W7 Flashcards
What is airway clearance
Technique/device used to mobilise excessive bronchial secretions and evacuate them from the body
Indications for airway clearance
Raised WCC ++ neutrophils i.e. infection
Weak/ineffective cough compared to baseline
Change in sputum colour or volume
Hx of resp conditions that impairs MCC or has increased sputum
Consolidation on CXR
Tracheostomy
Long term O2 therapy with no humidification i.e. secretions are dry
Environmental toxic gas exposure
Recent exposure to high altitude
Raised CRP indicating inflammation
Raised Na indicating dehydration
Mucus plugging
Cough peak flow <160L/min (can’t clear) OR cough peak flow <270L/min (likely to be retained)
- Important for pt. with neuromuscular disorders
What is involved in the mucocillary esclator
Hairlike extensions of ciliated epithelium beat particles along
Serous fluid/Sol layer which bathe cilia and allow them to beat properly so they don’t get tangled
Mucus that captures foreign particles and secretes goblet and submucosal cells
Alveolar macrophages engulf foreign particles
Cough is reflexive and uses high speeds of up to 500L/min PEFR and can rise intrapulmonary pressure up to 300mmHg
What does a cough rely on
Increasing lung volume (inspiration)
Closing vocal folds/glottis
Ability to contract abdominals and intercostals -> to build intrapulmonary pressure and then reverse all this to explode the cough out
What impairs mucocilliary clearance
Congenital defects of cilia primary cilial dyskinesia (incoordination of cilia therefore mucus wont move
Cigarette smoke and other noxious particles paralysis of cilia and damage to macrophages
Chronic resp disease bronchiectasis = damage to epithelium and cilia = dead
Changes in character of mucus due to disease, dehydration or humidity
Excess secretions which overload the system
Alcohol reduces maturation of macrophages, affects cell membrane and metabolism
Oxidant gases redcies phagocyotsis therefore cant absorb bad particles
Alveolar hypoxia altitude and COPD
Weak/ineffective cough cant actually expel sputum
What aids mucocilliary clearance
Pharmacological mucoactive agents (hypertonic saline), bronchodilators (beta agonsits, theophylline, corticosteroids, cholingerics)
Moderate intensity PA
Increase water intake
Warmed and humidified air use AIRVO
What are indications for mucocilliary clearance
Sputum production > normal usually for chronic sputum production conditions
- Are you coughing anything up now? How much? Normal?
Sputum retention
Impaired MCC
IF YOU SEE ANY OF THESE 3 YOU KNOW IMPAIRED AIRWAY CLEARANCE IS A PROBLEM FOR THIS PATIENT
What ACTs are not reliant on therapist or device
ACBT, Autogenic drainage, exercise, GAD (postural drainage)
What ACTs require devices
PEP, Oscillating PEP, High Frequency Chest Wall Oscillation, Inhalation Therapy
What ACTs rely on others/PTs
Vibrations and percussions
What are the 3 components of ACT
- Ventilate the targetted area aiming to increase lung volumes
- Mobilise secretions to the mouth PIF<PEF
- Evacuate the secretions
Outcome measures for ACT
Short Term:
Sputum volume, colour
Sp02
Oxygen Therapy Fi02 requirement
Auscultation
RR, SOB, WOB
Breathing Pattern
Improved Cough/Huff technique
Medium Term:
Spirometry (FEV1, FVC) CXR
ABGs
Dyspnoea (RPE)
Exercise capacity
Long Term:
LOS
Number of exacerbations
HRQOL
What is EPP
The point in the airway when the pressure outside of the airway in the pleural space (Pip ) equals the pressure inside of the airway (Pbr ).
Pressure inside = pressure outside
How does EPP apply to FET
On FET Pbr drops more rapidly so EPP can occur prior to rings and where the EPP occurs is dependent on the initial lung volume
EPP increases turbulent airflow as same volume of air is trying to pass through smaller diameter of airway therefore increased velocity
What is ACBT
A set of breathing techniques that are targeted specifically to the patient to assist with sputum clearance
What are the physiological effects and mechanism of ACBT
Technique produces dynamic compression and collapse of the airways downstream of the equal pressure point (EPP), creating a “pinch point” and increased turbulent airflow
TEE:
Increases the lung volumes which then increase amount of air flow, opening collateral airways, allowing air to go behind sputum
If you have low lung volumes you increased TEE
BC:
Allows regulation of airflow, reduced WOB bc decreased O2 demand, prevents bronchoconstriction
If you have really breathless pt. you would increase BC
FET/Huffs:
Uses equal pressure point (EPP) to dynamically collapse airways to create turbulent airflow which then creates a shearing force which pushes sputum towards the main bronchus. Using different lung volumes to target different areas of the lung ie. EPP around the level of the trachea at high lung volumes and peripherally at low lung volumes
Cough:
At end to clear sputum/actually evacuate
What are precautions to ACBT
Cognitively impaired
Bronchospasm
Pt. in severe pain you’re making them force air out so you don’t want to make it any more painful than it already is
What are contrain- dications to ACBT
None is the dosage is adapted to suit the specific patient
i.e. no excessive TEE and FET in a SOB pt.
What are modifications to ACBT
If patient SOB/increased WOB increase Breathing control, if large amounts of secretions use repetitions of FET, adjust to the patient presentation
How would you teach ACBT
- Set patient up in sitting with nice posture with you next to them facing away from their mouth. Instruct them to sit with palms up
- Set up specimen cup, huffing tube and tissue
- Perform TEE with hands basally on pt.
- Perform 30s BC if too apical ask them to keep upper chest quiet
- Perform 2 x huff
- Repeat until no more crackles or patient is too fatigued
Cough vs Huff
Cough:
Only clears down to 7/8th generation of airway
Generates ++ intrathoracic pressure (300mmHg), deep inspiration and requires closed glottis
Can collapse airways distal to area of compression
Can cause bronchial instability with long term use
Good for healthy individuals to clear secretions from large airways
Huff:
Mobilises secretions from peripheral airways with low lung volumes
Opens glottis
Different lung volumes for different airway locations
Less likely to cause collapse
Best used in chronic conditions who are unable to close glottis and generate increased intrathoracic pressure
PEF must still be 10% > PIF
What is Autogenic Drainage
Gentle breathing at different volumes to loosen, mobilise and clear secretions
Using the same TV breath within different parts of the vital capacity
Performed in supine or sitting with exhalation through NOSE
Takes patience and significant effort from patient
What are the 3 phases of AD
Unstick collect evacuate
What are the physiological effects and mechanism of AD
Slow inspiration with inspiratory pause allows for homogenous filling of airways allows time for air to get behind secretions
PIFR is < PEFR therefore expiratory shearing forces mobilise sputum towards head
Utilises the alveolar recoil force to drive exhalation, therefore reducing the effort needed and force required hence reducing dynamic airway compression
No compression of airways
More gentle technique so good for patients with dynamic airway compression