- A breathing system connects a patient's airway to an anesthetic machine and creates an artificial atmosphere. It consists of a fresh gas entry port, connection to the patient's airway, reservoir bag or tubing, and expiratory port. - The Mapleson systems are types of breathing circuits classified by their design. Mapleson A uses a reservoir bag and has high rebreathing during controlled ventilation. Mapleson B and C shift the gas entry point but are still inefficient. The Bain circuit is a modified Mapleson D that reduces rebreathing using a coaxial tube design. - The T-piece or Mapleson F system is commonly used for children, consisting of a T-shaped connector,

1. RESERVOIR BAG Part-1
Dr Nisar Ahmed Arain
Assistant Professor
Anesthesia/Critical Care/ER

2. DEFINITION
-A Breathing system is defined as
an
assembly of components
which
connects the patients airway
to
the anesthetic machine
creating an artificial
atmosphere
from and into which the
patient
breathes.

3. This primarily consists of
-a) A fresh gas entry port/delivery tube through
which
gases are delivered from machine to the
systems
-b)Aport to connectit to patient’sairway
-c)A reservoir for gas ,in the form of bag or a
corrugated
tubing to meet the peek inspiratory flow
requirements
-d)An expiratory port/valve through which the
expired
gas is vented to the atmosphere
-e)A carbon dioxide absorber if total rebreathing is
to
be allowed and

4. REQUIREMENTS
OF A BREATHING SYSTEM
Essential
a)-The breathing system must deliver the
gases
from the machine to the alveoli in the
same
concentration as set and in the shortest
possible time
b)- Effectively eliminate carbon dioxide
c)- Have minimal apparatus dead space
and
d)- Have low resistance towards movement
of
gases.

5. What is Desirable
The desirable requirements
are
--a)-Economy of fresh gas
--b)-Conservation of heat
--c)-Adequate humidification of inspired gas
--d)-Light weight & convenient during use
--e)-Efficiency during spontaneous and
controlled ventilation
--f)-Adaptability for adults,
children
and mechanical ventilators
-g)-Provision to reduce theatre
pollution

6. OPEN NO BOUNDRY
AND NO DEAD
SPACE
OXYGEN
TUBING NEAR
PATIENT
SEMI OPEN PARTIAL
BOUNDRY
BETWEEN
AIRWAYAND
ATMOSPHERE
SCHIMMELBUCH
MASK
SEMI closed FULLY BOUNDED
.Prevents entry of
atmsph. Air but
vents excess fresh
gas
MAPLESON SYTEM
Closed No Venting Of Excess
G
as
Circle system at low
flows
Classification

7. NO SODA LIME SO
DA
LIME
Unidire
ct
ional
Non Breathing circle system Circle Syste
m
Bidirecti
onal
a)Afferent reservoir systems.
Mapleson A , B ,& C
b)Enclosed afferent reservoir
systems Miller’s
c)Efferent reservoir
systems Mapleson D
, E & F
Bain ‘s system
d)Combined
Systems
Humphery ADE
Waters Canist
er
-Many Configurations

8. Components
of a Breathing System
-Adjustable Pressure Limiting
Valve
-Reservoir Bag
-Tubing

9. -Adjustable Pressure Limiting Valve
-Spill valve, pop –off valve, expiratory valve
-Designed to vent gas during Positive Pressure
-Pressure of less than 0.1 kPa activates the
valve
when open.
Components:- 3 Ports
-Inlet, patient & exhaust port-later can be open to
atmosphere or connected to scavenging
system
-Lightweight disc sits on a knife edge seating
held in
place by a spring
-TENSIONin the spring andtherefore thevalve’s
opening pressure is controlled by the valve
dial

10. -Mechanism of Action
--One way , adjustable , spring loaded valve
allows gases to escape when pressure in the
breathing system exceeds the valve's
pressure
During spontaneous
ventilation
the patient generates a positive pressure
during expiration causing the valve to open
During positive pressure
ventilation
--A controlled leak is produced in the inspiration
by adjusting the valve dial, allowing
control of
the patient’s airwaypressure.

11. -Connector and adaptor
-A connector is a fitting device intended to join
together
two or more similar components .
-An Adaptor is a specialized connector that
establishes
functional continuity between otherwise disparate
or
incompatible components.
They can be used to
-a)-Extend the distance between patient & breathing
system esp. in head and neck surgeries.
-b)-Change the angle of connection between patient
and
breathing system.
-c)-Allow a more Flexible and Less kink able

13. RESERVOIR BAG
-Also known as Respiratory ,Breathing or sometimes
called
Rebreathing bag standard size is 2liters(but range from
0.5 to 6 (iters) .
-Made up of Rubber and Plastic ,ellipsoid in shape
following are the functions of Rebreathing bag
1- It allows gas to accumulate during exhalation & provides
gas for
next inspiration and permits rebreathing
2-It provides a means whereby ventilation may be assisted
or
controlled.
3-It can serve through visual and tactile observation as a
monitor
of spontaneous respiration.

