CRP Flashcards
What are the key principles of sputum retention?
- flow
- pressure
- volume
what are the mechanics behind flow, pressure and volume?
flow = speed of a gas or fluid
pressure = force of a gas or fluid
volume = measurement of size of gas or fluid
what is airway flow affected by?
pressure and resistance as it moves from a positive to negative pressure gradient
describe airway mechanics and fluid dynamics
Lumen of airways are very important = Poiseuille’s law
Compliance of the lung and thorax
= Pressure-volume curves and elasticity
Air flow velocity consideration
= Bernoulli’s principle
Fluid mechanics in secretion movement
= Two phase gas-liquid flow
Ability to generate pressures
= Muscle activation of diaphragm, abdominals
what is bernoulli’s principle
Bernoulli’s principle allows increased airflow velocity in the smaller airways. In the alveoli, this velocity is spread out but if airways become occluded, increased turbulence and chance of collapse
what is Poiseuille’s principle
Poiseuille’s principle is the basis for PEP and why people will find it difficult to clear thick secretions. As any obstruction will cause and increased resistance 4 times the radius of the tube!
what is the cilia beat frequency per second?
12-14
what can effect the cilia
pollutants, tobacco smoke, anaesthetic agents and infections
how do you overcome mucus sticking to airway walls and get movement of secretions?
peak expiratory flow rate (PEFR) has to be greater than the peak inspiratory flow rate (PIER)
what causes the airway to narrow and fill with mucus?
- asthma
- COPD
- bronchiectasis
- CF
in what illness’ are pressures to move air into the lung are greater when lungs are hyperextended?
- emphysema
- COPD
- IPF
what illness’ have no muscle activation which means volumes are harder to maintain?
- neuromuscular disease
- chest wall diseases
what are the 3 requirements for normal musco-ciliary clearance?
- effective cough
- expiratory airflow
- normal MCT system and environment
what is a mucociliary tract system (MCT)?
carries debris as far as the pharynx, where the fluid and mucus is then swallowed and the debris eliminated by the digestive system
name some factors that can lead to sputum retention?
- pathology
-pain - bronchospasm
- ineffective cough
- dehydration
- changes to MCT
what are the symptoms of sputum retention?
- fever
- malaise
- changes in sputum
- stress urinanry incontinence
- chest pain
- dysponea - increased WOB
- decreased functional activity
what are the signs of sputum retention?
- cough
- auscultation
- palpation
- changes to RR and pattern
- bacterial growth
- radiographic changes
- ABGs sats
- LFT
what is bronchiectasis?
- permanent abnormal dilation of one or more bronchi
- caused by damage to the airways due to severe lower respiratory tract infections related to pneumonia, whooping cough or measles.
describe the process of bronchiectasis in terms of pathophysiology?
- inflammation to the bronchi
- destruction of bronchial walls
- collapse of parenchyma
- bronchi dilate
what are the clinical features of bronchiectasis?
- dyspnoea
- productive cough
- increasing sputum
- wheezing
- chronic hypoxia
- pulmonary hypertension
name some airway clearance techniques
- PEP
- ACBT
- postural drainage
- positive pressure
