CONDUCTIVITY (COPPER, BRONZE) TO MINIMIZE TEMPERATURE CHANGES WHEN THE VAPORIZER IS IN USE WICKS SHOULD BE IN CONTACT WITH THE METAL PART

18. GAS LAWS BOYLES LAW:AT CONSTANT TEMPERATURE, THE VOLUME OF A GIVEN MASS OF GAS VARIES INVERSELY WITH THE ABSOLUTE PRESSURE CHARLE’S LAW: AT CONSTANT PRESSURE, THE VOLUME OF A GIVEN MASS OF GAS VARIES DIRECTLY WITH THE ABSOLUTE TEMPERATURE AT CONSTANT VOLUME, THE ABSOLUTE PRESSURE OF A GIVEN MASS OF GAS VARIES DIRECTLY WITH THE ABSOLUTE TEMPERATURE

19. DALTON’S LAW OF PARTIAL PRESSURES IN A MIXTURE OF GASES THE PRESSURE EXERTED BY EACH GAS IS THE SAME AS THAT WHICH IT WOULD EXERT IF IT ALONE OCCUPIED THE CONTAINER

20. AVOGADRO’S HYPOTHESIS EQUAL VOLUMES OF GASES AT THE SAME TEMPERATURE AND PRESSURE CONTAIN EQUAL NUMBER OF MOLECULES THIS NO IS 6.023 X 10²³ THIS MUCH NO OF PARTICLES OF ANY GAS AT STP WILL OCCUPY 22.4 Ls

21. EXAMPLE : CALIBRATION MOLECULAR WT OF ISOFLURANE 184.5 CONTAIN AVOGADRO NO OF PARTICLES; WILL OCCUPY 22.4 Ls @ STP SUPPOSE O₂VAPORIZES 18.45 GM OF ISOFLURANE INTO 224 L =0.1 MOLE = WILL OCCUPY 2.24Ls BUT THIS IS VAPORIZED INTO 224 Ls SO CONCENTRATION OF ISOFLURANE = 2.24/224 = 1%

22. Q: WHICH LAW IS REPRESENTED HERE?

23. CLASSIFICATION OF VAPORIZERS

24. METHOD OF REGULATING THE OUTPUT CONCENTRATION CONCENTRATION CALIBRATED MEASURED FLOW

25. METHOD OF VAPORIZATION FLOW OVER BUBBLE THROUGH INJECTION SIMPLE

26. TEMPERATURE COMPENSATION THERMOCOMPENSATION SUPPLIED HEAT

27. SPECIFICITY AGENT SPECIFIC MULTIPLE AGENTS

28. POSITION VAPORIZER INSIDE CIRCUIT VAPORIZER OUTSIDE CIRCUIT

29. RESISTANCE PLENUM LOW RESISTANCE/DRAW OVER

30. BASIC DESIGN

31. METHOD OF REGULATING OUTPUT CONCENTRATION

32. CONCENTRATION CALIBRATED TOTAL FLOW FROM THE MACHINE PASSES THROUGH THE VAPORIZER. THIS IS SPLIT BY A VARIABLE RESISTANCE PROPORTIONATING VALVE INTO TWO: ONE PART[USUALLY MAJOR] FLOWS THROUGH THE BYPASS CHAMBER & THE OTHER [USUALLY SMALL] THROUGH THE VAPORIZING CHAMBER.

33. CONCENTRATION CALIBRATED AGENT CONCENTRATION IS CONTROLLED BY A DIAL CALIBRATED IN VOLUMES PERCENT VOLUME VAPOURISED - TYPICALLY 200 ML VAPOUR PER ML OF LIQUID ANAESTHETIC ML LIQUID USED/HOUR = 3 X % X FGF

34. IF WE DIAL A HIGH CONCENTRATION

35. IF WE DIAL A LOW CONCENTRATION

36. SPLITTING RATIO THE RATIO OF THE BYPASS GAS TO THE GAS GOING TO THE VAPORIZING CHAMBER IS CALLED THE SPLITTING RATIO. SPLITTING RATIO DEPENDS ON: THE RESISTANCE OF THE TWO PATHWAYS, WHICH INTURN DEPENDS ON THE VARIABLE ORIFICE OF THE INLET/OUTLET. TEMPERATURE OF THE LIQUID /CARRIER GAS. FLOW RATE OF GASES DENSITY OF THE PARTICULAR GAS ENTERING VAP CHAMBER. MOSTLY CARRIER GAS IS O₂

37. MEASURED FLOW VAPORIZERS THE VAPORIZER HEATS THE ANESTHETIC AGENT TO A TEMPERATURE ABOVE ITS BOILING POINT( SO IT BEHAVES AS GAS ) AND THIS IS THEN METERED INTO THE FRESH GAS FLOW. A MEASURED FLOW IS SENT BY A SEPARATE OXYGEN FLOW METER TO PASS TO THE VAPORIZER WITH THE OUTPUT BEING AT SVP FOR THE ANESTHETIC AGENT. IN ORDER TO DILUTE THIS OTHERWISE LETHAL CONCENTRATION, OUTPUT FROM THAT FLOWMETER IS COMBINED WITH GAS PASSING FROM THE MAIN FLOWMETER e.g. COPPER KETTLE, VERNI-TRIOL

38. MEASURED FLOW VAPORIZERS OPERATOR HAS TO SET THE FLOW TO THE VAPORIZER AND BYPASS WITH SEPARATE FLOWMETERS THIS MEANS THAT RESPECTIVE FLOWS HAVE TO BE CALCULATED FOR EACH AGENT FOR A GIVEN TEMPERATURE AND VAPOUR OUTPUT.

