Bronchial Diseases Flashcards
(57 cards)
What is the role of the cough reflex?
Protective mechanism
- Assists mucociliary clearance
- Expels inhaled particulate material
- Protects against inhaling particles/irritants
Where are mechanoreceptors and chemoreceptors located?
Mechanoreceptors – larger airways
Chemoreceptors – medium airways
Where are cough receptors most numerous?
Larynx > Trachea > Bifurcation > Bronchi
None in bronchioles or alveoli
What are the 3 main causes of a cough?
Compression of mainstem lobar bronchi
Stimulation of cough receptors
Excessive mucus/fluid/inflammation
What are the DDx for compression of mainstem lobar bronchi -> cough?
- Left atrial enlargement
- Tracheobronchial / Bronchial Lymph node enlargement
- Neoplasia
What are the DDx for stimulation of cough receptors?
Laryngeal disorders
Tracheal disorders
Bronchial disorders
What are the DDx for excessive mucus / fluid / inflammation -> cough?
(usually soft / moist / ineffectual cough)
- Pneumonia
- Bronchopneumonia
- Pulmonary oedema
Describe the presentation of a cough when caused by cardiac disease
- Normal/increased HR
- Regular sinus rhythm, sinus tachycardia or arrythmias
- Occur mainly at night, when resting/sleeping
- Usually a heart murmur present
- Diastolic gallops possible
Describe the presentation of a cough when caused by respiratory disease
- Normal or decreased HR
- Sinus arrythmia
- Occur mainly when excited/exerted
- No murmur
- No diastolic gallops
What information would you need to gather from the history of a coughing patient?
- Environment
- Worming history
- Travel history
- Recent events / illnesses / changes
- How long coughing? Onset?
- Description of the cough. When worse?
- Is the cough really a cough?
- Any change in bark?
- Does the dog sleep normally?
What information would you need to gather from the clinical exam of a coughing patient?
- Observation (respiratory rate / pattern / any dyspnoea / any spontaneous coughing)
- Listen to all lung areas during normal quiet (non-panting) respiration. Identify adventitious respiratory sounds.
- Listen to and palpate URT
- Percussion
- Thoracic compressibility (cats)
- Attempt to induce a cough – auscultate following cough
Cats rarely cough due to what kind of disease?
Cardiac
If the animal is in left sided heart failure, the following triad of signs will be present on thoracic radiographs…?
- LA enlargement
- Pulmonary venous distension
- Pulmonary infiltrate (usually predominantly perihilar)
What is seen on a radiograph which indicates bronchial wall thickening?
‘Doughnuts’ and ‘Tramlines’
What are the characteristic changes seen in the airways due to chronic bronchitis?
- Excessive mucus production
- Increased goblet cell numbers
- Hyperplasia or submucosal glands
- Damage to cilia
- Loss of ciliated epithelium
- Squamous metaplasia of mucosa
- Secondary infections
How does chronic bronchitis present?
- Typically small breed / toy breed dogs
- Chronic cough with attempts at production
- Worse on excitement
Describe the prognosis of chronic bronchitis
Prognosis is guarded, since most mucosal changes are not reversible
What is the goal of treatment for chronic bronchitis?
To manage the condition, not to cure
What is the definition of chronic bronchitis?
Coughing for more than 2 of the last 12 months
How is diagnosis of chronic bronchitis confirmed?
Bronchoscopy and bronchoalveolar lavage fluid cytology (+/- bacteriology).
How would a patient with chronic bronchitis present on bronchoscopy?
- Loss of the normal appearance of a glistening mucosal surface
- Thickened mucosa: can be irregular with a cobble-stone appearance
- Excess mucus
Describe the typical cytology of a patient with chronic bronchitis
Mixed inflammatory infiltrate
- pulmonary alveolar macrophages
- neutrophils
- occasional eosinophil
- plasma cells
Describe the general management tips for chronic bronchitis
- Reduce weight if obese
- Avoid stimulating a cough (as vicious cycle): use harness rather than collar / lead
- Avoid irritants e.g. smoky environment
- Keep airways moist
Bronchomalacia is another term for?
Bronchial collapse