1

Rationale and Evidence for

Airway Clearance
Techniques
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Contents
• Functional anatomy of the Respiratory tract
• Mucus and its role in airway clearance
• Mechanism of an effective cough
• Airway clearance techniques
• Conventional
• Advanced
• literature
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Functional anatomy of the respiratory tract

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• Upper respiratory tract

• Nasal cavity
• Oral cavity
• Pharynx
• Larynx

• Lower respiratory tract

• Trachea
• Tracheo-bronchial tree
 5

Functions of upper respiratory tract

• Conduction of gas
• Filter
• Humidification of the inspired air
• Sense of smell and taste
• Phonation
• Protection of the lower airways
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Nose
• Nose is composed of bony and cartilagenious
parts.
• The upper 1/3rd is primarily bony where as lower
2/3rd is cartilagenious
• Nasal cavity is divided into right and left halves
by nasal septum
• Nasal cavity extends from the nostrils to the
nasopharynx posteriorly
 7

• Anterior portion of nasal cavity is composed of

stratified squamous cells – skin, hair follicles
and hairs
• The rest of the cavity – respiratory mucus
membrane which is composed of ciliated
pseudostratified epithelium and goblet cells
 8

Oral cavity
 9

Oral cavity
• Anterior roof is called the hard palate and is
formed by maxillary bone
• Posterior portion is called soft palate
• Uvula
• Walls are formed by cheeks
• Floor by tongue
 10

• Mucosal surface of the oral cavity also provides

humidification and warming of inspired air
 11

Pharynx
• Space behind oral and nasal cavity
• Divided into naso, oro and laryngopharynx
 12

• Nasopharynx is the portion that lies above soft

palate and is lined with ciliated, columnar
epithelium

• Oropharynx extends from soft palate to base of

tongue

• Laryngopharynx extends from base of tongue to

opening of oesophagus
 13

• Enlargement of lymphoid tissue can cause

partial or complete airway obstruction

• Base of tongue can obstruct airway by touching

the posterior pharyngeal wall
 14

Larynx
• Lies between upper and lower airways in
anterior portion of the neck at the level of 4,5,6th
cervical vertebrae

• Complex structure composed of cartilages and

cords

• Largest laryngeal cartilage is thyroid cartilage

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• Laryngeal mucosa is composed of stratified,

squamous epithelium above vocal cords and
pseudostratified, columnar epithelium below
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Lower Respiratory tract

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Trachea
• Adult trachea is approx 12 cms long and 2-3cms
in diameter

• 16 – 20 C-shaped cartilagenous rings – support

and maintain trachea as an open ring

• Trachea extends from the cricoid cartilage upto

the articulation point between the manubrium
and the body of sternum i.e angle of louis
 22

• It divides into 2 main stem bronchi

• The mucus membrane of the trachea contains

columnar ciliated epithelium and goblet cells

• 1 ciliated epithelial cell – 275 cilia

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Main stem, lobar and segmental

bronchi (generation 1-4)
trachea

Right main stem Left main stem

bronchus bronchus

-> 20-30 degrees -> 45-55 degrees

from the trachea from the trachea
-> Wider and shorter -> Narrow and longer
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Sub-segmental bronchi (generation 5-7)

Bronchioles( generation 8-11)

• Diameter of these airways become progressively

smaller but the cross-sectional area increases
because of the increase in the no of divisions

• Mucus membrane – same

• Cilia- sparse
 26

Terminal bronchioles (Generation

12-16)

• Diameter approx 1 mm

• Cartilage is no longer present to provide

structural rigidity

• The epethelium is cuboidal – no longer ciliated

• Cross sectional area increases sharply

 27

Respiratory bronchioles
(Generation 17th – 19th)

• Transitional zone

• Walls consist of cuboidal epithelium

interspersed with few alveoli

• No of alveoli increases with each generation

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Alveolar ducts
(generation 20th – 22nd )

• alveolar ducts arise from terminal respiratory

bronchioles and don’t have walls

• Their walls are composed entirely of the alveoli

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Alveolar sacs ( generation -23)

• Same as alveolar duct except that it ends in blind
pouches

• Each alveolar sac consists approx 17 alveoli

• Alveolar epithelium has 2 types of cells

• Type 1 and type 2

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Mucus
• Mucus is produced in the goblet and submucosal
glands containing 95% water, 2% glycoproteins,
1% carbohydrate, trace amt of lipids and RNA

