Vaporizers and Scavenger systems 2024 PDF

AND SCAVENGER SYSTEMS Z AL EZ D NP , C R N A VICENTE GON I NT ER NA TI ON AL FLORIDA UNIVERSITY I A NUR S E P R OG RAM ANESTHES SCAVENGER SYSTEMS OBJECTIVES: STATE THE IMPORTANCE OF THE SCAVENGING SYSTEM IN MODERN ANESTHESIA MACHINES....

AND SCAVENGER SYSTEMS Z AL EZ D NP , C R N A VICENTE GON I NT ER NA TI ON AL FLORIDA UNIVERSITY I A NUR S E P R OG RAM ANESTHES SCAVENGER SYSTEMS OBJECTIVES: STATE THE IMPORTANCE OF THE SCAVENGING SYSTEM IN MODERN ANESTHESIA MACHINES. BECOME FAMILIAR WITH THE DIFFERENT TYPES OF SCAVENGER SYSTEMS, ADVANTAGES AND DISADVANTAGES OF EACH. TO PERFORM A SCAVENGER CHECK DURING YOUR MACHINE CHECK. SCAVENGER SYSTEMS IMPORTANCE OF THE MODERN ANESTHESIA MACHINE SCAVENGER SYSTEM. PREVENT CONTAMINATION OF OR ENVIRONMENT BY ANESTHETIC GASES. PROTECT OR AND ANESTHESIA STAFF FROM ANESTHESIA GASES. AMOUNT OF EXPOSURE REGULATED BY NIOSH AND OSHA. LIMIT EXPOSURE TO 2 PPM OF HALOGENATED AGENTS (0.5) PPM IF USED WITH N2O. AND 25 PPM OF N2O. Concerns Over Trace Concentrations of Anesthetic Gases 01 02 03 04 Health Risks of Occupational Safety Technologies for Pollution Prevention in Anesthetic Gases Regulations Reducing Waste Gas Clinical Decision-Making Concerns regarding trace Occupational safety Technologies for reducing It is essential to prioritize concentrations of anesthetic regulations emphasize the waste gas release, such as pollution prevention in clinical gases have been raised due to importance of monitoring and scavenging systems and decision-making by avoiding potential health risks managing trace levels of proper ventilation, play a nitrous oxide as a carrier gas. associated with long-term anesthetic gases to ensure the crucial role in minimizing trace exposure in operating rooms. safety of operating room concentrations of anesthetic Using lower fresh gas flow personnel. gases in the operating room. rates and considering Studies have shown that alternative drug combinations exposure can lead to adverse Standards by organizations Recommendations for can minimize environmental health effects, including like NIOSH and OSHA in the US monitoring anesthetic gases impact. pregnancy complications, liver address occupational safety include using sampling and kidney disease, cancer, concerns related to exposure methods like infrared and congenital abnormalities. to waste anesthetic gases. analyzers to ensure compliance with exposure limits and to detect any leaks or contamination. / 1 Occupational Safety and Health Regulations in the US Introduction to the Follows due procedure to implement Occupational Safety and standards. Health Act of 1970 NIOSH Recommended Passed by the U.S. Congress to ensure safe and healthful working conditions. Standards Led to the establishment of NIOSH and Control occupational exposure to OSHA. halogenated