Airway clearance technique 2

Principles of positive pressure expiration

Principles: 

1. Re-inflation of collapsed parts of lungs by collateral ventilation 

→ splinting airways 

→ bring air behind secretions through the interbronchiolar channels ( collateral ventilation ) 

Working principle: 

1. In conditions w/ collapsible airways → airway collapse easily in expiration as the alveolar pressure attenuates in expiration  → secretions are trapped 

2. PEP provides positive pressure to splint the airway open through expiration w/ resistors

Selection principles of PEP

1. Smaller the size of resistor → greater PEP

2. Greater patient expiratory flow → greater PEP 

Selection of optimal PEP 

→ taking 6-8 breaths w/ PEP 

• Pressure of 10-20 cmH2O 

• Maintain correct technique 

• Inspiration: expiration = 1:3 ( 3s breath in → 9s  breath out )

• X increase in WOB/ SOB

Indications for PEP

1. Cystic fibrosis 

2. COPD 

3. Bronchiectasis 

4. Chronic bronchitis 

5. Restrictive lung disease 

6. Post-op secretions/ atelectasis 

7. Collapsible airways; tracheobronchial instability 

8. Productive asthma

Contraindications for PEP

Respiratory conditions 

1. Active haemoptysis 

2. Lung surgery ( lobectomy, transplant ) 

3. Undrained empyema/ lung abscess 

4. Emphysematous bullae 

5. Increased work of breathing 

Cardiovascular: 

1. Haemodynamic instability 

Head/ ENT: 

1. Facial fractures or surgery 

2. Middle ear infection 

3. Sinusitis 

→ X want to increase pressure in the thorax/ head

Application of PEP

Duration: 

Stable disease: 10-15 mins x 1-2/ day 

Post-op: shorter sessions + more frequent → X tolerate longer sessions

Mouthpiece vs Mask requirements

Mouthpiece: more common; need to keep cheeks flat; able to understand to breath in through mouth 

Mask: X keep cheeks flat/ mouth sealed around mouthpiece

Types of PEP

Flutter: beating at 8-16 Hz → natural pulmonary resonance of cilia → help cilia beat at normal rhythm; X breath through the device 

Acapella + aerobika: Can inspire through device

Bubble: X confusion/ cognitive impairment → aspiration w/ water/ bubbles

Autogenic drainage description

Self drainage using breathing control + breaths at various lung volumes to mobilise secretions 

Phases: 

1. Unstick 

2. Collect 

3. Evacuate 

	Activities
Unstick	Lung volume shifted from tidal to residual volume
Collect	Moving lung volumes back to middle volume
Evaluate	Moving lung volume to high volume

→ suppress cough until end of routine

Disadvantage of autogenic drainage

1. Difficult to learn 

2. Uncomfortable 

3. Time consuming 

Duration: 20-45 mins x 2/d

Postural drainage

Using gravity to assist drainage from specific segments 

Positioning: Good lung dependent 

Usually: Modified positions: 

1. X head down tilt → potential gastric reflux 

Used w/ other ACTs

Advantage of postural drainage

1. Using gravity

Disadvantage of postural drainage

Respiratory: 

1. Dyspnoea 

2. Severe haemoptysis 

Cardiovascular: 

1. Aortic aneurysm 

2. Severe  hypertension 

3. Cardiac failure 

Neurological: 

1. Cerebral aneurysm 

2. Cerebral oedema 

3. Raised ICP 

4. Surgery/ trauma to head/ neck 

Gastro: 

1. After meal 

2. Gastroesophageal reflux 

3. Abdominal distension 

4. Preterm infants

Percussion +vibration principle

Principle:  ↑ Cilial beat w/ vagal stimulation  ↓ Mucous cross-links  ↑ Peak expiratory flow  Percussion  Vibration  Inspiration  Y N Expiration  Y Y Vibrations:  → used augment FETs  → fine/ coarse shaking → X shaking skin *Safety:  Palpate bibasal excursion → RoM of ribs  AP sternal movement → is there mvmt

Precautions of percussion + vibration

Precautions: 

1. Rib # 

2. OP

3. Pain 

4. SOB

5. Lung cancer 

Precautions for percussion

1. Bronchospasm 

2. ↓ partial pressure of O2 ( hypoxaemia ) 

→ Min adverse effects: 

1. Add 3-4 TEE 

2. Min length of Rx

Contraindications for percussion + vibration

Respiratory: 

1. Severe haemoptysis 

2. Lung contusion 

3. Severe hypoxaemia 

4. Pulmonary oedema 

5. Bronchospasm, SOB 

6. TB 

7. Acute pain ( pleuritic, surgery ) 
   
   

Cardiovascular: 

1. Severe hypertension 

2. Coagulopathy, thrombocytopaenia 

3. Recently placed pacemaker 
   
   

MSK/ skin 

1. Subcutaneous emphysema 

2. OP, bone cancer 

3. # 

4. Poor skin integrity 

5. Preterm infants

Inhalation therapy principles

Aerosols + nebulisers 

	Purpose	Timing
Bronchodilator	↓ airway resistance  ↑ cilial beat	Before Rx
Mucolytics	↓ viscosity of secretions	Before/ during/ after
Inhaled steroids	↓ inflammation	After

Exercise therapy purpose

1. Loosen secretions → vertical mvmts shear secretions → ↑ mucous clearance 

→ adjunct

Precautions w/ exercise

Precautions: 

1. Safety 

• Ex testing + prescription 

• Monitoring → SpO2/ RPE

• Hydration

• Heat control

Extra care w/ patient populations: 

1. Severe COPD ( hyperinflation/ bronchospasm ) 

2. Deconditioning/ fatigue 

3. Diabetes