airway clearance techniques and adjuncts

Question 1

What is effective ACT

Answer 1

manipulate airflow –> mobilise secretions –> evacuation.

Aims of ACT:
Reduces airway obstruction and improves ventilation
Prevent progression of lung damage/ delay disease progression

How do airways become obstructed?
Secretions decrease airway diameter – increase in airway resistance
Less obstructed airways become better ventilated
Hypoventilation of obstructed regions
Air can “trap” behind mucous - hyperinflation

Question 2

Indications for ACT

Answer 2

CF, Bronchioctasis, COPD, PCD
NM patients
Ventilated patients

any patient with altered mucociliary escalator +/- cough mechanics

Question 3

physiological airway clearance treatment strategy

Answer 3

open airways get air behind mucus
loosen/ mobilise mucous
transport mucous to proximal airways
evacuate mucous

Question 4

interdependence

Answer 4

Deep inspiration – TV increases
Alveoli expand – this exerts a traction force on surrounding less well expanded alveoli
Air moves into the small airways that are obstructed by secretions

Question 5

collateral ventilation

Answer 5

ventilation of alveoli through passages or channels that bypass normal airways

Question 6

Use of expiratory airflow

Answer 6

NB speed of expiratory airflow - mobilises secretions towards larger airways

Cough
Deep inspiration followed by closure of the glottis
Shearing force detaches mucous from the airways
Chronic lung conditions – chronic cough – narrow “floppy” airways – reduced expiratory flow, reduced cough effectiveness
ACTs should be the primary mechanism for secretions to be mobilised from the middle and smaller airways to the larger airways, followed by one effective cough

Question 7

types of ACT

Answer 7

ACBT
Autogenic Drainage
PEP
Oscillating PEP   -Acapella
                               -Aerobika
                               -Flutter

HFCWO
BiPAP
Cough assist

Question 8

ACBT

Answer 8

Uses interdependence and collateral ventilation during DBExs
3 sec breath hold increase alveolar gas exchange
Huff/ cough to clear

Simple to learn
No equipment
Free!

Question 9

Huff

Answer 9

Open glottis
Shears mucous from airway walls
“Forced expiratory manoeuvres are probably the most effective part of chest physiotherapy” (Van der Schans 1997)
NB- all patients with ‘hyper-secretory disorders’ e.g. CF should be taught how to perform effective FET/huff

Question 10

Autogenic drainage

Answer 10

Utilises gentle breathing at different lung volumes to loosen, mobilise and clear bronchial secretions
Obstructed lung regions ventilated – 3 sec breath hold on TV inspiration, uses collateral ventilation channels
Expiratory airflow is modulated at each phase to move secretions proximally

Question 11

PEP
how it works
indication

Answer 11

Positive Expiratory Pressure
Mask or mouthpiece
One way valve to which expiratory resistors are attached
Manometer included in the circuit
Aim to get a steady PEP of 10-20cmH20 during mid expiration
Breathe at tidal volume with a slightly active expiration

how it works How does it work:
Reduces airway collapse caused by bronchiectasis - breathing out against resistance opens up the airway - collateral ventilation - gets air behind secretions and mobilises secretions from the periphery to the central airways (pressure gradient)
Temporarily increases the FRC
Indications:
CF, Bronchiectasis, patients with a large volume of secretions and where airways close too early on expiration

Some PEP devices can be used to deliver hypertonic saline or nebulised antibiotics e.g. pari PEP

Question 12

PEP technique

Answer 12

Sitting upright with arms resting on a table

Inspiration- just above tidal volumes
Inspiratory pause
Expiration -slightly active 3-4 seconds

Aim to get a stable pressure of 10-20cmH20 during mid
expiration

Typically 12-15 breaths via PEP followed by FET

Cleaning
Cost

Question 13

Oscillating PEP

Answer 13

Combines PEP with oscillations/vibrations
Vibratory effect loosens secretions and can reduce viscoelasticity of secretions

Technique
Inspiration-slightly greater than tidal volume
Inspiratory pause 2-3 seconds

Expiration- slightly active 3-4 seconds

Optimal oscillation frequency is the setting at which
vibrations are most palpable in the lower chest wall

Typically 10-15 breaths followed by FET

Question 14

Acapella/ Aerobika

Answer 14

Oscillations generated during expiration which travel through the airways
PEP temporarily raises FRC

Technique:
Sit with elbows on a table
Start with the dial at “1”
Place the device in your mouth and inhale to slightly above TV (not to TLC)
Hold the breath for 2-3 secs
Breathe out actively for 3-4 secs
Adjust the dial to increase resistance and get the greatest vibratory sensation - palpate
Cycle - breathing control,10-20 breaths, breathing control, 2-3 huffs, cough and expectorate

Question 15

Flutter
how it works
indications

Answer 15

Combined effects of PEP and oscillation
Gravity dependent
Cannot inhale through the device
Need good technique for it to be effective

How does it work:
The rise and fall of the ball creates PEP (prevents airway collapse) and oscillatory vibration of the air within the airways can aid in shearing mucus from the airway wall and therefore mobilise secretions
Provides intermittent PEP in the range of 18-22cm/H20 normal effort and up to 35cm/H20 with expiratory exertion

