1.Guidance-Presented By-Dr.Sadhana Jain Prof. & Head Dept. of Anaesthesiology,Dr. Deepak Kumar Post Graduate student Dept. of AnaesthesiologyS.P. Medical College , Bikaner1

2. ANAESTHESIA MACHINE Anaesthesia machine is a device which delivers precisely known but variable gas mixture, including anaesthetizing and life sustaining gases ANAESTHESIA MACHINE- 2 types 1. Intermittent gas flow type 2. Continuous gas flow type 3. Intermittent gas flow type 1. 2. They provide oxygen and nitrous oxide. They operate on demand. Gas flow are drawn by inhalation. They are useful for short surgical procedures . Example Walton V machine Modified Walton V machine(Lucy Baldwins apparatus) 3 4. 3. Entonox apparatus :Intermittent gas flow machine by Rovenstein. It has premixed cylinder of oxygen (50%) with nitrous oxide (50%). - Cylinder has body of French blue with top white with pin index of 7. - Pressure regulator. - Pressure gauge (2000 psi). - Demand valve. - Key to open the cylinder. - Circuit provided with facemask, expiratory valve, corrugated tube & metal hand piece to hold mask.4 5. - Oxygen & nitrous oxide mixture available in gas form dueto Poynting effect. (At 2000 psi pressure & at room temperature, oxygen has solvent action, keeps nitrous oxide in gaseous form) - The mixture separates into component parts, at -7 degree celsius known as pseudocritical temperature, carries risk of hypoxia due to nitrous oxide . - This is prevented by: proper storing, avoiding excessive cooling rewarming of cylinder, shaking , inverting several times before use. 5 6. - Used very effectively as analgesic for : . Dressing of surgical wounds. . Dressing of burns. . Labour analgesia. . Dentistry. . Pain relief for trauma pts. . Post-operative pain relief . In ophthalmological examination. . During cardiac catheterization.6 7. - Other intermittent gas flow machines : 1) EMOTRIL E.M.O. apparatus with trilene. Grey in colour. Draw-over giving air+trilene (0.3 to 0.5 %). 2) TECOTA Temperature compensated trilene apparatus giving air+trilene . 3) CYPRANE INHALER - Giving air+ methoxyflurane(0.35 %) for labour analgesia. 4) CARDIFF INHALER - Giving air+ methoxyflurane(0.35 %) for labour analgesia. ( inhaled during painful uterine contractions in first stage of delivery.7 8. Continuous gas flow type-Gas flows both during inspiration and expiration. Egs : Boyle Machine Forregar Dragger 9. History INVENTOR ? Henry EdmundGaskin Boyle 1917 Modified machine manufactured by James Tayloe Gwathmy 10. ORIGINAL BOYLES MACHINE Sight-feed water bottle and controlsmounted on a vertical rod 4 N2O cylinders Reducing valves with spirit lamps 1 O2 cylinder Rebreathing bag Face piece/mask 11. MODIFICATIONS 1920 : Addition of ether bottle 1926 : Addition of chloroform bottle 1927 : Back bar added 1930 : Addition of plungers and cowls in etherand chloroform bottles 1933 : Dry bobbin flow meters replaced water sight feed bottles 1937 : Rotameter displaced dry bobbin flowmeters 1979 : Standards for anaesthesia machines 12. MODELS AVAILABLE IN INDIA Porta Boyle King Porta Boyle Boyle Cadet Boyle F Boyle major Boyle mark III (Boyle Basic) Boyle mark IIIS Boyle mark IV 13. the traditional pneumatic anesthesia machine has evolved into a complex electrical, mechanical and pneumatic multi component workstation 14. Functions of a WORKSTATION Safe provision, selection and delivery of anesthetics Provision of back up supplies of gases Respiratory support Monitoring of machine function Monitoring of patient Record Keeping Anesthetic Gas Scavenging System (AGSS) Suction regulator Supplemental oxygen Work surface and storage facility for everyday items Electricity sockets 15. SYSTEM COMPONENTS ELECTRICAL COMPONENTSPNEUMATIC SYSTEM 16. Electrical Components Master Switch: Activates both electrical and pneumatic function Standby mode: Quicker power up 17. Electrical Components Power failure indicator: Visual or Audible indicator to alert provider of powerfailure. 18. Reserve power: Electricity is crucial Backup necessary Back up with Single power source UPS may be added Amount of charge left is displayed 19. Electrical Components Electrical outlets Convenience electrical outlets on the back of theanesthesia machine. These should be used only for anesthesia monitors and not for general operating room use. Circuit breakers to protect from overload 20. Data communication ports : Communication between anaesthesia machine, monitors and data management system.View Figure 21. PNEUMATIC SYSTEM 22. 