14. -RESERVOIR BAG different Sizes

15. -TUBING
Corrugated or smooth
-Different lengths are available depending on system being
used
-Allows humidification of inspired air
-Parallel and coaxial arrangements available

16. Afferent
systems
-Mapleson A
-Mapleson B
-Mapleson C
Lack Modification
Efferent
sytems
-Mapleson D
-Mapleson E
-Mapleson F
-Mapleson systems

18. -Mapleson A system
-Corrugated rubber or plastic tubing
10-130 cm in length
-Reservoir Bag at Machine end
-APL valve at the patient end
-Tube volume > Tidal volume

19. Spontaneous breathing
The system is filled with fresh gas before connecting it
to the patient . When the patient inspires, the fresh gas
from the machine and the reservoir bag flows to the
patient , and as a result the reservoir bag collapses.
-Mapleson A : Functional Analysis

20. ---The expired gas , initial part of which is the
dead space gas , pushes the FG from the
corrugated tube into the reservoir bag and
collects inside the corrugated tube.
---Expiratory pause- Fresh gas washes the expired
gas of the reservoir ,filling it with fresh gas for
the next inspiration.

21. -Tofacilitate IPPV the expiratory valve has to
be
partly closed.
-During inspiration the patients gets
ventilated
with FG and part of the FG is vented
through
the valve after sufficient pressure has
developed to open the valve.
-Controlled Ventilation

22. - During expiration
---the FG from the machine flows into
the reservoir bag and all the expired
gas ( i.e. dead space and alveolar gas
flows back into the corrugated tube till
the system is full.

23. ---During the next inspiration the alveolar gas
is
pushed back into the alveoli followed by the
fresh gas. When sufficient pressure is
developed, part of the expired gas and part
of the FG escape through the valve.
---This leads to considerable rebreathing as
well
as excessive wastage of fresh gas . Hence
these system are inefficient for controlled
ventilation.

24. -Coaxial modification of Magill Mapleson A.
-1.5 m in length
-FGF through outside tube ( 30mm)
exhaled gases from inner tube.
-Inner tube wide in diameter (14 mm) to
reduce resistance to expiration(1.6 cm
H2O).
-Reservoir bag at machine end
-APL valve at machine end.
-Better for spontaneous ventilation.
-Mapleson A –Lack Modification

25. -This system functions like Mapleson A both
during spontaneous & controlled
ventilation.
-The only difference is that expired gas
instead
of getting vented through the valve near
the
patient ,is carried by an afferent tube
placed
coaxially and vented through the valve
placed
near the machine end. This facilitates easy
scavenging of expired gases.

26. -Function of Lack of modification

27. Mapleson B System
-- The FG inlet is near the patient, distal to the expiratory
valve
-- The expiratory valve open when pressure in the circuit
rises
and a mixture of retained fresh gas and alveolar gas is
inhaled
-- Rebreathing is avoided with fresh gas flow rates of
greater than
twice the minute ventilation for both spontaneous and
controlled ventilation

28. -Thiscircuit isalsoknown asWater’scircuit.
-It is similar in construction to the Mapleson B
but the main tube is shorter.
-A FGF equal to twice the to twice the minute
ventilation is required to prevent rebreathing.
Carbondioxide builds up slowly with this
circuit.
-Mapleson B &C : In order to reduce rebreathing
of alveolar gas FG entry was shifted to near
the patient.
-This allows a complete mixing of
FG and expired gas
-The end result is that these system are neither
efficient during spontaneous nor during
controlled ventilation.
Mapleson C system

30. -Introduced by Phillips Arye in 1937.
-Belongs to Mapleson E.
-Available as metallic and plastic made.
-Length –2 inches.
-Parts –inlet, outlet, side tube.
-Inlet size-10 mm, outlet size-10mm
metallic
& 15 mm plastic
AyresT-PIECE

31. ---Simple to use and Light weight .
---No dead space , no resistance.
---Specially for pediatric patients Less than 20 kgs.
---Expiratory limb is attached to the outlet of T piece.
---It should accommodate air space equal to 1/3rd
of TV.
---If too short –air dilution will occur in
spontaneously
breathing patients & patients become light.
---1 inch of expiratory tube can accommodate 2-3
ml
of gas.
-Gas Flows –2- 3 times MV
Advantages

32. -High flow rates are required.
-Loss of heat and humidity.
-Risk of accidental occlusion of
expiratory limb
-Risk of increased airway
pressure
and barotrauma to lungs.
Dis advantages

33. -It consists of fresh gas inlet nearer the patient
end , a corrugated rubber tubing one end
which is connected with expiratory valve and
then reservoir bag.
-It is mainly used for assisted or
controlled
ventilation
-During the controlled ventilation there is little
chance of rebreathing.
-The FGF which enters during expiratory pause
accumulates in the patient end is forced
during the inflation.
-Mapleson D System

34. ---In spontaneous breathing during inspiration the
patient will inhale the fresh gas & gas in
corrugated tube depending on FGF, TV, length
of expiratory pause & volume of corrugated
tube.
---Rebreathing can be minimized by increasing
FGF 2-3 times the MV.
---For an adult 15L/min FGF which seems
uneconomical is required.
---In some cases 250 ml/kg/minrequired to prevent
rebreqthing.