39. VAPORIZATION METHODS

40. FLOW OVER HERE THE CARRIER GAS PASSES OVER THE SURFACE OF A LIQUID. SURFACE AREA OF VAPORISATION CAN BE INCREASED BY USING WICKS.

41. FLOW OVER

42. FLOW OVER DUE TO CAPILLARY ACTION, THE ANAESTHETIC AGENT RISES INTO THE WICKS. THIS DRAMATICALLY INCREASES THE SURFACE AREA OF ANAESTHETIC AGENT EXPOSED TO THE FRESH GAS AND THEREBY IMPROVES THE EFFICIENCY OF VAPORISATION. CARRIER GAS CAN BE DIRECTED USING BAFFLES OR SPIRAL TRACKS THAT LENGTHEN THE GAS PATHWAYS OVER THE LIQUID.THIS INCREASES THE TIME AND AREA OF CONTACT.

43. FLOW OVER

44. BUBBLE THROUGH CARRIER GAS IS ALLOWED TO BUBBLE THROUGH THE LIQUID. SMALLER THE BUBBLE ,LARGER WILL BE THE SURFACE AREA. METHODS TO BREAK THE GAS INTO SMALL BUBBLES ARE AGITATION & SPLASHING. FACTORS INFLUENCING THE VAPORIZER OUTPUT : SIZE OF THE BUBBLE, DEPTH OF LIQUID, BUBBLING SPEED

45. INJECTION VAPORIZERS A KNOWN AMOUNT OF LIQUID AGENT OR PURE VAPOUR IS INJECTED INTO THE GAS STREAM TO PROVIDE THE DESIRED CONCENTRATION E.G. TEC 6 DESFLURANE VAPORIZER

46. TEMPERATURE COMPENSATION TO MAINTAIN A CONSTANT O/P FROM THE VAPORIZER, MECHANISMS TO COMPENSATE FOR THE FLUCTUATIONS IN TEMPERATURE ARE TO BE EMPLOYED

47. TEMPERATURE COMPENSATION

48. THERMOCOMPENSATION MOST VARIABLE BYPASS VAPORIZERS COMPENSATE FOR CHANGES IN VAPOR PRESSURE BY ALTERING THE SPLITTING RATIO. DONE BY USING A THERMOSENSITIVE ELEMENT [BIMETALLIC STRIP] INCORPORATED IN THE VAPORIZING CHAMBER OR BYPASS CHAMBER. SO, THE SPLITTING OF GAS IS CONTROLLED BY TWO VALVES: (1)THE DIAL WE SET (SPLITTING VALVE) AND (2)THE TEMPERATURE COMPENSATING VALVE

49. THERMOCOMPENSATION IN A BIMETALLIC STRIP, TWO METALS WITH VERY DIFFERENT COEFFICIENTS OF THERMAL EXPANSION ARE FIXED TOGETHER.

50. THERMOCOMPENSATION WHEN THE TEMPERATURE OF THE VAPORISING CHAMBER DROPS, THE BIMETALLIC STRIP BENDS AND MOVES AWAY. THIS REDUCES THE RESISTANCE TO FLOW AND THUS MORE FLOW OCCURS INTO THE VAPORISING CHAMBER.

51. SUPPLIED HEAT AN ELECTRIC HEATER CAN BE USED TO SUPPLY HEAT TO A VAPORIZER AND MAINTAIN IT AT A CONSTANT TEMPERATURE.E.G.TEC 6

52. RESISTANCE

53. PLENUM [Latin= fullness] VAPORIZERS WITH HIGH RESISTANCE WHICH DEPEND ON COMPRESSED GAS DRIVEN UNDER PRESSURE ARE CALLED PLENUM VAPORIZERS. e.g. BOYLE BOTTLE,COPPER KETTLE

54. DRAW OVER CARRIER GAS IS DRAWN THROUGH THE VAPORISER EITHER BY THE PATIENT’S OWN RESPIRATORY EFFORTS, OR BY A SELF-INFLATING BAG OR MANUAL BELLOWS DRAWOVER SYSTEMS OPERATE AT LESS THAN, OR AT AMBIENT PRESSURE FLOW THROUGH THE SYSTEM IS INTERMITTENT, VARYING WITH DIFFERENT PHASES OF INSPIRATION, AND CEASING IN EXPIRATION. A ONE-WAY VALVE PREVENTS REVERSE FLOW IN THE CIRCUIT. E.G. EMO

55. DRAW OVER HAVE A LOW INTERNAL RESISTANCE TO GAS FLOW SO THAT THEY MAY BE USED WITHIN THE BREATHING CIRCUIT, THE GAS FLOW BEING DRIVEN THROUGH THEM BY THE PATIENT'S BREATHING. THEY MAY BE USED IN A NON-REBREATHING DRAW-OVER APPARATUS, OR AS IN-CIRCUIT VAPORIZERS IN A CIRCLE ABSORBER SYSTEM. ARE USUALLY OF THE SIMPLE BOTTLE OR BOWL TYPE (E.G. THE OHIO 8 BOTTLE, GOLDMAN OR STEPHENS), BUT MORE ACCURATE, LOW RESISTANCE DRAW-OVER VAPORIZERS, SUCH AS THE PENLON OXFORD MINIATURE VAPORIZER (OMV) AND OHMEDA DRAW-OVER TEC VAPORIZERS, HAVE BEEN MANUFACTURED.

