Lecture 14: Cough Flashcards
What is the tussive reflex?
Stimulation of sensory nerves
By irritant, e.g. particulate, or obstructive, e.g. mucous
Nerves located in epithelium of pharynx, larynx, trachea and bronchi (carina of trachea = greatest concentration)
Cough centre in medulla
Expiratory muscles contract
What are the expiratory muscles used in coughing?
Internal intercostals, rectus abdominus,
external and internal obliques, transversus abdominus
Why is the tussive reflex necessary?
Prevents aspiration
Supplements clearance mechanisms (muco-ciliary escalator) when baseline overwhelmed or
inadequate
What is the difference between an acute, a persistent and a chronic cough?
Acute: <2 weeks
Persistent: 2-8 weeks
Chronic: >8 weeks
What features of sputum are important?
Volume
Colour
Consistency
Presence of blood
What are the different kinds of haemoptysis?
Bright red blood (e.g. seen in pulmonary infarction (rarer), but also in rupture of superficial
capillaries of pharynx)
Rusty colour (e.g. seen in pneumonia)
Pink and frothy (e.g. seen in heart failure or other causes of pulmonary oedema)
What are the common causes of haemoptysis?
Bronchial carcinoma
Acute infection
TB
Pulmonary infarction
What are the occasional causes of haemoptysis?
Trauma
Vascular abnormalities (e.g. AV malformations)
Bleeding disorders (inc. iatrogenic!)
What are the rare causes of haemoptysis?
Associated with SLE
Aspergillosis
Goodpasture’s syndrome
What are the nasal and naso-pharyngeal considerations?
Rhinosinusitis: acute and chronic, postnasal drip
Cough, postnasal drip, need to clear throat, tickle, nasal congestion, nasal
discharge, hoarseness
Antihistamines,
intra-nasal
corticosteroids, limited use of some decongestants
Also viral upper respiratory tract infections
What are the tracheobronchial considerations?
Asthma COPD Bronchiectasis Cancer Infection
How do you measure pack years?
20/day for 20
years = 20 pack years
10/day for 20 years = 10 pack years
What is bronchiectasis?
Scarring from previous infection or as part of other conditions (e.g. cystic fibrosis)
Dilation of smaller airways (bronchioles) forming potential space for mucous pooling,
stagnation and infection
Lower threshold for antibiotics, and often longer course
Consideration of ‘colonisation’ with specific pathogens (e.g. pseudomonas)
What % of asthmatics report cough at least once a week?
40%
How does GORD cause cough?
Cough triggered by cough receptors in the oesophagus (micro- or macro-aspiration of stomach contents, vagally mediated reflex mechanisms)
Diagnosis confirmed if resolves with specific anti-GORD therapy:
– Conservative measures
– Therapy (proton pump inhibitors are more rapidly effective than H2 antagonists)
