2. BREATHING SYSTEM
• It is the gas pathway connected to patient,
through which gas flows at respiratory pressure.
• ESSENTIAL FEATURES
• Delivery of gas from machine to alveoli in same
concentration as set and in shortest time.
• Effective elimination of CO2
• Minimum dead space
• Minimum resistance
3. DESIRABLE FEATURES
• Conservation of heat.
• Economy of fresh gas.
• Adequate humidification.
• Efficient during spontaneous and controlled ventilation.
• Light weight
• Less theater pollution.
• Convinient during use.
4. COMPONENTS
• BUSHINGS
• Modify internal diameter
of compound.
• SLEEVES
• Alter external diameter.
• CONNECTORS
• Join together two or more
similar components.
• ADAPTORS
• Connect incompatible
components.
• RESERVOIR BAG
• Allow gas to accumulate
during expiration. Allow
more economic use of gas.
• Control or assist ventilation.
• Monitor of patient’s
spontaneous ventilation.
• Prevents patient from
extensive pressure.
• BREATHING TUBES
• Large bore corrugated tube.
• Provide flexible, low
resistance, light weight
connection.
5. • ADJUSTABLE PRESSURE
LIMITING VALVE(APL)
• Control pressure in
breathing system.
• POSITIVE END EXPIRATORY
PRESSURE VALVE
• Maybe unidirectional or
bidirectional.
• FILTERS
• Protect patients from
microorganisms and
airborne particulate
matter.
• Protect anaesthesia
equipment and
environment from
exhaled contaminants.
• TYPES
• MECHANICAL FILTERS
• ELECTROSTATIC FITERS
6. CLASSIFICATION
• Several attempts by many authors have made in regards to
classify breathing systems.
• On the basis of presence or absence of different components,
rebreathing, boundaries, fresh gas flow and many more.
• An attempt has been made by
• Dipps, Eckenhoff, Vandam - MC Mohan
• Moyers - Baraha
• Collins - ISO
• Adriani - Marini, Culver, Kirk
• Conway - Hamilton
• Hall
9. MAPLESON SYSTEM
• MAPLESON A (MAGILLS SYSTEM)
• MAPLESON B
• MAPLESON C
• MAPLESON D (BAIN’S SYSTEM)
• MAPLESON E (T PIECE)
• MAPLESON F (JACKSON REES MODIFICATION OF T
PIECE)
11. • Best for spontaneous respiration.
• APL valve at patient end.
• Fresh gas flow towards machine end.
• Depend on fresh gas flow for CO2 washout so also
called as “flow controlled breathing system’.
• No rebreathing if FGF=MINUTE VOLUME.
• No separation of inspired and expired gases.
• Monitoring of ETCO2 is must.
12. WORKING
Spontaneous respiration-
• During expiration patient exhales
dead space gas followed by alveolar
gas towards the bag.
• Fresh gas also flows to bag.
• When the bag is full pressure
increases and APL valve opens.
• It vents out alveolar gas first followed
by dead space gas if FGF is high
enough.
• If FGF is intermediate some dead
space gas retains in circuit.
• If FGF is low some alveolar gas
retains in system.
During inspiration the gas inhaled will
depend on fresh gas flow.
13. Controlled ventilation-
• During expiration, pressure in
the system remains low so
dead space gas and alveolar
gas remain in corrugated tube
and bag(maybe).
• With start of
inspiration(squeezing of bag)
gases in tube flow towards the
patient that start with alveolar
gases.
• As pressure increases APL
valve opens and gas exits
through valve that includes
fresh gas. So some fresh gas is
vented out and some enter
patient.
14. • TEST
• Occlude patient end, close APL valve, pressurize system by increasing oxygen flow,
if maintained pressure confirms integrity.
15. LACKS MODIFICATION(1976)
• Added expiratory limb which runs from patient connection to
APL valve i.e. towards machine end.
• Parallel(Dual arrangement)
• Co-axial(Tube within tube)
16. • Disadvantages-
• It is inefficient during controlled
ventillation as FGF=2.5*MV
• Should not be used with mechanical
ventilator as entire space becomes dead
space.
18. MAPLESON B
• Fresh gas inlet near patient and distal to APL.
• APL opens when pressure in circuit increases
and mixture of alveolar and fresh gas is
discharged.