56. FACTORS AFFECTING VAPORIZER OUTPUT 1. FLOW THROUGH THE VAPORIZING CHAMBER: Varying the proportion of gas passing through the vaporizing chamber and bypass chamber 2.SURFACE AREA OF THE LIQUID GAS INTERFACE: Greater the surface area, more will be the vaporization. Bubble through > flow over

57. FACTORS AFFECTING VAPORIZER OUTPUT 3.TEMPERATURE: As temperature increase, output increase 4.TIME: Output concentration tend to fall over time

58. FACTORS AFFECTING VAPORIZER OUTPUT 5.GAS FLOW RATE: (A)At high flowrates,the gas leaving vaporization chamber is less saturated (B)Alters the total flow that passes through the vaporization chamber

59. FACTORS AFFECTING VAPORIZER OUTPUT 6. CARRIER GAS COMPOSITION: (a) changes in viscosity & density may affect the proportion of the total flow passing through the vaporization chamber (b)N₂O dissolves in the flow, thus altering the effective volume passing through the vaporization chamber

60. FACTORS AFFECTING VAPORIZER OUTPUT 7.BOILING POINT :HIGHER THE BOILING POINT,LESS WILL BE THE VAPOUR O/P. 8. AMBIENT PRESSURE : SVP IS SOLELY A FUNCTION OF TEMP. SO IF AMBIENT PRESSURE IS REDUCED,THE CONSTANT SVP BECOMES A GREATER PROPORTION OF THE TOTAL PRESSURE OUTPUT INCREASES. AGENTS WITH LOW BOILING POINTS ARE MORE SUSCEPTIBLE TO THE INFLUENCE OF AMBIENT PRESSURE

61. EFFECT OF LOW ATMOSPHERIC PRESSURE

62. CONCENTRATION CALIBRATED HIGH RESISTANCE PATHWAY THROUGH THE VAPORISING CHAMBER OFFERS LESS RESISTANCE, UNDER HYPOBARIC CONDITIONS AND SO A SLIGHT INCREASE IN VAPOR O/P OCCURS.

63. MEASURED FLOW HERE THE DELIVERED PARTIAL PRESSURE & VOLUME PERCENT INCREASES. AMOUNT OF INCREASE DEPENDS ON THE BAROMETRIC PRESSURE & THE VAPOR PRESSURE OF THE AGENT. CLOSER THE VAPOR PRESSURE IS TO BAROMETRIC PRESSURE, GREATER THE EFFECT.

64. EFFECT OF HIGH ATMOSPHERIC PRESSURE

65. CONCENTRATION CALIBRATED ATM PRESSURE INCREASESDENSITY OF GAS CHANGESMORE RESISTANCE TO FLOW OF GAS THROUGH THE VAPORIZING CHAMBERDECREASED VAPOUR O/P (PARTIAL PRESSURE & VOLUME PERCENT) EFFECT ON PARTIAL PRESSURE IS LESS DRAMATIC

66. MEASURED FLOW LOWER CONCENTRATION IN TERMS OF PP/VOLUME PERCENT

67. EFFECT OF INTERMITTENT BACK PRESSURE

68. EFFECT OF INTERMITTENT BACK PRESSURE WHEN ASSISTED OR CONTROLLED VENTILATION IS USED ,THE POSITIVE PRESSURE GENERATED DURING INSPIRATION IS TRANSMITTED FROM THE BREATHING SYSTEM BACK TO THE MACHINE & SOME WAY MAY BE TRANSMITTED TO THE VAPORIZERS. ALSO SEEN WITH THE USE OF OXYGEN FLUSH 2 EFFECTS ARE SEEN:

69. PUMPING EFFECT THE INCREASE IN VAPORIZER OUTPUT CONCENTRATION DUE TO BACK PRESSURE

70. PUMPING EFFECT When the bag is squeezed ,pressure is transmitted back into both, the "by pass" channel and also to the vaporising chamber. The fresh gas tries to move forward and gets compressed both in the 'by pass' channel and the vaporising chamber. However, the vaporising chamber volume is much larger than the 'by pass' channel volume, and thus, more fresh gas gets compressed into it than into the 'by pass' channel.

71. PUMPING EFFECT This extra fresh gas that enters the vaporising chamber collects anaesthetic vapor

72. PUMPING EFFECT when the positive pressure is suddenly released (expiration) the previously compressed gases now suddenly expands in all directions. Some of the rapidly expanding gas (containing vapor) enter the inlet of the vaporiser and cross over into the 'by pass' channel

73. PUMPING EFFECT Normally, a vaporiser 'by pass' channel does not have vapor. So this vapor due the 'pumping effect' is additional. When this 'by pass' vapor flows across to the exit, it meets the vapor from the vaporising chamber. The addition of the 'by pass' vapor to the vapor from the vaporising chamber raises the final concentration of anaesthetic delivered. i.e. The 'pumping effect' increases the delivered concentration of anaesthetic agent.