100 kPa = 1000 mbar = 760 mm Hg = 1030 cm H2O = 14.7 psi = 1 atm 1 psi = 6.8 kpa Psig = pounds per square inch gauge 23. Pneumatic systemHigh Pressure systemIntermediate Pressure systemLow pressure system 24. O2 = 2000 psig N2O = 750 psigCylinder = 45- 50 psig Pipeline= 50- 60 psigjust above atmospheric pressure and variable (5-8 psig) 25. BRIEF NOTE ON CYLINDERS Components: Body Valve Port, stem Handle Pressure relief device Conical depression Pin index safety system 26. BODYAlloy of molybdenum and steel MRI ALUMINIUM VALVEFilled and discharge through valve Port : Point of exit Stem : stem against seat arrangement to close valve HANDLEbody 27. CONICAL DEPRESSIONReceives retaining screw of the yoke PRESSURE RELIEF DEVICEVenting of contents at dangerously high pressures TYPES : Rupture disc copper Fusible Plug (Woods alloy) bismuth, lead tin, Cadmium (Melts at 150-170 deg F) Combination of both Pressure relief valve (spring loaded) 28. SIZE OF CYLINDERS Cylinder classified using a letter code A type cylinders are smallest However AA (smaller than A) also available. SIZE D & E is the cylinder most commonly used 29. TYPICAL MEDICAL GAS CYLINDRES, VOLUMES, WEIGHT cylinde r sizeCylinder Dimensions (O.D. Length in Inches)wt .(lb)A B3X70.233 1/2 x 135D4 1/2 x 1711E41/4 x 26M7EMPTYoxygn (litres)NITROUSO XIDE76Air CO2 (litres) (litre s)189(litres)370200375940400146251590 6601590x 436328507570 34507570G8 1/2 x 519750501230 013800H91/4 X 511196550690094015800 30. COLOUR OF CYLINDER GASUSAINTERNATIONALoxygenGreenWhite Shoulder& Black Body GrayCarbon dioxide Gray Nitrous oxide heliumBlueBlueBrownBrownNitrogenBlackBlackAirYellowGray Body ,Shoulder black/white quartered 31. CONTENT AND PRESUREFIG:A nonliquefied gas such as oxygen will show a steady decline in pressure until the cylinder is evacuated. Each cylinder, however, will show a steady decline in weight as gas is discharged. 32. CONTENTS AND PRESSUREFIG:The relationship between cylinder weight, pressure, and contents. A gas stored partially in liquid form, such as nitrous oxide, will show a constant pressure (assuming constant temperature) until all the liquid has evaporated, at which time the pressure will drop in direct proportion to the rate at which gas is withdrawn. 33. Cylinder marking1.Name of manufacturer and name of institute 2.Specific number 3.Name of the gas 4.Year of testing and name of the test like BT-bending test 5.Weight in kg 6.Capacity in liters Name of tests1.BT-Bending test 2.Tensile test 3.Impact or flattening test 4.Pressure or Hydraulic test(Every 5 year)35 34. Critical Temperature is the temperatureabove which any gas cannot be liquefied no matter how much pressure is applied ( O2=-119 C, N2O= 36.5 C) Critical pressure is the minimum pressure that is required to liquefy a gas at critical temperature. Service pressure is the maximum pressure to which cylinder may be filled at 21.1 C Filling ratio (for liquefied gases) is the percent ratio of the weight of the gas in the cylinder to the weight of water a cylinder can hold at 60 F. (N2O = o.68 in tropical, 0.75 in temperate) 35. Components of pressure systems 36. High Pressure System HIGH, VARIABLELOW, CONSTANT Components Hanger yoke assembly Cylinder Pressure Indicator Pressure Regulators 37. HANGER YOKE Orients and supports the cylinder Gas tight seal, unidirectional flow 38. BODY BODY Threaded into frame of machine Supports cylinder Hinged Swinging gate Swinging gate 39. RETAINING SCREW: Threaded into the distal endof yoke Tightening the screw gas tight seal Conical point fits into conical depression on cylinder NIPPLE: Projects from yoke and fits into cylinder port Entry of gasNIPPLERETAINING SCREW 40. INDEX PINS Component of pin indexsafety system 4mm in diameter and 6mm long (except pin 7 which is slightly thicker) . Pinhole are 4.8mm indiameter . Diameter of valve outlet is 7mm Fit into the correspondingholes on the cylinder Holes are on the circumference of a circle of 9/16th inch radius centered on the port of a cylinder 41. 1, 3 1, 4 1, 5 1, 6 2, 4 2, 5 2, 6 3, 5 3, 6 4, 6 7Ethylene Nitrogen Air CO2 or O2 (CO2 >7%) Helium & O2 (He