anesthetic agents and nitrous oxide. Role of NIOSH Monitor trace levels of anesthetic gases in the operating room. Conducts and funds research on exposure hazards. Ensuring Compliance Recommends safety standards to protect workers. Regular maintenance of equipment and monitoring of exposure levels. Funded studies like the National Survey of Occupational Disease Among Adherence to safety protocols. Operating Room Workers. Guidelines provided by the U.S. Department of Labor and OSHA. Role of OSHA Compliance minimizes health risks Enacts and enforces safety standards associated with exposure to waste recommended by NIOSH. anesthetic gases. Anesthetic Gas Management: Ensuring Safety and Compliance / 3 Sources of Anesthetic Gas Contamination 01 02 03 04 05 Adjustable Pressure- High- and Anesthesia Cryosurgery Units Miscellaneous Limiting Valve Intermediate- Ventilator Sources of Pressure Systems of Contamination The APL valve in the the Anesthesia These systems include the The anesthesia ventilator Cryosurgery units can Other potential sources anesthesia breathing circuit Machine N2O central supply pipeline can be a source of release waste anesthetic include faulty anesthesia serves as an outlet for and reserve tanks. anesthetic gas gases, particularly nitrous circuits, obstruction in gas waste anesthetic gases contamination if not oxide, into the atmosphere. scavenging systems, and during ventilation. Pressure ranges from 26 to properly maintained. malfunctions in gas 750 pounds per square inch If not adequately scavenging equipment. Potentially releases over 5 gauge. Leaks in the system can scavenged or controlled, liters of gas per minute. release gases into the they pose a risk of These issues can lead to Potential leaks contribute operating room contamination in the OR unintended release of Leakage through this valve to OR contamination. environment. and surrounding areas. gases and compromise the can significantly contribute safety of healthcare to anesthetic personnel. contamination in the operating room. Anesthetic Gas Management: Ensuring Safety and Compliance / 4 SCAVENGING SYSTEMS ACTIVE- REQUIRE SUCTION PASSIVE- RELY ON PASSIVE FLOW JOINT COMMISSION REQUIRES ACTIVE SYSTEM YOU MAY FIND PASSIVE SYSTEMS IN SOME SMALLER INSTITUTIONS SCAVENGING SYSTEMS PROPERTIES NOT AFFECT DYNAMICS OF BREATHING NOT AFFECT OXYGENATION OF THE PATIENT SCAVENGING SYSTEMS COMPONENTS RELIEF VALVE CONDUCTING TUBING INTERFACE DISPOSAL LINE  Types Open SCAVEN GER Closed SYSTEM S Active Passive  Open vs. Closed Interface SCAVEN Open systems vent GER directly to the outside and require SYSTEM Closed systems are no valves. S closed to the outside and therefore require negative and positive pressure relief valves to protect the patient. SCAVENGER SYSTEMS Passive systems vent Active the gases far systems are Active vs. away enough to connected to Passive prevent the hospital contaminatio vacuum line. n of the OR environment. SCAVENGER SYSTEMS COMPONENTS GAS COLLECTION SYSTEM, APL VALVE VENTILATOR RELIEF VALVE. 