• Mucus lines the airways from trachea to alveoli

• 2 separate layers - sol layer

- gel layer
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• Sol layer – lies on the mucosal surface and

contains high concentration of water

• Gel layer – superficial and viscous because of its

low water concentration
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Mucociliary escalator

• Cilia beat in a coordinated and unidirectional

manner propelling a sheet of mucus in the
cephalad direction from the lower repiratory
tract to the pharynx where it is swallowed or
expectorated
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Beating frequency of cilia- 20

strokes/second
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• This moving staircase of cilia helps in propelling

of mucus upto the trachea is essential for airway
clearance

• Removal of the mucus occurs through effective

coughing from central airways
 36

This finely coordinated mechanism is

compromised by factors :
dehydration
Smoking
Hypoxia
Inflammation or pathological conditions

Impaired mucociliary clearance predisposes to

infection
 37

Mucociliary clearance
 Normal clearance requires:

1. Patent airway
2. Functional mucociliary escalator
3. Effective cough
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Mechanism of Cough
• 4 stages

Stage 1 • Adequate inspiration

Stage 2 • Glottal closure

• Building up of
Stage 3 Intrathoracic and intra
Glottal opening and expulsion
Stage4 abdominal pressure
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Phases of cough reflex

• Abnormal stimulus like
inflammatory,
mechanical, chemical or
thermal agents

• Stimulates sensory
fibres

• Impulses transmitted to
the medulla
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• Afferent impulses
received

• Reflex stimulation of
respiratory muscles

• Initiation of inspiration

• Range 1-2L
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• Reflex nerve impulses

cause glottic closure &
forceful contraction of
expiratory muscles

• Rapid rise in alveolar and

pleural pressure by
100mmHg
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• Glottis opens, initiating

the expulsion phase.

• With the glottis open, a

large pressure difference
is established between the
alveoli and the airway
opening.
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Causes of impaired cough reflex

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• Postoperative patients have an impaired airway

clearance mechanism and the amount of mucus they
produce in the post operative period is often
increased
Smith and
Ellis,2000
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Peak cough flow rate

• A simple clinical test that objectively assesses the
patients coughing capacity

• Patient is asked to cough as forcefully as possible

through the peak flow meter
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• Normal values of PCF in healthy adults is 240-

400 litres. Females have low values as compared
to males and PCF is inversely proportional to age
Fernanda EF Cardoso,2012

• PCF must be higher than 160 litres to produce

effective cough
Gauld LM, 2005
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Problems due to impaired airway clearance

• Airway obstruction
• Mucus plugging
• Atelectasis
• Impaired gas exchange
• Increased work of breathing
• Infection
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Airway clearance techniques

• It involves the use of noninvasive techniques
designed to help mobilize and remove secretions and
improve gas exchange in patients with impaired
mucociliary clearance or ineffective cough
mechanism
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Goals of Airway Clearance techniques

• Reduce airway obstruction by mobilizing and
removing retained secretions

• Improve gas exchange

• Reduce work of breathing

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Indications
• Cystic fibrosis

• Multisystem genetic disease of the exocrine

glands

• Copious, purulent and thick secretions and

mucus plugs the peripheral and central airways

• Recurrent bacterial infections destruction

of the bronchial walls or bronchiectasis
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• Lung function is seen to be deteriorating when

regular treatment of percussion and postural drainage
was stopped
Desmond 1983; Reisman 1988
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Bronchiectasis
• A breakdown of the elastic tissue in bronchial wall 
severe dilatation
• Inflamed mucosa and copious purulent secretions are
present
• Airway clearance has shown benefits in mobilisation
of sputum

Gallon 1991; Mazzaco 1985

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Atelectasis
• Collapse of alveolar segments due to retained
pulmonary secretions resulting in mucus plugging
• In cases of thoracic or abdominal surgeries under GA
• ACT’s are indicated due to mucus plugging

Hammon , 1981 ; Marini , 1979

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Respiratory muscle weakness

• Seen in neurological or metastatic cases
• Tendency to hypoventilate or have increased work of
breathing
• Inadequate, weak or ineffective coughing
mechanisms
Massery , 1987
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Mechanical ventilation
• Patients who are on ventilator support or comatose
are at risk for atelectasis
• Airway clearance is a standard practice in the
management of patients on mechanical ventilation

Dickman, 1987; Branson,

2007
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Neonatal Respiratory Distress Syndrome

• Surfactant production is decreased

• Technique to be monitored carefully

Crane, 1995
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Methods in Airway Clearance Techniques