Indications:
CF, Bronchiectasis, in some COPD patients

Question 16

flutter technique

Answer 16

Sit with elbows on a table
Hold the stem horizontal for initial use
Inhale slightly above TV
Hold the breath for 2-3 secs
Exhale fast but not too forceful (exhale to FRC not ERV)
Continue to exhale to a level slightly further than during normal breathing - prolonged compared to inspiration, keep cheeks of your face stiff
The angle at which you hold the flutter is critical
The angle that gives the greatest fluttering sensation gives the best results
Palpate chest wall and tune the device to the patient
Cycle - breathing control, 10-20 breaths, breathing control, 2-3 huffs, cough and expectorate

Question 17

compare acapella aerobic flutter

Answer 17

Acapella
Not gravity dependent-use in variety of positions
Can inhale through the device

Aerobika
Similar to acapella
More durable
More cost effective

Flutter
Gravity dependant
Cannot inhale through the device
Good technique NB

Question 18

PEP - things to consider

Answer 18

In people with enlarged livers and hernias be careful of high pressures with PEP

Precautions/Contraindications as with NIV - with particular attention to haemoptysis and pneumothorax

Used in different to positions to maximise airway clearance

Question 19

HFCWO

Answer 19

High Frequency Chest Wall Oscillation

How does it work:
Positive pressure air pulses to the chest wall by an inflatable vest
These pulses compress the chest wall at frequencies from 5-30 Hz
Only the air in the airways oscillates

Very expensive compared to other devices
Suggested benefits in CF and neuromuscular conditions

However…
McIlwaine et al., 2013 – results favour PEP over HFCWO

suggestions for use Combining the vest with exercise (treadmill/bike) may be useful
Combining with nebulisers and AD or ACBT
Ramping programmes - pause for clearance through the settings
Can be useful to induce a sample

Question 20

NIV - BiPAP

Answer 20

Bilevel Positive Airway Pressure
Superimposes inspiratory and expiratory pressures on the patients own breathing

IPAP: Inspiratory positive airway pressure
EPAP: Expiratory positive airway pressure
EPAP is useful in controlling upper airway closure, recruiting collapsed alveoli and in overcoming intrinsic end expiratory pressure
Nasal or full face masks
Humidification needs to be included in the circuit

Question 21

NIV- BiPAP - how does it work

Adjunt to ACT

Answer 21

How does it work:
Increase ventilation (tidal volume), increase Pa02 and decrease PaC02, decrease respiratory rate, improves the efficiency of ventilation
Used to manage Type 2 respiratory failure
Nocturnal hypoventilation (in conjunction with O2 therapy)
Can be used as a “bridge” to lung transplant

Contraindications/Precautions:
Undrained pneumothorax, large bullae, unstable CVS, large bullae, facial fractures / traumas, frank haemoptysis, vomiting, agitated patient, decrease consciousness - unable to maintain own airway

Adjunct to ACT
Severe bronchial obstruction (FEV1 < 40% predicted)
Reduced body mass index (BMI < 20 kg.m-2)
Dyspnoeic at rest
Severe pulmonary hyperinflation
Low resting oxyhaemoglobin saturation
(Holland et al., (2003) and Faroux et al., (1999))

NIV should be considered if fatigue is limiting ACT, where desaturation is present during ACT
and if difficulty clearing secretions with other techniques (CF Trust, ACPCF UK Standards of Care (2017))
NIV has been shown to improve FEV1 and fatigue (Dwyer et al., 2015)

Question 22

Cough assist

how does it work

Answer 22

Stimulates a cough through insufflation / exsufflation using positive and negative pressure causing a high expiratory flow
Inhalation phase
Exhalation phase
Pause phase

1 cycle = 1 insufflation, 1 exsufflation and pause
1 sequence = 4-6 cycles
Treatment session = 4-6 sequences

Position for most effective use of the diaphragm and for assisted cough techniques
Finish with inhalation cycles

indications
Patients unable to cough or clear secretions effectively due to reduced peak expiratory flow resulting from high spinal cord injuries, neuromuscular deficits

Bullous emphysema, susceptibility to pneumothorax, pneumo-mediastinum, recent barotrauma, unstable CVS, recent oesophageal surgery, bronchial tumours, base of skull fractures, known diagnosed lung pathology

Question 23

Incentive spirometer

Answer 23

Introduced in an attempt to reduce post op respiratory problems (collapse/ atelectasis) - not intended for airway clearance
Emphasis should be placed on expansion of the lower chest rather than use of the accessory muscles of respiration
Only 2 out of the 3 balls should be raised and the breath sustained for 2-3 secs while they are raised The third ball is a control and should not be raised
Provides visual feedback for the patient but the same effect can be achieved without it

Question 24

Airvo

Answer 24

Humidified oxygen/ room air
Flow 25-60L/min

Secretions
Breathlessness/ wheeze

Question 25

positioning

Answer 25

Fully supported positions take postural control role out → remember dual role of
resp muscles i.e. resp and MSK!

Aims for positioning and ACT
Enhance ventilation to specific lung regions
Use enhanced airflow to aid removal of secretions

Question 26

mobility

Answer 26

Change in body position alters regional ventilation
With mobility, O2 demand increases, minute ventilation increases, lung volumes increase
Increased ventilation = air moves into obstructed areas of lung by interdependence and collateral ventilation

Question 27

Things to consider when choosing an adjunct

Answer 27

Age/ cognition
Compliance
Severity of lung disease
Precautions/ contra indications
Ease of use/ comfort
Cost/ availability