Cough: Clinical Perspectives and Therapy Flashcards
Describe the classic cough patient
Female, ≥50
Hypersensitive to aerosols
What are the aims of treating cough symptoms
↓Intensity
↓Frequency
What are the top three causes of cough
GORD
Rhinosinusitis (postnasal drip)
Asthma
Infection, COPD, Drugs, ILD
What causes the cough in ILD?
Traction of tissue irritates vagal nerve endings
What is the mechanism for cough in GORD
Vagus nerve innervation by acid in lower oesophagus
Acid in the laryngeal area which stimulates superior laryngeal nerves
Microaspirations
Presenting complaints of GORD
Early morning cough
Indigestion
Waterbrash
Cough
What are some diagnositc investigations for GORD
Oesophageal Impedence (paried channels down the oesophagus, records any break of the current and pH)
Manometry (measures pressures in oesophagus)
What are the treatments for GORD
- PPI + Anti-histamines
- Alginates (Gaviscon - coats oesophagus)
- Motility agents (to keep acid down)
- Nissen’s fundoplication (imitates sphincter) - not many studies at the moment for GORD cough
PPI is first line hoever, Cochrane review showed it was ineffective at ↓cough severity
Name tools used to assess cough severity
Leicester Cough Questionnaire
Visual cough Scale
What are the mechanisms of cough in asthma (3)
- Inflammation -> Nerve ending stimulation
- Constrictor stimuli -> Bronchoconstriction induced cough
- Mucus -> clearnce and stimlui of nerve endings?
Apart from asthma, what are some other eosinophilic airway diseases?
Cogh Variant Asthma
Atopic Cough
Eosinophilic Bronchitis
Why might an asthmatic patient still have a cough even though on treatment?
Poor Compliance
Other cough-disease (post-nasal drip, GORD)
Name some uncommon causes of cough
OSA
Chronic tonsillar enlargement
Arnold’s Reflex
Tracheobronchopathia osteochondroplastica
Drugs (Indacaterol B2 agonist, 20% cough SE)
What is the mechanism of cough in patients with obstructive sleep apnoa
- Airway trauma sa a result of snoring and collapsed larynx.
- Airway inflammation
- Irritation of nerve endings
- Apnoea
- ↑Effort to ventilate
- ↑Trans-diaphragmatic pressure
- ↓sphincter tone
- Cough
Tracheobronchopathia osteochodroplastica can cause cough. What is this
Benign, submucosal nodules growing from submucosal layer in airways
Describe the manifestation of cough from Anrold’s reflex
Auricular branch of the vagus nerve gets stimulated by ear wax
Induces cough through vagus nerve
Good hygeine will stop this
Charactersitics of Holmes-Adie Syndrome and link with cough
Aniscoria (unequal eye pulis, ankle tendon areflexia)
Loss of myelination of lung afferents -> ↑hypersensitivity of secondary neurons in the nucleus solitarius
40% of patients have idiopathic cough. What are some reasons for the increased cough (mechanisms of cough) in this context (5)
- ↑Airway Nerve Sensitivity
- ↑Capsaicin sensitivity and C-fibre activation
- ↑Density of nerve fibres (↑CGRP nerves)
- ↑TRPV1 receptors
- ↑Sensitivity of laryngeal glotic closure reflex
- General vocal cord dysfunction
- Airway Inflammation
- Mediators (histamine, PGE2, LTs)
- Cells (neutrophils)
- Goblet Cell hyperplasia
- Cause or consequence
Current treatments for idiopathic cough
Morphine - reduces cough severity, central mechanism of action, risk of SE and dependence
Codeine - chronic COPD cough - not effective
Novel therapy for anti-tussives
P2X3 receptor ?antagonist
Promising data in animal and in vitro modls - untested in humans
Effect of theobromine on cough
Reduces sensitivity to capsaicin (theobromine leads to more concentrations of capsaicin to induce cough)
What is the mechanism of action of theobromine?
Adenosine 1 receptor antagonist and PDE inhibitor
Leads to ↑cAMP
Theobromine = theophyline = methylxanthine
What are some non-licensed therapies ofr cough
Cloves, hot ginger with honey, steam inhalation of Vick Vaporub
LAMA
Low dose Gabapentin
Low dose opiate
Mucolytics (carbocisteine)
