There are several types of Mapleson breathing systems classified based on the position of the reservoir bag. Mapleson A has an afferent reservoir with the bag attached to the fresh gas inlet. Mapleson D has an efferent reservoir with the bag attached to the patient outlet. Both systems allow for spontaneous or controlled ventilation but Mapleson D is more efficient due to continuous mixing of fresh gas and exhaled gases. The systems are tested for leaks and proper functioning using various occlusion and pressurization techniques.

1. MAPLESON BREATHING SYSTEMS MODERATOR : DR RANJAN R K PRESENTER : DR NIKHIL M P

2. History In 1954 Mapleson described and analyzed Five different anaesthetic breathing systems & referred as Mapleson A – E. Bain circuit in 1972 by Bain & Spoeral

3. In 1975 Willis et al described F system & added to above. In 1976 – Lack circuit .

4. CLASSIFICATION

5. MAPLESON A Classic & Lack’s modification MAPLESON B MAPLESON C MAPLESON D Classic form & Bain’s modification MAPLESON E MAPLESON F

6. BASED ON THE RESERVOIR BAG POSITION Afferent reservoir system eg:Mapleson A,B,C & Lack’s Afferent limb:delivers FGF from machine to patient end

7. Efferent reservoir system eg:Mapleson D,E,F & Bain’s Efferent limb:carries expired gas from patient & vents it to the atmosphere through expiratory valve

8. Breathing systems Bidirectional flow & without carbondioxide absorption & Semiclosed system MAPLESON SYSTEMS

9. Mapleson’s assumptions Gases move enblock fresh gas,dead space gas,alveolar gas 2. Reservoir bag continues to fill,without offering any resistance till it is full

10. 3. Expiratory valve opens as soon as reservoir bag is full & the pressure inside the system goes above atmospheric pressure 4. Valve remain opens throughout the expiratory phase and closes at the start of next inspiration MAPLESON’S ASSUMPTIONS CONTD.

11. Afferent reservoir systems

12. MAPLESON A SYSTEM

13. Magill system FGF enters the system near machine end A corrugated tubing connects the reservoir bag to APL valve of the system MAPLESON A

14. MAPLESON A

15. Lack’s modification Expiratory limb –from patient end to APL valve at the machine end of the system 2 forms dual tube (parallel) tube-within-a-tube(coaxial )

16. LACK’S MODIFICATION

17. Functional analysis

18. Spontaneous breathing

19. MAPLESON A- spontaneous respiration

20. a. During inspiration,FG from the machine and reservoir bag flows to the patient,RB collapses b. During expiration,FG continues to flow.expired gas (dead space gas & alveolar gas) pushes the FG into RB and collects inside the corrugated tube MAPLESON A – SPONT. CONTD.

21. c. Expiratory valve opens and alveolar gas is vented into atmosphere d. During Expiratory pause,alveolar gas that had come in contact with the corrugated tube is also vented depending on FGF. MAPLESON A – SPONT. CONTD.

22. System is filled with only FG & dead space gas at the start of next inspiration when FGF =Minute ventilation Alveolar gas+dead space gas+some of FG also escapes if FGF>minute ventilation Some alveolar gas +dead space gas will remain if FGF < minute ventilation MAPLESON A – SPONT. CONTD.

23. MAPLESON A SPONTANEOUS

24. Controlled ventilation

25. MAPLESON A- controlled ventilation

26. a . During inspiration,patient gets ventilated with FG & part of FG is vented through the valve. b. During expiration,FG flows into RB & expired gases flows back into corrugated tubing till system is full MAPLESON A- controlled ventilation contd.

27. c. During next inspiration alveolar gas is pushed back into alveoli followed by FG part of expired gas & part of FG escape through the valve when sufficient pressure is developed rebreathing inefficient for controlled ventilation MAPLESON A- controlled ventilation contd.

28. MAPLESON A - CONTROLLED

29. TESTS FOR MAPLESON A SYSTEMS

30. Tested for leaks by occluding the patient end of the system,closing the APL valve & pressurizing the system APL valve opens TESTS FOR MAPLESON A CONTD.

31. To attach a tracheal tube to the inner tubing at the patient end of the system To occlude both limbs at the patient connection with APL valve open TESTS FOR COAXIAL LACKS SYSTEM

32. FGF Requirement Spontaneous : equal to minute ventilation Controlled :very high & difficult to predict.

33. MAPLESON B SYSTEM

34. MAPLESON C SYSTEM

35. MAPLESON A,B,C

36. Efferent reservoir system

37. They have a 6mm d. tube as afferent limb and carries FGF from machine end to patient end . Reservoir bag is attached to efferent limb which is a wide bore corrugated tube EFFERENT RESERVOIR SYSTEM CONTD .

38. APL valve is placed near the reservoir bag In Bain’s modification afferent & efferent limbs are coaxially placed Inner tube – 6mm Outer tube – 22 mm Length- 180 cms EFFERENT RESERVOIR SYSTEM CONTD .

39. Mapleson D system

40. MAPLESON D

41. BAIN’S CIRCUIT

42. Functional analysis

43. Spontaneous respiration

44. MAPLESON D - Spontaneous respiration

45. a.During inspiration,FG from the machine,RB & corrugated tube flow to the patient b.During expiration,FGF to the system at the patient end & expired gas gets continuously mixed with FG as it flows back into corrugated tube & reservoir bag MAPLESON D CONTD .

46. c.Once the system is full, the excess gas is vented to the atmosphere through the APL valve during expiratory pause FG continues to flow & fill the proximal portion of corrugated tube while mixed gas is vented through the valve MAPLESON D CONTD .

47. d . During next inspiration,patient breaths FG & mixed gas. MAPLESON D CONTD.

48. Controlled ventilation

49. MAPLESON D-controlled ventilation

50. a.During inspiration the patient gets ventilated with FGF from the machine,corrugated tube & RB. b.During expiration the expired gas gets mixed with the fresh gas that is flowing into the system at patient end During expiratory pause the FG continues to enter the system and pushes the mixed gas towards RB. MAPLESON D CONTROLLED CONTD .

51. c. When next ventilation is initiated patient gets ventilated with the gas in the corrugated tube. As the pressure in the system increases APL valve opens and contents of RB are released into the atmosphere. MAPLESON D CONTROLLED CONTD .

52. BAIN’S CONTROLLED.

53. FGF Requirement Spontaneous : 1.5 to 3 times minute ventilation ( 100 to 300 ml/kg/min) Controlled : 1 to 2 times minute ventilation

54. MINUTE VENTILATION F R E S H G A S F L O W PaCO 2 Almost same PaCO2- for FGF from 100 to 240ml/kg/min

55. Tests for Mapleson D

56. By occluding the patient end & closing the APL valve,pressurizing the system Open the APL valve Bag deflates easily TESTS FOR MAPLESON D CONTD.

57. Occlude the inner tube at the patient end after setting a low flow oxygen If the inner tube is intact the flowmeter indicator will fall TESTS FOR BAINS SYSTEM

58. Pethick test Activate oxygen flush & observe the bag Venturi effect caused by high flow oxygen at the patient end will create a negative pressure at the outer tube Bag deflates TESTS FOR BAINS SYSTEM

59. Advantages Can be usedin controlled/spontaneous respiration Adults & Pediatrics Portable,Light weight Scavenging of exhaled gases

60. Hazards Accidental disconnection of inner tube from machine end. ‘ Double back’ itself & cause obstruction to FGF.

61. THANK YOU