19 OR 30 MM. (DIFFERENT THAN VENTILATOR) SCAVENGING INTERFACE GAS DISPOSAL TUBING GAS DISPOSAL ASSEMBLY SCAVENGER SYSTEMS SUMMARY INTERFACE – OPEN, NEWER MODELS. CLOSED OLDER MODELS. ACTIVE – PASSIVE SUCTION VS. ATMOSPHERIC VENTING. MUST HAVE POSITIVE AND NEGATIVE PRESSURE RELIEF VALVES TO PREVENT PATIENT HARM FROM TOO MUCH PRESSURE OR VACUUM. SCAVEN GER SYSTE MS SCAVENGE R SYSTEM PASSIVE/ CLOSED SCAVENGE R SYSTEM ACTIVE/C LOSED SCAVENGER SYSTEM ACTIVE/OP EN HAZARDS MALFUNCTION TOO MUCH SUCTION NOT ENOUGH SUCTION VAPORIZ ERS OBJECTIVES DESCRIBE THE BASIC WORKINGS OF A MODERN VAPORIZER EXPLAIN HOW A MODERN VAPORIZER WORKS AND THE PRINCIPLES BEHIND THEM DESCRIBE FACTORS THAT AFFECT VAPORIZATION DESCRIBE FACTORS THAT AFFECT VAPORIZER OUTPUT VAPORIZERS CONVERT LIQUID ANESTHETIC INTO A VOLATILE INHALATION AGENT SHOULD BE CALIBRATED FOR ACCURACY OF DELIVERED CONCENTRATION BASED ON LAWS OF PHYSICS YOU MUST MEMORIZE THE CHEMICAL PROPERTIES OF THE VOLATILE AGENTS VAPORIZERS SATURATED VAPOR PRESSURES ARE TOO HIGH SVP OF SEVOFLURANE 160MMHG DIVIDE BY ATMOSPHERIC PRESSURE OF 760MMHG 160/760 (100)= 21% (THE MAC OF SEVO IS 2.1%) NEED TO DILUTE TO A CONCENTRATION THAT IS NOT LETHAL VAPORIZERS TYPES MEASURED FLOW (OBSOLETE AND NOT IN USE) THE FLOW THROUGH THE LIQUID IS MEASURED IT IS THEN DILUTED NEEDS TO BE CALCULATED EXAMPLE THE COPPER KETTLE , VERNITROL VAPORIZERS TYPES (CONT’D) CONCENTRATION CALIBRATED (MOST ARE VARIABLE BYPASS) DELIVER A SET CONCENTRATION BASED ON THE DIAL SETTING BASIC DESIGN GAS ENTERS VAPORIZER FLOW IS SPLIT (VARIABLE BYPASS) MAJORITY IS BYPASSED SOME ENTERS THE VAPORIZING CHAMBER SATURATED GAS LEAVES CHAMBER DILUTED BY BYPASS GAS DELIVERED TO PATIENT APPLIED PHYSICS VAPOR PRESSURE DALTON’S LAW (THE TOTAL PRESSURE OF A MIXTURE OF GASES IS EQUAL TO THE SUM OF THE PARTIAL PRESSURES OF THE COMPONENT GASES) BASED ON CHARACTERISTICS OF AGENT VARIES WITH TEMPERATURE APPLIED PHYSICS (CON’T) BOILING POINT VAPOR PRESSURE EQUALS ATMOSPHERIC PRESSURE, ALL LIQUID IS IN THE VAPOR PHASE LATENT HEAT OF VAPORIZATION HEAT REQUIRED TO CHANGE LIQUID INTO A VAPOR COMES FROM LIQUID AND ENVIRONMENT VAPOR PRESSURE- PRESSURE EXERTED ON WALLS OF A CONTAINER BY MOLECULES THAT BROKE AWAY FROM THE LIQUID SURFACE. EQUILIBRIUM WILL BE ACHIEVED IF TEMPERATURE REMAINS CONSTANT. ALL VOLATILE ANESTHETICS HAVE A SPECIFIC VAPOR PRESSURE. THE CONCENTRATION CAN BE CALCULATED FROM THE VAPOR PRESSURE ABOVE THE LIQUID.  