• Dr MacMohan – 1915

• Soldiers with injuries to lung,pleura and

diaphragm

• Remarkable improvement in patients condition

within one week of the breathing exercises
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Conventional Advanced
1.) Positive expiratory
techniques
1.) Postural drainage
2.) Mechanical
Insufflation-exsufflation
2.) Forced expiratory
techniques
3.) HFCWO
3.) ACBT
4.) Intra pulmonary
percussive ventillation
4.) Autogenic drainage
5.) Acoustic airway
clearance
 60

Postural drainage
• Passive technique in which patient is placed in
positions that allows gravity to assist with the drainage
of secretions in the bronchopulmonary tree

• Each lobe to be drained is aligned so that gravity can

mobilize the secretions from periphery to central
airways

• Other techniques like percussions, vibrations and

ACBT can be used as adjuncts to PD position
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Postural drainage consists of:

• Turning
• Postural drainage
• Percussions
• Vibrations
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Postural drainage positions

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• Duration in each position and total duration of

the treatment depends on the quantity of
secretions and the no of areas to be drained

• 10-15 minutes in each position for an adequate

drainage to take place

• Bad areas should be drained first

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• Recent radiograph or bronchogram should be

used to isolate the affected areas

• Never to be performed immediately before or

after meals
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Indication
• Cystic fibrosis
• Bronchiectasis, COPD
• Pneumonia
• Presence of foreign body in airway
• Prevent accumulation of secretions – prolong bed rest
or after general anesthesia
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Contra-
indications

AARC Clinical Practice

Guidelines,
1991
 68

Advantages Disadvantages
• Easy to learn Adherence to PD

• Minimal cost Dependence on the

caretaker
• Easier to administer

• Can be coordinated with

other activities of the
patient
 69

Turning
• Rotation of the body around a longitudinal axis

• Also called kinetic therapy or continuous lateral

rotational therapy

• Primary purpose of turning is to :

• Promote lung expansion
• Improve oxygenation
• Prevent retention of secretions
• Reduction in venostasis and prevention of skin ulcers
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Airway clearance techniques

… Contd
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Percussions
• Chest clapping

• Traditional approach for mobilization of

secretions
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Rationale for Percussions

• Percussion involves clapping of the chest wall at a
frequency of approximately 3-6 Hz in order to
produce an energy wave, which is transmitted
through the chest wall to the airways

• This wave loosens the secretions and moves the

mucus proximally which can be removed by
coughing or suctioning
 73

• Inspiration as well as expiration

• Rate of percussion – 100 to 480 times/min
• A thin towel/gown should be covering the area of

percussion
• Not to percuss on breast tissue or bony prominences
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• Spinous process of vertebrae, spine of scapula,

clavicle and floating ribs

• Hand held mechanical percussor can be used to

minimize fatigue

• Tenting of finger, padded rubber nipples or bell of

stethoscope can be used to percuss the chest wall of
an infant
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• Manual and mechanical percussions are equally

effective in removing of secretions.
Redmond A; Maxwell M, 1979

• Mechanical chest percussion may be a safe

intervention to use on neurologically injured patients
who are at risk for intracranial hypertension
Olson et al, American Journal of Critical Care, 2009
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• Percussion may increase hypoxemia but this may be

prevented if combined with thoracic expansion
exercises.
Falk M et al, 1984
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Advantages

• Enhance the secretion clearance

• Percussions + PD -> decreases treatment time
• Sedative effect in infants

Disadvantages
• Not tolerated in post operative patients
• Injury to caregiver
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Vibrations and Shaking

• Vibrations are sustained co-contraction of caregiver’s
upper extremity to produce vibratory force while
applying pressure to chest wall

• Applied at the peak of inspiration

following the movement of
chest deflation

• Frequency of vibration – 12 to 20 Hz
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• Shaking is concurrent, compressive force to chest

wall, applied at the peak of inspiration and a
bouncing pressure is continued till end of expiration

• Frequency of shaking – 2 Hz
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• Significant improvements seen in total lung

compliance after treatment with PD, percussion and

vibration in mechanical ventilated patients

Mckenzie CF, 1980
 81

Advantages
• Enhances mobilization of secretions
• Better tolerated in post surgical patients
• Stretch on the muscle during expiration may
encourage deeper inspiration
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Active cycle of Breathing technique

(ACBT)

• Repeated cycles of 3 ventilatory phases:

Breathing control
Thoracic expansion exercises
FET
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• Breathing control phase:

- TV breathing with relaxation of upper chest and
shoulders

• Thoracic expansion phase:

- This phase consists of deep inspiration and followed by
percussions or vibrations given by the therapist during
expiration. This phase helps to loosen secretions

• FET (1-2 huffs)

- Mid to low lung volume huff– moves secretions from
peripheral to upper airways
- High lung volume huff– clearance of upper airway
secretions
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Rationale:
• Breathing control phase:
• This phase between the other phases is essential
to prevent bronchospasm

• Thoracic expansion phase:

• This phase increases lung volumes and promotes
collateral ventilation
• Collateral ventilation allows air to get behind the
secretions and help in mobilizing the secretions
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• Forced Expiratory Technique:

• Based on the principle of ‘Equal pressure point’

• FET produces compression of the airways distal

to the EPP

• A huff from high lung volumes cause

compression of trachea and bronchi which
moves secretions from these larger airways

• A huff from low lung volumes shifts EPP more

peripherally which mobilizes more peripheral
secretions
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Advantages
• Decrease in oxygen saturation in PD and percussions
has been prevented by use of ACBT

• Young children can perform (more than 3-4 yrs)

• Easily tolerable
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Disadvantages
• Requires caregiver to assist the patient with the
technique
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Autogenic drainage
• Introduced by Chevaillier in 1976

• Self drainage

• 3 phases

• Use diaghragmatic breathing to mobilize

secretions by varying expiratory airflow
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• 3 Phases

Unsticki Collectin
ng Phase g Phase

Evacuati
ng Phase
 90

• No equipments required

• Position of the therapist should be either on the

side or behind the patient

• One hand should be placed on the abdomen and

the other placed on the upper chest

• Average time of treatment 30-45 minutes

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Advantages Disadvantages

Attention and
Children above 12 years of age can
perform independently
concentration
Doesn’t require PD position Unco-operative
patients
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???????
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Positive expiratory techniques

One way breathing valve and an adjustable
expiratory resistance

Backpressure to stent the airways open during

exhalation

Improves Collateral ventilation

Pressure builds up distal to obstruction & promotes

movement of secretions towards the larger airways
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• PEP breathing reinflates the collapsed alveoli

and improves air distribution in the collateral
channels – pores of kohn and channels of
lambert
• Supplimental O2 and nebulization can be
delivered during treatment with PEP
• A manometer in the circuit determines and
monitors the pressure generated by the pt.
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Low-pressure PEP

Resistance adjusted so as to
achieve pressure between 10 to
20 cm of water during active
expiration
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PEP devices
• Acapella

• TheraPEP

• Flutter

• Quake
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Acapella
 98

• High frequency oscillation device

• Mouth piece attached to the unit counterweighted

magnet to create airflow oscillation and a dial to adjust
expiratory resistance

• Green for patients with expiratory flow of 15L/min

• Blue for patients with expiratory flow less than

15L/min
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Thera-PEP
 100

• Mouth piece

• Expiratory resistor – with 6 options of

resistance

• Detectable pressure monitoring port

• Pressure Indicator - provides immediate,

visual confirmation of pressure range of 10– 20
cm H20. Accurate pressure readings in any
positions, at any angle

• It also has fitting for nebulizer

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Flutter
 102

• On exhalation, steel ball moves up and down the cone causing

vibrations of the air

• Pressure maintained is 5 to 35 cm of water

• Prevents airway compression and improves airflow

• Effect of vibration received can be regulated by changing the

angle of the device

• Inexpensive, portable and easy to use

 103

Quake
• Mouth piece integrated with the outer part

• Crank to regulate airflow and allows user to manually

adjust the frequency of vibration

• Wider range
oscillation
frequencies
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Mechanical Insufflation-Exsufflation
• This device delivers a positive breath of 30 to 50
cm of H2O over a period of 1 to 3 secs via a face
mask or tracheal airway

• Airway pressure is then abruptly reversed to -30

to -50 cm of H2O for 2 to 3 secs

• Creates mechanical cough

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• Peak expiratory cough flow obtained with this

device is far better than manually assisted
coughing
Bach Jr, 1996

• Patients tend to prefer MIE to suctioning

because airway clearance occurs without the
discomfort and tracheal trauma
Dean et al, 1996
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High-Frequency Chest Wall

Oscillation

 It consists of
 Air pulse generator
 Inflatable vest

 Sensation similar to mechanical percussion but

differs significantly in its mechanism of action

 Principle : differential airflow i.e. the expiratory

flow rate is higher than inspiratory flow rate
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• HFCWO also decreases the viscosity of the

mucus making it easier to mobilize

• Care should be taken of the fitting of the vest in

patients with nausea, abdominal and chest wall
discomfort
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• The first HFCWO system was developed by Vest