74. PUMPING EFFECT SEEN ESPECIALLY WHEN CARRIER GAS IS LOW AGENT IN VAPORIZING CHAMBER IS LOW DIAL SETTING IS LOW PRESSURE FLUCTUATIONS ARE HIGH & FREQUENT.

75. PUMPING EFFECT MECHANISM IN MEASURED FLOW: GAS FLOW TO THESE VAPORIZERS BECOME SATURATED WITH VAPOUR & IS JOINED BY GAS FROM OTHER FLOWMETER,WHICH DILUTES ITS CONCENTRATION. WHEN BACK PRESSURE IS APPLIED,THERE IS RETROGRADE FLOW OF GAS SO THAT THE DILUTED GAS MIXTURE IS FORCED BACK INTO THE VAPORIZER.BECAUSE THIS GAS IS NOT SATURATED ,IT WILL THEN PICK UP ANESTHETIC VAPOUR.THE RESULT IS AN INCREASE IN O/P.

76. MODIFICATIONS TO MINIMISE PUMPING EFFECT KEEP THE VAPORIING CHAMBER SMALL OR INCREASING THE SIZE OF THE BYPASS CHAMBER .

77. MODIFICATIONS TO MINIMISE PUMPING EFFECT ADD LONG SPIRAL OR LARGE DIAMETER TUBE TO LEAD TO THE VAPORIZER CHAMBER.THE EXTRA GAS FORCED INTO THIS TUBE & SUBSEQUENTLY RETURNED TO THE BYPASS DOES NOT REACH THE VAPORIZING CHAMBER

78. MODIFICATIONS TO MINIMISE PUMPING EFFECT INCREASE RESISTANCE TO GAS FLOW THROUGH THE VAPORIZER.

79. MODIFICATIONS TO MINIMISE PUMPING EFFECT CHECK VALVE TO PREVENT BACKWARD FLOW OF GAS

80. MODIFICATIONS TO MINIMISE PUMPING EFFECT EXCLUDE WICKS FROM THE AREA WHERE THE INLET TUBE JOINS THE VAPORIZING CHAMBER. OUTLET TUBE MAY BE MADE LONGER SO THAT UNSATURATED GAS WILL HAVE TO PASS FURTHER BACK BEFORE PICKING UP ANESTHETIC VAPOUR. CONNECTIONS OF OXYGEN FLUSH VALVE LINE TO THE COMMON GAS OUTLET BE DESIGNED TO MINIMISE PRESSURE FLUCTUATIONS THAT MAY PRODUCE A PUMPING EFFECT LIMIT PRESSURE TRANSMITTED TO VAPORIZER TO <10KPa ABOVE NORMAL WORKING PRESSURE ,CONC NOT TO INCREASE >20%

81. PRESSURIZING EFFECT THE O/P OF SOME VAPORIZER USED IN CONJUNCTION WITH AUTOMATIC VENTILATOR HAS BEEN FOUND TO BE LOWER THAN DURING FREE FLOW TO ATMOSPHERE. MOSTLY SEEN WHEN HIGH FLOW LARGE PRESSURE FLUCTUATIONS LOW DIAL SETTINGS

83. PRESSURIZING EFFECT No of mol.s of the agent picked by carrier gas ∝ density of vapor mol.s in vaporizing chamber ∝ vapor pressure Increased pressure in vaporizer chamber compress carrier gas more mol.s/mL No of mols of the anesthetic agent same o/p ↓ed The Changes In Vaporizer O/P Caused By The Pumping Effect Usually Are Greater In Magnitude Than Those Associated With The Pressurizing Effect

84. 1988 ASTM MACHINE STANDARDS FOR VAPORIZERS A VAPORIZER MUST BE CAPABLE OF ACCEPTING A TOTAL GAS FLOW OF 15 lts/min FROM THE ANESTHESIA MACHINE AND IN TURN, DELIVERING A GAS FLOW WITH A PREDICTABLE CONC OF VAPOUR. THE EFFECTS OF THE CONDITIONS OF USE(VARIATIONS IN TEMP,PRESSURE,BACKPRESSURE,INPUT FLOW RATES)ON VAPORIZER PERFORMANCE MUST BE STATED IN CATALOGS.THE EFFECT OF CARRIER GAS COMPOSITION ON VAPORIZER O/P SHOULD ALSO BE SUPPLIED.