VAPOR PRESSURE- PRESSURE APPLIED PHYSICS (CON ’T) EXERTED ON WALLS OF A CONTAINER BY MOLECULES THAT BROKE AWAY FROM THE LIQUID SURFACE. EQUILIBRIUM WILL BE ACHIEVED IF TEMPERATURE REMAINS CONSTANT. ALL VOLATILE ANESTHETICS HAVE A SPECIFIC VAPOR PRESSURE. THE CONCENTRATION CAN BE CALCULATED FROM THE VAPOR PRESSURE ABOVE THE LIQUID. VOLUMES PERCENT(VOL. %)- THE NUMBER OF UNITS OF VOLUME OF GAS IN RELATION TO A TOTAL OF 100 UNITS OF VOLUME FOR THE TOTAL GAS VOLUME. VAPORIZATION VAPOR: GAS PHASE OF A SUBSTANCE THAT IS LIQUID AT ROOM TEMPERATURE AND ATMOSPHERIC PRESSURE VAPORIZATION: CONVERSION OF LIQUID TO GAS (INSIDE VAPORIZER) VAPORIZATION DEPENDS ON: VAPOR PRESSURE OF AGENT TEMPERATURE OF ENVIRONMENT AMOUNT OF CARRIER GAS (N2O & O2) USED  SATURATED VAPOR LIQUID INSIDE CLOSED CONTAINER MOLECULES OF LIQUID BREAK AWAY AN PRESSURE ENTER SPACE ABOVE TO FORM A VAPOR AT CONSTANT TEMP: # MOLECULES ENTERING AND LEAVING LIQUID ARE EQUAL # MOLECULES IN VAPOR PHASE STAYS CONSTANT PRESSURE CREATED WHEN MOLECULES “BOMBARD” THE WALLS OF CONTAINERSATURATED VAPOR PRESSURE (SVP) VOLATILE ANESTHETIC AGENT (VAA): LIQUID THAT HAS TENDENCY TO CHANGE TO A VAPOR AT STANDARD TEMP & PRESS. HIGHER VOLATILITY = STRONGER TENDENCY TO CHANGE TO VAPOR = HIGHER SVP SVP METHOXYFLURANE: 23MMHG SEVOFLURANE: 160MMHG* ENFLURANE: 175MMHG ISOFLURANE: 238MMHG* HALOTHANE: 243MMHG DESFLURANE: 660MMHG* SVP AND TEMPERATURE CHANGES HEAT INCREASES SVP MORE MOLECULES ENTER GAS PHASE LESS MOLECULES “RE-ENTER” LIQUID PHASE COOLING DECREASES SVP LESS MOLECULES ENTER GAS PHASE MORE MOLECULES “RE-ENTER” LIQUID PHASE  CARRIER GAS (N2O AND O 2) PASSING OF CARRIER GAS OVER THE LIQUID DECREASES SVP HEAT IS NEEDED CONTINUOUSLY TO VAPORIZE ANESTHETIC AGENTS AND MAINTAIN CONSTANT SVP WHEN PRACTITIONER TURNS ON VAPORIZER, CARRIER GAS ENTER THE VAPORIZER TO “PICK UP” AND DELIVER VAA TO PATIENT SVP DECREASES THE LIQUID AGENT (E.G. ISOFLURANE) GENERATES MORE VAPOR AS AN “INHERENT ATTEMPT” TO KEEP SVP CONSTANT  HEAT IS LOSTDECREASED VAPORIZER OUTPUT TEMPERATURE COMPENSATION HEAT MUST BE SUPPLIED TO THE LIQUID ANESTHETIC INSIDE VAPORIZER TO MAINTAIN CONSTANT TEMPERATURE  CONSTANT SVP VAPORIZER CLASSIFICATION A. METHOD OF REGULATING OUTPUT CONCENTRATION 1. CONCENTRATION CALIBRATED (VARIABLE-BYPASS) 2. MEASURED FLOW (COPPER KETTLE) B. METHOD OF VAPORIZATION 1. FLOW OVER 2. BUBBLE THROUGH 3. INJECTION VAPORIZER CLASSIFICATION (CONT. C. ’) TEMPERATURE COMPENSATION 1. THERMO-COMPENSATION 2. SUPPLIED HEAT D. SPECIFICITY 1. AGENT SPECIFIC 2. MULTIPLE AGENT E. RESISTANCE 1. PLENUM- USED OUTSIDE BREATHING CIRCUIT (MOST COMMON) 2. LOW RESISTANCE- USED IN AUSTERE SITUATIONS THEY ARE IN-CIRCUIT TYPES OF VAPORIZERS HISTORIC (IN CIRCUIT) COPPER KETTLE VERNITROL MODERN (OUT OF CIRCUIT) OHMEDA TEC 4, 5, 7, ALADIN DRAGER VAPOR 19.1, VAPOR 2000 AND 3000 VAPORIZER MODELS AND FEATURES Classification Tec 4, 5, 7, SevoTec, and Aladin Tec 6 (Desflurane) (Aisys, Avance); Vapor 19, Vapor 2000 & 3000 Splitting ratio (carrier gas flow) Variable-bypass (vaporizer Dual circuit (carrier