• This device provides oscillations to the entire

thoracic cavity at the varying frequencies
( 5 – 25 Hz)

• Small volumes of gas are injected into and

withdrawn from the vest at a rapid rate creating
oscillating motion
 111

• Lung volumes expired tends to increase with

lower frequencies ( less than 10 to 12 Hz)

• Flow rates increase with higher frequencies ( 12

to 20 Hz)

• Continuous aerosolized medications or saline

can be administered which assists in secretion
mobilization
 112

Advantages
• Independently used

• Can be used in children as young as 2 yrs

• Can be used with mechanical ventilation

• No positioning required

• Saves time of the caregiver

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Disadvantages
• Cost of the equipment
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Intrapulmonary Percussive Ventilation

• IPV is an airway clearance method that
simultaneous delivers intrathoracic percussions
and aerosolized solution for bronchodialation

• Phasitron is the functional component in IPV

 115

• The Phasitron provides high frequency impulses

during inspiration while positive expiratory
pressure is maintained during expiration

• The pressure generated is between 10 and 30 cm

of H2O

• Works in a manner similar to HFCWO except that

pneumatic device delivers oscillations internally
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• A mouth piece delivers high flow rate mini-

bursts of gases into the lungs at rates of 100 –
240 cycles/min

• Continuous pressure is maintained while

pulsatile and percussive intra-airway pressure
rises and dilates the airways enhancing intra-
bronchial secretion mobilization
 118

• This device provides percussion at 6 to 14 Hz

with a positive expiratory pressure of 10 to 20
cm of H2O and simultaneous delivery of aerosol
 119

Changes in the pressure and frequency of the airflow

Stabilize airways and decrease the viscosity of

secretions

Increased sputum mobilization

- Downs AM 2004
 120

• IPV has been found to be as effective as postural

drainage and percussions in improving
pulmonary function and sputum expectoration
- Natale 1994
 121

Advantages:
• Comfortable and independence

• Home use

• Less expensive than HFCWO

 122

Disadvantages:
• Not tolerated well by young patients

• Complaints of chest fullness and claustrophobia

• Expensive than other ACT

 123

Acoustic Airway Clearance

• Use of acoustic vibrations to clear secretions
from the lungs

• The frequencer is the device that produces

mechanical vibrations and acoustic oscillations
to mobilze the secretions
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 125

• This device targets specific areas of the lungs

• Similar to HFCWO however provides oscillations

of muh higher frequencies i.e. 25 to 60 Hz
 126

• Acoustic airway clearance is safe and as effective

as conventional techniques in clearing secretions
in patients with Cystic fibrosis
Cartim M et al, 2006
 127

Advantages
• Specific areas of the lug can be targeted

Disadvantages
• expensive
 128

Factors affecting selection of ACT

• Motivation
• Patient’s goals
• Physician goals
• Effectiveness
• Patient’s age
• Patient’s ability to learn
 129

• Skills of therapists

• Fatigue

• Need for assistants or equipment

• Limitation of technique based on disease type and

severity

• Costs
 130

Adjuncts to ACT

• Antibiotics

• Bronchodilators

• Anti-inflammatory drugs

• Mucolytics

• Nutrition
 131

Impaired
airway
clearance

Mucus Mucus
retention plugging
ACT

Lung damage
Increased mucus
Lung
production infection
 132

Airway clearance techniques for chronic obstructive

pulmonary disease

• Level of significance – 1a
• Osadnik CR et al
• Cochrane Database of Systematic Reviews 2012, Issue 3
 133

Objective :
Primary
To determine whether ACTs have beneficial effects on
exacerbations, hospitalisation and HRQoL in people with
AECOPD and stable COPD.
Secondary
To assess whether:
• airway clearance techniques are effective in both
 134

Studies included
Randomized parallel trials and randomized cross-
over trials which compared an ACT to no treatment,
cough or sham ACT

Participants
COPD, emphysema or chronic bronchitis
 135

Iterventions
Conventional techniques, breathing exercises, and
PEP or mechanical devices

Outcomes
Primary :
1. Rate of, or time to, AECOPD, defined according to the
investigators’ definition.
2. Respiratory-related hospitalisations and resource
utilisation
 136

Secondary outcomes included : -

• Pulmonary function
• Gas exchange
• Symptoms
• Sputum clearance and expectoration
• Exercise tolerance
• Mortality (all-cause)
 137

Results
• 13 randomised controlled trials (RCT) on 629
participants and 15 randomised cross-over trials
(RXT) on 278 participants.

