1. The Anaesthesia Machine
4th year MB ChB tutorial

2. Anaesthesia Delivery Systems
Draw-over Machines
Uses the atmospheric supply of Oxygen (21%)
Oxygen source to augment atmospheric O2 if required
Rural areas
Boyles Machine
Requires a supply of oxygen and other piped medical gases (Air, Nitrous oxide) under pressure
Modern machines
Available in most hospitals

3. The Boyle’s Machine Purpose of the machine
Delivery of gases to the patient
Anaesthetic gases (volatiles, inhalationals etc)
Medical gases: air, O2 and N20
Ability to ventilate patient
Provide IPPV (Intermittent Positive Pressure Ventilation)

4. 5 Basic parts to the machine
Supply of gases under pressure
Piped medical gas supply from central depot
Cylinders on machine
Means of controlling / measuring gas flow
Flowmeters / rotameters
Vaporisers
Breathing System
Circle systems
Open systems: Magill, Bain and Ayre’s T-piece
Means to ventilate patient
Reservoir bag for manual ventilation
Ventilator for IPPV

5. THE MACHINE Many different types ranging from ...

6. Simple

7. Most modern
Dräger Zeus

8. The Blease Machine
@ GSH

9. SUPPLY OF GASES

10. O2 Oxygen
Reticulated supply

11. Piped Medical Gases

12. Liquid Oxygen Tank

13. Gas outlets in theatre

14. Oxygen on machine
Reticulated supply
Cylinder
O2 concentrator

15. N2O Nitrous oxide
Nitrous Oxide Cylinders

16. FLOWMETERS

17. Rotameters
SA standard has O2 on the Right. (UK and other commonwealth countries have it on the Left)

18. VAPORISERS

19. Vaporisers

20. BREATHING SYSTEMS

21. Circle system

22. Soda-lime canister

23. Soda-lime The main components of soda-lime
Calcium hydroxide (75%)
Water (20%)
Sodium hydroxide
Potassium hydroxide
The patient's expired gases which contain carbon dioxide, are passed through a circle absorber filled with soda-lime granules
Medical grade soda-lime has indicators which change colour when the soda-lime loses its carbon dioxide absorbing capacity

24. Magill Open System

25. Ayre’s T-piece (Jackson-Rees modification)

26. Ayre’s T-piece

27. Reservoir bag Converts a continuous flow to an intermittent flow
Manual ventilation
PEEP
Watch patient’s own ventilation
Check the circuit for leaks

28. Self-inflating resuscitator
In case the machine fails!!

29. VENTILATION

30. Ventilator

31. Other devices on anaesthetic machine
Oxygen Flush
Oxygen analyser
Oxygen supply failure alarm
“Pop - off” valve
Non - return valve

32. SUCTION

33. Suction apparatus Check function
- 50 kPa negative pressure if occluded
Check presence of suction nozzle (Yankauer) and catheters

34. ANCILLARY EQUIPMENT

35. Airway Trolley IMALES Introducer Mask, Magills forceps
Airways (Guedel)
Laryngoscopes, LMA (alternative airway)
Endotracheal tubes (ETT)
Suction

36. Defibrillator

37. MONITORING APPARATUS

38. Monitors of machine-patient interface
Oxygen analyser - FIO2
Ventilatory parameters
Tidal volume - VT, RR, I : E ratio, MV
Airway pressure - PAW
Capnograph / disconnect alarm - PETCO2
Agent monitor for anaesthetic gases
FIAA
FETAA (≈ MAC)

39. Monitors of the Patient
ECG
NIBP
Capnograph
Pulse Oximeter
Temperature probe
Nerve stimulator
Invasive
Arterial line for BP
CVP monitoring
Urinary catheter
Pulmonary artery catheter – rarely used

40. ECG Monitor

41. NIBP: Non-invasive blood pressure

42. Capnograph

43. Pulse oximeter

44. Peripheral nerve stimulator

45. Central venous access and pressure line (CVP)

46. Pulmonary artery catheter: PAC or Swan-Ganz catheter

47. PAC

48. PAC