gas is not determines carrier gas split) split) Method of vaporization Flow-over (including the Aladin Gas/vapor blender (heat produces for desflurane, which does not vapor, which is injected into fresh require added heat like the Tec 6) gas flow) Temperature compensation Automatic temperature Electrically heated to a constant compensation mechanism temperature (39ºC; thermostatically controlled) Calibration Calibrated, agent-specific Calibrated, agent-specific Position Out of circuit Out of circuit Capacity Tec 4: 125 mL 390 mL Tec 5: 300 mL Vapor 19: 200 mL Aladin: 250 mL Method of regulating output concentration CONCENTRATION CALIBRATED (VARIABLE BYPASS) TOTAL CARRIER GAS FLOW AUTOMATICALLY DIVIDED INTO TWO PATHS ONE PATH FLOWING THROUGH VAPOR ABOVE LIQUID ANESTHETIC THE OTHER BYPASSING THE VAPOR CHAMBER. THE TWO FLOWS MEET AND MIX AT THE OUTFLOW TRACT. THE CONCENTRATION OF THE ANESTHETIC DETERMINED BY THE FLOW RATIO Examples are: Tec 3, 4, and 5 Vaporizers- Most common CONCENTRATION CALIBRATED (VARIABLE BYPASS) THE VAPORIZING CHAMBER INCORPORATES A NETWORK OF INTERNAL CHANNELS AND WICKS WHICH ENSURES THAT THE GAS EMERGING FROM THE CHAMBER IS FULLY SATURATED WITH ANESTHETIC VAPOR. THE CONCENTRATION OF THE ANESTHETIC AGENT IN THIS GAS IS THEREFORE KNOWN (FROM ITS SATURATED VAPOR PRESSURE) SO, WHEN THIS GAS IS MIXED WITH THE ANESTHETIC-FREE BYPASS GAS, THE CONCENTRATION OF ANESTHETIC IN THE GAS LEAVING THE VAPORIZER IS ALSO KNOWN. CONCENTRATION CALIBRATED (VARIABLE BYPASS) CONT.’ THE PROPORTION OF THE TOTAL GAS FLOW PASSING THROUGH THE VAPORIZING CHAMBER IS CONTROLLED BY A DIAL WHICH ACCURATELY INDICATES THE CONCENTRATION OF THE ANESTHETIC DELIVERED BY THE VAPORIZER IF THE DIAL OF A HALOTHANE VAPORIZER IS TURNED TO 2%, MORE CARRIER GAS GOES INTO THE VAPORIZER CHAMBER THAN IF THE DIAL IS SET AT 1% CHANGES IN TEMPERATURE COMPENSATION FOR THE EFFECTS OF CHANGES IN TEMPERATURE ON THE SVP (SATURATED VAPOR PRESSURE) OF THE ANESTHETIC MAY BE ACHIEVED IN A NUMBER OF WAYS: MINIMIZE TEMPERATURE FLUCTUATIONS BY HEAVY COPPER CONSTRUCTION (OLDER “COPPER KETTLE” VAPORIZERS) OR BRONZE, STAINLESS STEEL, AND ALUMINUM (NEWER VAPORIZERS) WHICH ACT AS HEAT SINK. COMPENSATE FOR TEMPERATURE CHANGES BY A VALVE THAT VARIES THE PROPORTION OF THE GAS THAT FLOWS THROUGH THE VAPORIZING CHAMBER Method of vaporization FLOW OVER CARRIER GAS FLOWS OVER LIQUID PICKING UP VAPOR. EFFICIENCY IMPROVED BY INCREASING AREA THAT CARRIER GAS FLOWS OVER GAS-LIQUID INTERFACE. IE. BAFFLES OR WICKS Method of regulating output concentration MEASURED FLOW (COPPER KETTLE & VERNITROL) ALSO KNOWN AS BUBBLE THROUGH OR VERNITROL. FLOW METER-MEASURED. MANUALLY CALCULATED BYPASSED CARRIER FLOW. TEMPERATURE COMPENSATED BY CONSTRUCTION MATERIALS WITH HIGH SPECIFIC HEAT AND THERMAL CONDUCTIVITY TO OFFSET COOLING FROM VAPORIZATION INDUCED HEAT