85. 1988 ASTM MACHINE STANDARDS FOR VAPORIZERS THE EXTENT TO WHICH TEMP & INFLOW RATES INFLUENCE THE VAPORIZER CONC MUST BE STATED. VAPORIZER MUST BE DESIGNED SO THAT IT CANNOT BE OVERFILLED WHEN IN NORMAL OPERATING POSITION. A SYSTEM THAT ISOLATES THE VAPORIZER FROM EACH OTHER & PREVENTS GAS FROM PASSING THROUGH THE VAPORIZER CHAMBER OF ONE VAPO & THEN THROUGH THAT OF ANOTHER MUST BE PROVIDED CONTROL MUST BE PROVIDED TO LIMIT THE ESCAPE OF ANESTHETIC VAPOUR FROM THE VAP CHAMBER INTO THE FRESH GAS ,SO THAT THE DELVERED CONC IS <0.1% WHEN THE VAPORIZER IS TURNED OFF

86. 1988 ASTM MACHINE STANDARDS FOR VAPORIZERS ALL THE VAPORIZER KNOB MUST TURN COUNTER CLOCKWISE TO INCREASE THE CONC. VAPORIZER MUST BE PROVIDED WITH A LIQUID LEVEL INDICATOR VISIBLE FROM THE FRONT OF THE MACHINE THE VAPORIZER MUST PERMIT MAXIMAL CALIBRATED FLOWS OF O2&N20 IN AN ON & OFF POSITIONS WITH THE VAPORIZER FILLED TO THE MAXIMUM SAFE INDICATED LEVEL WITHOUT DISCHARGING LIQUID THROUGH ITS OUTLET WHEN IT IS MOUNTED & USED IN ACCORDANCE WITH THE MANUFACTURERS INSTRUCTIONS

87. 1988 ASTM MACHINE STANDARDS FOR VAPORIZERS VAPORIZER UNSUITABLE FOR USE IN THE BREATHING SYSTEM MUST ‘VE NONINTERCHANGEABLE 23MM FITTINGS.THE 22MM OR 15MM FITTINGS CANNOT BE USED.THE INLET OF THE VAPORIZER MUST BE MALE,OUTLET MUST BE FEMALE & THE DIRECTION OF GAS FLOW MUST BE MARKED WHEN 23MM FITTINGS ARE USED. VAPORIZER SUITABLE FOR USE IN THE BREATHING SYSTEM MUST ‘VE STANDARD 22MM FITINGS OR SCREW THREADED,WEIGHT BEARING FITTINGS WITH INLET FEMALE & OUTLET MALE.THE INLET &OUTLET PORTS MUST BE MARKED,THE DIRECTION OF GAS FLOW MUST BE INDICATED BY ARROWS & VAPORIZER MUST BE MARKED “FOR USE IN BREATHING SYSTEM”.

88. 1988 ASTM MACHINE STANDARDS FOR VAPORIZERS ALL VAPORIZER LOCATED IN THE FRESH GAS CIRCUIT BE CONCENTRATION CALIBRATED & THAT THE CONTROL OF VAPOUR CAN BE PROVIDED BY MEANS OF CALIBRATED KNOBS OR DIALS.THE MEASURED FLOW SYSTEMS NOT MENTIONED IN THE STANDARDS ARE THEREFORE NOW CONSIDERED BY MOST TO BE OBSOLETE ,ALTHOUGH MILITARY FIELD ANESTHESIA MACHINE STILL USE SUCH SYSTEM

89. AGENT SPECIFIC FILLING SYSTEMS

90. AGENT SPECIFIC FILLING SYSTEMS A VAPORIZER DESIGNED FOR A SINGLE AGENT BE FITTED WITH A PERMANENTLY ATTACHED AGENT SPECIFIC DEVICE TO PREVENT ACCIDENTAL FILLING WITH A WRONG AGENT. THEY PREVENT ACCIDENTAL FILLING WITH THE WRONG AGENT REDUCE AIR POLLUTION PREVENT CONTAMINANTS ENTERING VAPORIZATION CHAMBER TYPES KEYED FILLING SYSTEM SCREW CAPPED FILLING SYSTEM PIN SAFETY SYSTEM

91. AGENT SPECIFIC FILLING SYSTEMS BOTTLE COLLAR ATTACHED AT THE NECK OF THE BOTTLE. 2 PROJECTIONS,ONE THICKER THAN THE OTHER ARE THERE. THIS MATES WITH THE CORRESPONDING INDENTATIONS ON THE BOTTLE ADAPTOR.

92. AGENT SPECIFIC FILLING SYSTEMS

93. AGENT SPECIFIC FILLING SYSTEMS BOTTLE ADAPTOR AT ONE END IS 1) THE BOTTLE CONNECTOR WITH A SCREW THREAD TO MATCH THE THREAD ON THE BOTTLE 2)SKIRT THAT EXTENDS BEYOND THE SCREW THREADS 3)SLOTS THAT MATCH THE PROJECTIONS ON THE BOTTLE COLLAR

94. AGENT SPECIFIC FILLING SYSTEMS AT THE OTHER END IS 1.THE MALE ADAPTOR THAT FITS INTO THE VAPORIZER FILLER RECEPTACLE. 2.A SHORT LENGTH OF PLASTIC TUBING WITH 2 INNER TUBES CONNECTS THE ENDS. 3.THE TUBE ALLOWS THE BOTTLE TO BE HELD HIGHER OR LOWER THAN THE VAPORIZER.

