MAPLESON MAPLESON BREATHING SYSTEMSBREATHING SYSTEMS

MODERATOR : DR RANJAN R KMODERATOR : DR RANJAN R K

PRESENTER : DR NIKHIL M P PRESENTER : DR NIKHIL M P

History

In 1954 Mapleson described and analyzed Five different anaesthetic breathing systems & referred as Mapleson A – E.

Bain circuit in 1972 by Bain & Spoeral

In 1975 Willis et al described F system & added to above.

In 1976 – Lack circuit .

CLASSIFICATIONCLASSIFICATION

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

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

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

Breathing systems

Bidirectional flow & without carbondioxide absorption & Semiclosed system

MAPLESON SYSTEMS

Mapleson’s assumptions

1. Gases move enblock fresh gas,dead space

gas,alveolar gas

2. Reservoir bag continues to fill,without offering any resistance till it is full

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.

Afferent Afferent reservoir reservoir systemssystems

MAPLESON A SYSTEMMAPLESON A SYSTEM

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

MAPLESON A

MAPLESON A

Lack’s modificationLack’s modification

Expiratory limb –from patient end to APL valve at the machine end of the system2 forms

dual tube (parallel) tube-within-a-tube(coaxial)

LACK’S MODIFICATION

Functional Functional analysisanalysis

Spontaneous Spontaneous breathingbreathing

MAPLESON A- spontaneous respiration

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.

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.

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.

MAPLESON A SPONTANEOUS

Controlled Controlled ventilationventilation

MAPLESON A- controlled ventilation

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.

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.

MAPLESON A - CONTROLLED

TESTS FOR MAPLESON A TESTS FOR MAPLESON A SYSTEMSSYSTEMS

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.

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

FGF RequirementFGF RequirementSpontaneous : equal to minute

ventilation Controlled :very high & difficult to

predict.

MAPLESON B SYSTEM

MAPLESON C SYSTEM

MAPLESON A,B,C

Efferent reservoir system

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.

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.

Mapleson D system

MAPLESON D

BAIN’S CIRCUIT

Functional analysis

Spontaneous Spontaneous respirationrespiration

MAPLESON D - Spontaneous respiration

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.

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.

d. During next inspiration,patient breaths FG & mixed gas.

MAPLESON D CONTD.

Controlled ventilation

MAPLESON D-controlled ventilation

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.

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.

BAIN’S CONTROLLED.

FGF RequirementFGF RequirementSpontaneous : 1.5 to 3 times minute

ventilation ( 100 to 300 ml/kg/min)

Controlled : 1 to 2 times minute

ventilation

MINUTE VENTILATION

FRESH

GAS

FLOW

PaCO2

Almost same PaCO2- for FGF from 100 to 240ml/kg/min

Tests for Mapleson DTests for Mapleson D

By occluding the patient end & closing the APL valve,pressurizing the system

Open the APL valve

Bag deflates easily

TESTS FOR MAPLESON D CONTD.

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

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

AdvantagesAdvantages Can be usedin controlled/spontaneous respirationAdults & Pediatrics Portable,Light weightScavenging of exhaled gases

Hazards Hazards Accidental disconnection of inner tube from machine end.

‘Double back’ itself & cause obstruction to FGF.