LOSS. IE. COPPER AMOUNT OF CARRIER GAS (CG) O2 BUBBLED THROUGH IS DETERMINED BY A DEDICATED THORPE TUBE FLOWMETER A VALVE SEPARATES THE VAPORIZER CIRCUIT FROM THE STANDARD O2 & N2O FLOWMETERS Method of vaporization BUBBLE THROUGH CARRIER GAS IS BROKEN INTO SMALL BUBBLES USUALLY BY A MESH SCREEN AND BUBBLED THROUGH THE LIQUID ANESTHETIC (COPPER KETTLE, VERNITROL) VERNITROL BASED ON COPPER KETTLE COPPER KETTLE MATH VO: VAPOR OUTPUT (ML/MIN) CG: CARRIER GAS FLOW (ML/MIN) VP: VAPOR PRESSURE (MMHG) BP: BAROMETRIC PRESSURE (760MMHG) VAA%: VOLATILE ANESTHETIC AGENT CONCENTRATION VO = CG X VP VO = TOTAL GAS FLOW BP – VP VAA% EXAMPLES HALOTHANE: VP 243 MMHG CG: 100 ML/MIN VO = (100 ML/MIN)(243ML/MIN) = 24300 = 47ML/MIN (760MMHG – 243MMHG) 517 IF 1% OF HALOTHANE IS DESIRED: 47ML/MIN = 4700ML/MIN TOTAL GAS FLOW NEEDED 0.01 HALOTHANE IF 100ML/MIN OF O2 ENTERS KETTLE, 147ML OF GAS WILL EXIT (100ML OF O2 PICKED UP 47ML OF HALOTHANE) % HALOTHANE EXITING KETTLE IS 32% (243/760=0.32) AT 1 ATM IF ONLY 1% HALOTHANE NEEDED FOR ANESTHESIA, THE 32% NEEDS TO BE DILUTED WITH 4553ML/MIN 4700ML/MIN – 147ML/MIN = 4553ML/MIN MORE MATH ENFLURANE: VP 175 MMHG CG: 100 ML/MIN VO = (100 ML/MIN)(175ML/MIN) = 17500 = 30ML/MIN (760MMHG – 175MMHG) 585 IF 1% OF ENFLURANE IS DESIRED: 30ML/MIN = 3000ML/MIN TOTAL GAS FLOW NEEDED 0.01 3000ML/MIN-130ML/MIN=2870ML/MIN VAPOR 19.N VAPORIZER An annular valve constructed of dissimilar metals increases flow through the bypass when temperature increases (automatically done by vaporizer)  Basic Concentration calibrated, flow over, thermocompensation, agent specific, plenum vaporizers Drager Datex-Ohmeda Vapor 19.n Tec 5 VAPOR 19.N THE FRESH-GAS STREAM IS SPLIT INTO THE DOSAGE PATH AND BYPASS PATH THE STREAM THROUGH THE DOSAGE PATH IS DIRECTLY CONTROLLED BY THE CONTROL DIAL (CONTROL CONE) THE STREAM THROUGH THE BYPASS IS CONTROLLED BY A TEMPERATURE COMPENSATING BYPASS VALVE THE GAS FLOW IS LAMINAR OVER A WIDE FLOW RANGE ADDITIONAL COMPONENTS COMPENSATE BACK PRESSURE FLUCTUATIONS FROM THE BREATHING CIRCUIT IF THE DIAL OF A HALOTHANE VAPORIZER IS TURNED TO 2%, MORE CARRIER GAS GOES INTO THE VAPORIZER CHAMBER THAN IF THE DIAL IS SET AT 1% Method of vaporization INJECTION LIQUID ANESTHETIC OR PURE VAPOR IS INJECTED INTO VOLUME OF GAS. IF BOTH THE VOLUME OF CARRIER GAS AND ANESTHETIC VOLUME ARE KNOWN, CONTROL OF VAPOR CONCENTRATION CAN BE CALCULATED. GAS/VAPOR BLENDER (HEAT PRODUCES VAPOR, WHICH IS INJECTED INTO FRESH GAS FLOW) DUAL CIRCUIT (CARRIER GAS IS NOT SPLIT) ELECTRICALLY HEATED TO A CONSTANT TEMP (DATEX-OHMEDA TEC 6) Temperature compensation SUPPLIED HEAT MAINTAINS A CONSTANT TEMPERATURE BY ELECTRIC HEATER. EXAMPLE TEC 6 DESFLURANE LowVAPORIZER boiling point 22.8C causes unpredictable output Supplied Heat (Must be connected to electrical outlet): Warms liquid Desflurane to 39C to achieve a