95. AGENT SPECIFIC FILLING SYSTEMS MALE ADAPTER HAS A GROOVE ON ONE SIDE TO PREVENT THE PROBE FROM BEING PLACED IN THE INCORRECT VAPORIZER TWO HOLES ON THE OTHER SIDE LARGER FOR AGENT TO LEAVE / ENTER SMALLER FOR AIR

96. AGENT SPECIFIC FILLING SYSTEMS FILLER RECEPTACLE [FILLER SOCKET/VAPORIZER FILLER UNIT/FILL & DRAIN SYSTEM] MUST PERMIT THE INSERTION OF THE INTENDED BOTTLE . MUST ‘VE A MEANS OF TIGHTENING THE MALE ADAPTER ,TO FORM A TIGHT SEAL.

97. AGENT SPECIFIC FILLING SYSTEMS FILLER RECEPTACLE MUST ‘VE A MEANS OF SEALING THE ADAPTOR WHEN BOTTLE ADAPTOR NOT INSERTED. SINGLE PORT FOR FILLING & DRAINAGE. A VALVE ATTACHED TO A KNOB AT THE TOP CONTROLS THE OPENING INTO THE VAPORIZER A BALL VALVE IN THE AIRLINE OCCLUDES THE AIR PORT AFTER THE VAP IS FILLED TO PREVENT OVERFILLING & FLOODING OF AIRLINE WITH THE AGENT.

98. AGENT SPECIFIC FILLING SYSTEMS FILLING CAP OF BOTTLE REMOVED ADAPTER SCREWED TO THE COLLAR

99. AGENT SPECIFIC FILLING SYSTEMS FILLING VAPORIZER TURNED OFF PLUG REMOVED BOTTLE WITH ADAPTER INSERTED SUCH THAT THE GROOVES MATCH; [TUBE BENT SUCH THAT BOTTLE IS BELOW INLET]

100. AGENT SPECIFIC FILLING SYSTEMS FILLING RETAINING SCREW TIGHTENED FILL VALVE [VENT] OPENED BOTTLE HELD HIGH AIR FROM THE VAPORIZER DISPLACED BY THE LIQUID MOVES THROUGH THE OTHER TUBE AND ENTERS THE AIR SPACE INSIDE THE BOTTLE GENTLE UP AND DOWN MOTION MAY HELP

102. AGENT SPECIFIC FILLING SYSTEMS DRAINING ADAPTER ATTACHED TO BOTTLEFILLER PLUG REMOVED MALE ADAPTOR INSERTEDRETAINING SCREW TIGHTENEDBOTTLE HELD BELOW THE RECEPTACLE DRAIN VALVE OPENEDDRAINED SCREW LOOSENEDADAPTOR REMOVEDFILLER PLUG REINSERTED

103. AGENT SPECIFIC FILLING SYSTEMS-PROBLEMS 1.DIFFICULTY IN FILLING 2.MISALIGNMENT OF ADAPTOR IN FILLER RECEPTACLE . 3.ADAPTOR NOT SEALING AT THE BOTTLE END . 4.LEAK IN THE BOTTLE ADAPTOR 5.AIR BUBBLES. 6.LOST BOTTLE ADAPTOR 7.FAILURE OF KEYED SYSTEM 8.LIQUID LEAKS 9.INCOMPLETE EMPTYING

104. AGENT SPECIFIC FILLING SYSTEMS-PROBLEMS 10.VAPORIZER TIPPING IF FILLER RECEPTACLE ON VAPORIZER EXTENDS BEYOND THE BASEIT CANNOT BE SET UPRIGHT ON A FLAT SURFACETHIS CAN CAUSE TIPPING PREVENTED BY SETTING THE VAPORIZER RECEPTACLE AT THE EDGE OF THE SURFACE OR A RING CAN BE FITTED AT THE BASE THAT EXTENDS BELOW THE PROJECTION OF THE FILLER REEPTACLE . 11.POOR DRAINAGE 12.BROKEN INNER TUBE

105. LOCATION BETWEEN THE FLOWMETERS & COMMON GAS OUTLET BETWEEN THE COMMON GAS OUTLET & BREATHING SYSTEM IN- SYSTEM VAPORIZERS

106. HAZARDS INCORRECT AGENT LOW OUTPUT OR HIGH OUTPUT MISPLACING DESFLURANE DANGEROUS GAS ALLOWEDTO FLOW THRUGH IT UNTIL NO AGENT DETECTED IN THE OUTFLOW

107. HAZARDS TIPPING LIQUIDFROM VAPORIZING CHAMBERBYPASS/OUTLETHIGH OUTPUT DRAINED BEFORE MOVING

108. HAZARDS OVERFILLING IN MAJORITY, THE DESIGN OF THE FILLING PORT AND AGENT SPECIFIC FILLING SYSTEMS PREVENT THIS DURING FILLING DO NOT: TURN THE DIAL ON/ UNSCREW THE BOTTLE ADAPTOR

109. HAZARDS REVERSED FLOW INLET MALE & OUTLET FEMALE INCRESED OUTPUT CONCENTRATION DIAL IN WRONG POSITION CONTAMINANTS IN VAPORIZING CHAMBER PHYSICAL DAMAGE OBSTRUCTION TO FRESH GAS FLOW INTERLOCK MALFUNCTION LEAKS