35. -Introduced by Bain & spoerel in 1972.
-It is a modification of Mapleson D system.
-It is a coaxial system in which fresh gas
flows
through a narrow inner tube within outer
corrugated tubing
-It functions like T-piece except that tube
supplying FG to the patient is located
inside the reservoir tube.
-Bain circuit

36. -Length-1.8 meters.
-Diameter of tube-22mm(transparent,carries
expiratory
gases)
-Diameter of inner tubing-7 mm(inspiratory)
-Resistance-Less than0.7 cmH2O
-Dead space-Outer tube upto expiratory valve(
around
500ml=TV)
-Flow rates-100-150 ml/kg/min for controlled
ventilation. Average 300 ml/kg/min for
spontaneous ventilation
-
Specification
s

37. ---Spontaneous respiration: The breathing
system
should be filled with FG before connecting to
the patient. When. the patient takes an
inspiration, the FG from the machine the
reservoir bag and the corrugated tube flow
to the patient.
---During the expiration there is a continuous
FGF
into the system at the patients end.
The expired gas gets continuously mixed
with
the FG as it flows back into corrugated
tubing
and the reservoir bag
Bain system (Mapleson D)
Functional Analysis

38. ---Once the system is full the excess gas is vented to
the
atmosphere through the valve situated at the end
of
the corrugated tube near the reservoir bag.
During
the expiratory pause the FG continues to flow and
fill
the proximal portion of the corrugated tube while
mix gas is vented through valve.
---During the next inspiration , the patient breathes
FG
as well as mixed gas from the corrugated tube.
---It is calculated and clinically prove that
FGF

39. -Controlled ventilation : To facilitate intermittent positive
pressure ventilation, the expiratory valve has to be
partly
closed so that it opens only after sufficient pressure
has
developed in the system. When the system is filled
with
fresh gas, the patient gets ventilated with the FGF
from
the machine, corrugated tubing and the reservoir bag.
-During expiration expired gas continuously gets mixed
with
FG that is flowing into the system at the patient end.
During the expiratory pause the FG continues to enter
the
system and pushes the mixed towards the reservoir.
-When next inspiration is initiated , the patient gets
ventilated with the gas in the corrugated tube i.e

40. BAIN CIRCUIT AND Its FUNCTIONS

41. -Valve less breathing system used for
children
upto 30 kg.
-Suitable for spontaneous and
controlled ventilation
Components are as follows
-T shaped tubing with 3 ports.
-FGF delivered to one port
-2nd port goes to patient & 3rd to reservoir
tube.
-Mapleson E and F

42. -Mapleson E and F

43. Mapleson F
-The most commonly used T –piece system
is
the Jackson-Rees’modification of Ayre’s
T- piece (sometimes known as the
Mapleson F)
-This system connects a two ended bag to
the expiratory limb of the circuit gas
escapes via the tail of the bag.

44. -Plastic angle mount
-Plastic Ayre’sT-piece
-Corrugated rubber hose.
-Reservoir bag of 0.5- 1 lit capacity.
-Green PVC 1.5 meter long tube with plug that fits into the
fresh gasoutlet of theBoyle’sapparatus.
-Gas flows required -2-3 times MV.
-Dead spce-1 ml/lb( 1KG=2.2LBS)
-Tidal volume- 3 times dead space.
-FGF flushes expiratory limb during the pause.
-Expiratory limb should be more than TV to prevent air
dilution
and rebreathing in spon. Breathing child.
It comprises of the
Following

45. ---This allows respiratory movements to be more
easily
seen and permits intermittent positive ventilation if
necessary. The bag is however not essential to
the
functioning of the circuit.
---IPPV may be performed by occluding the tail of the
bag
b/w a finger and a thumb and squeezing bag.
---Alternatively , a‘bag-tail valve’,whichemploys an
adjustable resistance to gas flow, may be attached
to
the bag tail. This causes the bag to remain partially
inflated and so facilitates one handed performance
of
IPPV.
---Another aid to IPPV is Kuhn bag which has gas
outlet
on side of bag.
---Toprevent rebreathing , system requires a minimal

46. --
Advantages
--Compact, light weight, no drag to
ETT.
-- Inexpensive, easy to use and
sterilize
-- No valves
-- Minimal dead space
-- Minimal resistance to breathing
- Economical for controlled
ventilation
--Dis advantages:-Kuhn
bag
-- The bag may get twisted and
impede breathing
-- High gas flow requirement
-- Lack of humidification
-- USES
-- Children under 20 kg weight

47. THANK YOU