pressure of 1,500 mmHg Controls gas output by variable resistance via a differential pressure transducer TEC 6 DESIGNED FOR THE DELIVERY OF DESFLURANE ELECTRONIC VAPORIZER WHICH HEATS DESFLURANE TO MAINTAIN CONSTANT TEMPERATURE AND VAPOR PRESSURE FOR CONSISTENT OUTPUT IT HAS AN LED DISPLAY WHICH INDICATES VAPORIZER STATUS - NO OUTPUT, LOW AGENT, WARM-UP, OPERATIONAL AND ALARM BATTERY LOW FEATURES SEVERAL INTRINSIC VAPORIZER MONITORS AND ALARMS THAT CONSTANTLY MONITOR VAPORIZER STATUS.  TEC 6 -The major problem presented by Desflurane is that it is extremely volatile: at 22.8C (boiling point) is only slightly above normal room temperature, which precludes the use of a normal variable-bypass vaporizer. -The Tec 6 vaporizer avoids this problem by heating the Desflurane liquid to above its boiling point in a sealed chamber and mixing pure Desflurane gas with the carrier gas. TEC 6 IF POWER IS LOST VAPORIZER WILL NOT FUNCTION AND WILL NOT DELIVER AGENT TO THE PATIENT THIS IS NOT A PROBLEM WITH THE NEWER ALADIN VAPORIZERS THAT DO NOT REQUIRE HEAT FOR DESFLURANE Specificity MULTIPLE AGENT RARELY IN USE AND NOT ADVISED. MAY BE USED WITH MULTIPLE AGENTS MUST BE LABELED WITH AGENT AGENT CONTAINED WITHIN. Resistance LOW RESISTANCE LOW RESISTANCE ALLOWS PLACING VAPORIZER WITHIN THE BREATHING SYSTEM. VAPORIZATION ACCOMPLISHED BY VENTILATORY GAS FLOWS. THE OMV IS PARTICULARLY VERSATILE, SINCE THE SAME VAPORIZER CAN BE USED TO VAPORIZE A NUMBER OF AGENTS WITH ONLY THE DIAL SCALE BEING CHANGED Oxford Miniature Vaporizer WRONG AGENT IT CAN BE EXTREMELY DANGEROUS TO DELIVER ANESTHETICS FROM VAPORIZERS FOR WHICH THEY WERE NOT DESIGNED. A VAPORIZER INTENDED FOR USE WITH METHOXYFLURANE (SVP=23) FILLED WITH ISOFLURANE (SVP=239) AND WITH THE DIAL SET TO 1% WOULD IN FACT BE PRODUCING ABOUT 15 % ISOFLURANE. WHAT ABOUT FILLING AN HALOTHANE VAPORIZER WITH ETHRANE???? (LOWER [] RESULTS) WRONG AGENT F’=DELIVERED CONCENTRATION; F=SETTING IN VAPORIZER; P’V=VAPOR PRESSURE OF VAPORIZER; PV=VAPOR PRESSURE OF AGENT IN VAPORIZER; PB=BAROMETRIC PRESSURE. THIS FORMULA IS USED TO CALCULATE WHAT HAPPENS WHEN YOU HAVE THE WRONG AGENT AND SET THE DIAL IN THE VAPORIZER. VAPO RI ZER TYPES GE Aladin Vaporizing System Operation 01 02 03 04 GE Aladin Vaporizing System Monitoring and Gas Flow Control Filling and Removing System Control Bottles Combines variable bypass and Monitors and controls gas and Controlled through N2O, O2, and Involves specific steps to prevent measured flow principles. vapor flow to ensure minimum air flowmeters. spillage. oxygen concentration. Anesthetic agents have unique Correct volume percent output Operation involves dividing gas cassettes with agent-specific fill Cassette identifies itself to the maintained by the system. flow into two routes based on systems. workstation through signature concentration setting. magnets. 