110. Evolution of vaporizers MORTONS ETHER INHALER 1846,OCT 16

111. SNOW ETHER INHALER 1847 It incorporates the basic principles of vaporization He knew the importance of ambient temperature on vaporization Had a metal box as bath for water at 50-60⁰F

112. CLOVER PORTABLE REGULATING ETHER INHALER 1877 By Joseph Clover [surgeon ->anesthetist] For ether & chloroform Can regulate the amount of vapor inhaled, rapid onset,no valves Metal sphere with ether; sphere rotated around a central tube through which patient inhales Model for Ombredanne’s inhaler Markings not related to output concentration

113. CLOVER GIVING CHLOROFORM

114. VERNON HARCOURT CHLOROFORM INHALER 1903 BY AG Vernon Harcourt For chloroform [amount inhaled <2%,hence safe] Simple, accurate, portable Apparatus could be worn around the chloroformist’s neck Danger! Don’t lean to take something from the floor

115. MORE BURDENS ON THE NECK………

116. OMBREDANNE ETHER INHALER 1908 Louis Ombredanne [plastic Sxn] Strongly argued for air! Against ether! Criticized Clovers ‘useless’ water chamber Had a modern bag [made from cow’s caecum]

117. OMBREDANNE INHALER

118. SOMNOFORM INHALER 1908 SOMNOFORM MIXTURE: Ethyl chloride+ Methyl chloride+ Ethyl bromide [60:35:5]

119. OPEN DROP MASKS ESMARCH 1879 SCHIMMELBUSCH 1890 YANKAUER MASK 1910 For agents like ether,chloroform, divinyl ether & ethyl chloride Mask was covered with flannel/gauze onto which,these agents were poured

120. YANKAUER’S MASK

121. YANKAUER’S MASK (1)Yankauer’s facemask with mesh and (2)removable spiral wire collar for holding in place, lint or gauze, on to which agents such as ether &chloroform were applied Length 15cm Width 7.9cm Depth 5.5cm Materials: Copper alloy, chrome plate

122. SCHIMMELBUSCH MASK

123. SCHIMMELBUSCH MASK SCHIMMELBUSCH FOLDING FACE MASK with a hinged frame for holding gauze/lint in place Height : 18.3cm Width 11.3cm depth 7.3cm Materials: copper alloy, nickel plate For ether 16 layers of gauze; ether dropped over the whole area

124. SCHIMMELBUSCH MASK Heat of vaporization high;so require much latent heat Mask cools & water vapour condenses on it and freezes Increased resistance and reduced rate of vaporisation Keep a second mask and fresh gauze in supply There should be a Drop Bottle to drop the agent into the mask

125. SCHIMMELBUSCH MASK For Chloroform, 12 layers of gauze Liquid agent poured over one half of the mask in order to ensure that air is entrained to avoid high concentration Cover the patients face with a piece of cloth of 25X20 cm. In this make a central hole to expose patients nose and mouth. This prevents vapor or liquid from entering eyes. Also reduces the amount of air drawn in

126. OXFORD VINETHENE INHALER 1940 Used for Divinyl ether

127. OXY-COLUMBUS TRILENE INHALER 1950 By Hans Hosemann Analgesic properties of Trichloroethylene utilized in labour,dressingchanges,dentistry,ENT Held over nose / mouth Chain passed around patients neck Vaporization by warmth of patients hand Inhaler fell from hand as she become unconcious

128. DUKES TRILENE INHALER 1952 Draw over Non rebreathing mechanism to prevent CO2 accumulation Trileneupto 0.5% ; conc. Controlled by the patient Wrist strap to prevent falling away Mainly in Rx of pain during child birth

129. DUKES TRILENE INHALER

130. DRAGER BAR TRILENE INHALER 1955 Safe self administration Overdosing practically impossible Max 1%

131. PENTHRANE ANALGIZER 1968 For Methoxyflurane Light weight Disposable No face mask

132. SKINNERS WIRE FACE MASK 1862 By Thomas Skinner , an Obstetric Physician For chloroform Wire frame and gauze Can be folded and kept in pocket

133. JUNKERS CHLOROFORM BOTTLE FIRST BLOW OVER APPARATUS Air blown by hand held bellows through glass bottles containing chloroform Modified later with wire face mask,which is safer

134. OGSTON INHALER Mask is like that of Schimmelbusch Surmounted by a wire frame Around this a gauze could be erected Semiopen method, economical use of ether

135. BOYLES BOTTLE PARTS:(1)VAPORIZING BOTTLE 300 mL (2) METAL TOP INCORPORATING CONTROLS (3)LEVER,PLUNGER WHICH IS CHROME PLATED (4)STOPPER & RETAINING CHAIN

136. BOYLES BOTTLE Stoper cork should be air tight It is retained by small chain Top of cork insulated to avoid electric spark

137. BOYLES BOTTLE

138. BOYLES BOTTLE Copper in U-Tube & hood of plunger prevents decomposition of ether Before operating the ether vaporizer, the filling orifices should be kept open for some seconds and then closed ;otherwise high concentration may be delivered Temperature compensated by copper plate or water bath

139. BOYLES BOTTLE: ETHER-CHLOROFORM-TRILENE

140. PINSON ETHER BOMB Avoids carrying of complex machines & heavy cylinders 100% warmed ether vapor

141. TRILENE POCKET VAPORIZER 1941 Self administration of trilene in war Small, non spillable, easy to use Easily refilled .3-.4% vapor @ room temperature