• During inspiration mixture of fresh gas and
alveolar gas is inhaled.
• To avoid rebreathing FGF>2*MV i.e. not very
efficient.
22. MAPLESON D
• Fresh gas at patient end.
• Reservoir bag and APL valve at other end.
• BAIN’S SYSTEM(1972)
• Added one tube coaxially.
• Inner tube- Inspiratory (7mm ID)
• Outer tube- Expiratory+ Inspiratory (22mm ID)
• Length 1.8m
• FGF->
• Spontaneous- 150-200ml/kg/min
• Controlled- 70-100ml/kg/min
23. • Advantages-
• Useful in adult patient.
• Allows warming and humidification of gases.
• Useful for controlled ventillation.
• Easily dismantled and sterilized.
• Length of tube is long so machine can be taken away from
patient hence useful in neuro and ENT OT.
• Light weight.
• Can be used with ventilator.
• Disadvantages-
• High fresh gas flow required.
• Can’t be used with intermittent flow machine.
• Disconnection, kink, break, leak at inner tube may go
unnoticed.
24. WORKING
Controlled ventillation-
• During expiration dead space gas
and alveolar gas along with fresh gas
are pushed towards the bag through
the outer tube.
• During expiratory pause more fresh
gas pushes expired gases from tube
to reservoir bag.
• As the bag is squeezed for next
inspiration the pressure pops open
the APL valve lying towards the bag
and vents out the alveolar and dead
space gases along with some fresh
gas and patient inhales maximum
amount of fresh gas accompanied
with some amount of alveolar gas.
25. Spontanous respiration-
• Exhaled gases mix with fresh gas
and move through corrugated
tube towards the bag as the bag is
filled, it exits through APL valve.
• During expiratory pause fresh gas
pushes alveolar gas down the
tubing.
• During inspiration if FGF is high
fresh gas is inhaled. If FGF is low
exhaled gas with high CO2 is
inhaled.
Factors decreasing rebreathing-
High expiratory pause.
Increase I:E ratio.
Slow increase in inspiratory flow rate.
Low flow rate during last part of exhalation.
26. • TESTING
• INNER TUBE
• FOEX –CREMPTON SMITH TEST-
• Set low flow oxygen on flow meter close APL valve.
• Occlude inner tube with finger or barrel of syringe at patient end.
• Observe flow meter indicator.
• If tube is intact and correctly connected bobbin of flow meter will fall due
to back pressure.
• PATHIK TEST-
• Close APL valve, activate oxygen flush.
• Observe bag.
• Due to venturi effect, bag will deflate.
• OUTER TUBE
• Close APL, occlude patient end, pressurize system. If no leak
pressure is maintained.
• When APL opens bag deflates.
28. MAPLESON E
• T-Piece
• Has tubing attached to T piece to form
a reservoir.
• Commonly used to administer oxygen
or humified gas to intubated patient
breathing spontaneously.
31. MAPLESON F
• JACKSON-REES SYSTEM
• Modification of T piece with bag that has
venting mechanism usually a hole.
• For spontaneous ventillation- relief
mechanism is left open.
• For assisted- relief mechanism is occluded
enough to distend bag, respiration is
controlled by squeezing bag.
32. • Advantages-
• Compact.
• Cheap.
• No valve.
• Minimum dead space.
• Minimum resistance to breathing.
• Ventilator can be used.
• Disadvantages-
• Bag may become twisted and impede breathing.
• High gas flow required.
33. Mapelson
System
Fresh gas flow
inlet
APL valve
location
Reservoir bag Corrugated
tubing
Examples
A NEAR BAG NEAR PATIENT PRESENT PRESENT MAGILL,
LACK (co axial)
B NEAR PATIENT NEAR PATIENT PRESENT PRESENT obsolete
C NEAR PATIENT NEAR PATIENT PRESENT ABSENT Obsolete, still
used in
emergency
resuscitation
(AMBU bag)
D NEAR PATIENT AWAY FROM
PATIENT
PRESENT PRESENT Bain (co axial)
E NEAR PATIENT ABSENT ABSENT PRESENT Ayre’s T piece
F NEAR PATIENT ABSENT PRESENT PRESENT Jackson Rees
Modification for
paediatric
patients
