airway clearance techniques and adjuncts Flashcards
What is effective ACT
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
Indications for ACT
CF, Bronchioctasis, COPD, PCD
NM patients
Ventilated patients
any patient with altered mucociliary escalator +/- cough mechanics
physiological airway clearance treatment strategy
open airways get air behind mucus
loosen/ mobilise mucous
transport mucous to proximal airways
evacuate mucous
interdependence
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
collateral ventilation
ventilation of alveoli through passages or channels that bypass normal airways
Use of expiratory airflow
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
types of ACT
ACBT
Autogenic Drainage
PEP
Oscillating PEP -Acapella
-Aerobika
-Flutter
HFCWO
BiPAP
Cough assist
ACBT
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!
Huff
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
Autogenic drainage
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
PEP
how it works
indication
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
PEP technique
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
Oscillating PEP
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
Acapella/ Aerobika
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
Flutter
how it works
indications
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
flutter technique
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
compare acapella aerobic flutter
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
PEP - things to consider
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
HFCWO
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
NIV - BiPAP
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
NIV- BiPAP - how does it work
Adjunt to ACT
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)
Cough assist
how does it work
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
Incentive spirometer
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
Airvo
Humidified oxygen/ room air
Flow 25-60L/min
Secretions
Breathlessness/ wheeze
positioning
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
mobility
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
Things to consider when choosing an adjunct
Age/ cognition Compliance Severity of lung disease Precautions/ contra indications Ease of use/ comfort Cost/ availability