142. OXFORD MINIATURE VAPORIZER[OMV] Advantages Small, portable, simple, less servicing May be drained of one agent & filled with the other Detachable scales for several agents

143. OXFORD MINIATURE VAPORIZER[OMV] PARTS: ETHER PLACED IN INNER CONTAINER SURROUNDED BY CRYSTALS OF HYDRATED CaCl₂ MIXING CHAMBER CONTROL VALVE 50 Ml CAPACITY WEIGHT WITH WATER 1060gm

144. OXFORD MINIATURE VAPORIZER[OMV] hot water jackets causes melting of CaCl₂. It cools and solidifies and relases heat of crystalisation. This heat absorbed by ether vaporisation  mixed with O₂ in the mixing chamber  delivered Prone to tipping Screw cap filling Back pressure compensation by circuit valves

145. TRISERVICE ANESTHESIA APPARATUS Consists of 2 OMVs + LAERDEL folding manual resuscitator quick change from one to other possible, high concentration of each agent can be obtained All except O₂ cylinder housed in a box Dropped from a parachute in war fields

146. EPSTEIN MACINTOSH OXFORD VAPORIZER 1952 [EMO]

147. EPSTEIN MACINTOSH OXFORD VAPORIZER 1952 [EMO]

148. EPSTEIN MACINTOSH OXFORD VAPORIZER 1952 [EMO]

149. EMO-INTERIOR PARTS VAPORIZATION CHAMBER BYPASS CHAMBER MIXING CHAMBER CONTROL VALVE METAL BELLOWS CONTAINING LIQUID IN VAPORIZATION CHAMBER WICKS AROUND VAPORIZING CHAMBER WALL WATER JACKET OF 1250 ML DISTILLED WATER ALUMINIUM OR STEEL CONTROL VALVE AT THE MOUTH OF THE VAPORIZATION CHAMBER

150. EMO-INTERIOR PARTS

151. EMO- HOW IT WORKS CONTROL VALVE CONTROLS AIR FLOW INTO THE CHAMBER METAL BELLOWS IS THE THERMOCOMPENSATOR USED WITH OXFORD INFLATING BELLOWS A MAGNET IS USED TO IMMOBILIZE NON REBREATHING VALVE DURING SPONTANEOUS RESPIRATION IN CONTROLLED VENTILATION, NO MAGNET IS USED APL VALVE NEAR PATIENT END KEPT OPEN FOR EXPIRATION

152. EMO- HOW IT WORKS TIPPING PREVENTED BY ON-OFF VALVES BACK PRESSURE COMPENSATION PREVENTED BY CIRCUIT VALVES ADVANTAGES: LOW COST, PORTABLE,CAN BE USED IN HIGH ALTITUDES AS IT AUTOMATICALLY ADJUSTS FOR CHANGES IN BAROMETRIC PRESSURES IN TROPICS IT HAS TO BE COOLED BEFORE USE IN CLOD TEMPERATURE, ANTIFREEZE SOLUTION 25% GLYCOL USED IN WATER JACKET AIR IS THE CARRIER

153. EMO HOW IT WORKS

154. GOLDMAN VAPORIZER

155. GOLDMAN VAPORIZER-PARTS SMALL GLASS POT METAL HEAD INLET & OUTLET CONTROL LEVER ON TOP OF METAL HEAD CAPACITY 30 ML MAX CONCENTRATIO 2±0.5%

156. GOLDMAN VAPORIZER

157. Goldman Adjustment is made by means of a ratchet type control valve. The glass jar is screwed on to the body and can be quickly detached for easy filling

158. ROWBOTHOM VAPORIZER MODIFICATION OF GOLDMAN VAPORIZER

159. FOREGGER COPPER KETTLE 1952

160. FOREGGER COPPER KETTLE 1952 COPPER VESSELHIGH HEAT CAPACITY & THERMAL CONDUCTIVITY GAS BREAKS AS IT PASSES THROUGH THE DIFFUSER AND GETS FULLY SATURATED IN ITS PASSAGE THROUGH THE LIQUID HIGH DEGREE OF ACCURACY HALOX VAPORIZER- MODIFICATION

162. TEMPERATURE COMPENSATION IN BOYLE BOTTLE IS BY ETHYL CHLORIDE

163. WHEN I SPEAK OF COPPER KETTLE THE FIRST WORD THAT COMES TO MY MIND IS MEASURED FLOW

164. GOLDMAN IS A FLOW OVER TYPE VAPORIZER

165. GOLDMAN OMV EMO BYLES BOTTLE; ALL ARE DRAW OVER TYPE

166. TEMPERATURE STABILISATION AND COMPENSATION ARE THE SAME

167. NO TEMPERATURE COMPENSATION IN GOLDMAN BOYLE BOTTLE

168. COPPER KETTLE: TEMPERATURE COMPENSATION IS MANUAL

169. BIMETALLIC STRIP IN BYPASS CHAMBER IN ALLADIN CASSETTE

170. GOLDMAN IS AN AGENT SPECIFIC VAPORIZER

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