14 / Advanced Concepts in Anesthesia Vaporization Dräger Vaporizer Features and Operation 01 02 Dräger Vaporizer Features Dräger Vaporizer Operation Automatic temperature compensation Operation involves splitting gas flow for consistent output for precise vapor concentration Incorporates a thermometer for monitoring liquid agent temperature Temperature-sensitive valve adjusts gas flow for stability Grid lines on control dial aid in temperature compensation 15 / Advanced Concepts in Anesthesia Vaporization Penlon Sigma Alpha Vaporizer Functionality 01 02 03 04 05 Controlled Flow of Constant Vapor Proportional Valve Self-Check and Mechanical Pump Vaporized Agent Pressure Control Calibration and Pressure Maintenance Monitoring Ensures precise delivery of Heated chamber maintains Microprocessor-controlled Performs self-check during Transfers agent using anesthetic agent consistent vapor pressure valve start-up mechanical pump Integrates with fresh gas Ensures reliable anesthetic Adjusts flow based on Calibrates system for Monitors reservoir pressure flow delivery requirements accurate operation for consistency 16 / Advanced Concepts in Anesthesia Vaporization VAPORIZER HAZARDS INHALATION OF FOREIGN SUBSTANCES Causes include: *Absorbent dust *Residual ethylene oxide or glycol *Contaminants in compressed air *Breathing system components, and foreign bodies Preventing or detecting foreign substances: *Assessment of patient and machine during set up and use *Airway obstruction will cause high airway pressure alarms to sound *Use of filter on breathing Circuit *Never release bag pressure at Y-connect (use APL valve)  OVERDOSING Overdose causes: *Tipping of vaporizer (more liquid will go into bypass area) *Vaporizer inadvertently turned on or never turned off from previous use *Overfilled vaporizer *Simultaneous use of vaporizers on older machines without interlock system (if center vaporizer is removed, place remaining 2 together) *Incorrect calculations with measured-flow vaporizers (Copper Kettle) *N2O flowmeter bobbin or float stuck at top of Thorpe tube *Pumping effect due to inspiratory positive pressure from manual or assisted ventilation or use of O2 flush valve transmitted back to vaporizer. Seen with low flows.  INADEQUATE DOSE Inadequate dose causes: Light anesthesia is not always as serious, but may be deleterious *O2 flowmeter bobbin or float stuck at top of Thorpe tube *Disconnect that allows air to be entrained into breathing system *Repeatedly using flush valve diluting concentration *Leak in bellows *Empty vaporizer or leak in vaporizer *Incorrect calculations with measured-flow vaporizers *Pressurizing effect- due to inspiratory positive pressure from manual or assisted ventilation or use of O2 flush valve transmitted back to vaporizer. Seen with high flows. QUESTIONS??