• 18 studies in quantitative synthesis (meta-analysis)

• qualitative or narrative data from the remaining 10

studies
 138

Conclusion
• In AECOPD, ACT use is associated with a reduced
need and duration of ventilatory assistance
• Small reduction in length of hospital stay
• No effect of ACTs on future exacerbations or
hospitalisations was evident
 139

• In stable COPD, evidence from single studies

suggests ACT use may reduce the need for hospital
admission and improve HRQoL

• No convincing evidence of other benefits of ACTs in

acute or stable COPD
 140

Airway clearance techniques for

bronchiectasis
• Level of evidence – 1 a

• Lee AL et al

• Cochrane Database of Systematic Reviews 2013, Issue 5

 141

Objective of the study:

• Primary:
to determine the effects of ACTs on the rate of
acute exacerbations, incidence of hospitalisation
and HRQOL in individuals with acute and stable
bronchiectasis.
 142

• Secondary: to determine whether

a) ACTs are safe for individuals with acute and

stable bronchiectasis and

b) ACTs have beneficial effects on physiology and

symptoms in individuals with acute and stable
bronchiectasis
 143

Studies included:
• Randomised controlled parallel and cross-over
trials that compared an ACT to no treatment,
sham ACT or directed coughing in participants
with bronchiectasis.

• Participants :
• Adults and children with Bronchiectasis
 144

Interventions:
• Conventional techniques, breathing exercises,
and PEP or mechanical devices
 145

Outcomes:
• Primary outcome:

• Rate of, or time to, Acute exacerbation, defined

according to the investigators’ definition.

• Incidence of hospitalization

• Quality of life measured either by generic or

disease specific HRQOL instrument
 146

• Secondary outcome:
• Pulmonary function
• Gas exchange
• Symptoms
• Days of antibiotics
• Sputum clearance and expectoration
• Exercise tolerance
• Mortality (all-cause)
 147

Results :
• 5 studies were included consisting of 51
participants

• 4 RCTs were carried out on adult patients and 1

on children with bronchiectasis
 148

Conclusion:
• ACTs are safe for adult as well as Children with
stable bronchiectasis and there is improvement
in sputum production, select measures of lung
function and HRQOL

• Role of ACTs on acute exaccerbations of

bronchiectasis is not known
 149

A Comparison of Autogenic Drainage and the Active

Cycle of Breathing Techniques in Patients with COPD

• Level of evidence – 1 b

• Savci et al, 2000

• Journal of Cardio-pulmonary Rehabilitation

 150

• Methodology:
30 clinically stable male COPD patients were
randomly assigned to AD or the ACBT treatment
for a 20-day treatment period.

Outcome measure:
Pulmonary function tests, arterial blood gases,
6MWT, and a modified Borg Scale before, and
immediately after the walking test.
 151

• Result:
• AD improved FVC, FEV in 1 sec, PEFR , FEV 25
to 75%, chronic hypercapnia, arterial
oxygenation, exercise performance, and dyspnea
perception during exercise.

• The ACBT increased FVC, PEFR, arterial

oxygenation and exercise performance.
 152

• PEFR increased in AD more than in ACBT.

• In AD treatment, the increase in oxygen
saturation was significantly higher than in ACBT
treatment.
• Chronic hypercapnia improved significantly in
AD treatment than in ACBT.
• No differences were found in other lung
function parameters
 153

Conclusion

• Autogenic drainage is as effective as the ACBT

in cleaning secretions and improving lung
functions. These techniques can be used in
stable COPD patients according to the patients'
and the physiotherapists' preferences.
 154

Effect of Mechanical chest percussion

on intracranial pressure : Pilot study

• Daiwai M et al , 2009

• American journal of critical care

 155

Study population:
Patients who had an episode of elevated ICP were
selected
Control group: 15 pts did not receive chest
percussions

Intervention group: 13 pts received chest

percussions for 10 minutes
 156

Outcome measures
Heart rate, Respiratory rate, Blood pressure, Body
temperature, ICP, cerebral perfusion pressure, and
oxygen saturation, CSF drainage

Results :
• Intracranial pressures for the control group
before, during, and after the study period did not
differ significantly from pressures in the
intervention group, safe to perform
 157

References:
• Cardiovascular and Pulmonary Physical therapy,
Donna Frownfelter , Elizabeth Dean

• Fundamentals of Respiratory Care, Egans 10 th

edition
158