Breathing Flashcards
What are the applications of flexible bronchoscopy?
Therapeutic and Diagnostic
- visualisation of pathology
- sampling eg Bronchoalveolar lavage
- Difficult intubations
- Direct opening eg retrieval or stenting
Why might you pick rigid vs flexible bronchoscopy?
Rigid allows for greater suction and more instrumentation
What is Tidal Volume? and roughly what value is it?
Tidal Volume = volume in and out in one cycle
Roughly 7ml/kg ~500ml
What are inspiratory and expiratory reserve volumes?
This is the volume above and below quiet respiration and tidal volume
IRV is around 3L
ERV is around 1.3L
What is the Inspiratory Capacity?
Inspiratory Capacity = Tidal Volume + Inspiratory Reserve Volume
What is Vital Capacity?
Vital Capacity = Tidal Volume + both inspiratory and expiratory reserve volumes
What is Residual Volume?
Residual Volume = gas remaining after maximum expiration
What is Total Lung Volume?
Total Lung Volume = Vital Capacity + Residual Volume
What is Function Residual Capacity? and what increases it?
Functional residual capacity = Expiratory reserve + respiratory volume ~3L
This is increased in:
1. COPD/Asthma (obstructive)
2. PEEP eg CPAP
How do you differentiate obstructive vs restrictive lung disease
Use spirometry:
Obstructive: FEV1/FVC < 0.8
Restrictive: FEV1/FVC > 0.8
What is atelectasis?
Atelectasis is collapse (loss of gas) in any section of lung
What is absorption atelectasis?
Oxygen is absorbed more readily than nitrogen
over oxygenation causes collapse
What are the causes of post-op atelectasis?
- Increased secretions
- Pain causing reduced tidal volume
- Over oxygenation and absorption atelectasis
- Patient: High BMI, Smoking, COPD
What is Bronchiectasis?
Irreversible dilatation of the bronchi (due to infection) and impaired clearance of secretions
Presents clinically as obstructive
What are the common causes of bronchiectasis and how can they be categorised?
Congenital:
1. Cilliary Dyskinesia (Kartagener’s)
2. Cystic Fibrosis (most common)
3. Immunodeficiency (multiple infections)
Acquired:
1. Repeated acute and chronic inflammation (eg infection)
2. Obstruction (eg tumours/foreign body)
3. Others eg aspergillosis, Rheumatoid, UC