8. Cough

Question 1

What are the classifications of cough based on duration?

Answer 1

Acute cough is less than 3 weeks, subacute cough is 3-8 weeks, and chronic cough is more than 8 weeks.

Question 2

What is the difference between productive and dry cough?

Answer 2

Productive cough involves sputum expectoration, while dry cough does not.

Question 3

What is a cough?

Answer 3

Cough is characterized by short and deep inspiration followed by forced expiration with a closed epiglottis.

Question 4

What is the cough reflex arc?

Answer 4

The cough reflex arc involves
1. irritation of cough receptors in the large airways, auditory canal, and pleura,
2. transmission along the afferent pathway via the internal laryngeal nerve of the vagus nerve (CN X) to the cough center in the medulla and pons,
3. generation of efferent signal in the medulla and initiation of cough via the vagus, phrenic, and spinal motor nerves.

Question 5

What percentage of airway infections are caused by viral pathogens?

Answer 5

85% of airway infections are caused by viral pathogens such as Influenza, Adenovirus, SARS-CoV2, and RSV.

Question 6

What are the common bacterial pathogens that can cause cough?

Answer 6

Common bacterial pathogens that can cause cough include Streptococcus pneumoniae, Hemophilus influenzae, and Moraxella catarrhalis.

Question 7

What are atypical bacteria, and what antibiotics are required to treat them?

Answer 7

Atypical bacteria such as Chlamydia pneumoniae, Mycoplasma pneumoniae, and Legionella pneumophila are intracellular pathogens that require macrolide antibiotics to treat.

Question 8

What is a treatment possibility for atypical bacteria?

Answer 8

Macrolide antibiotics.

Question 9

What are the causes of productive cough?

Answer 9

The causes of productive cough include
- acute and chronic bronchitis,
- tracheitis,
- pneumonia,
- lung tumor,
- bronchiectasis,
- tuberculosis.

Question 10

What are the causes of acute dry cough?

Answer 10

The causes of dry cough include
- PNDS,
- acute pharyngitis/laryngitis,
- atypical pneumonia,
- pleuritis,
- asthma,
- embolism,
- irritation of auditory canal,
- lung tumor,
- foreign body.

Question 11

What is the difference between acute and chronic bronchitis?

Answer 11

Acute bronchitis is a short-term inflammation of the bronchi, while chronic bronchitis is a long-term inflammation of the bronchi that is a type of COPD.

Question 12

What is the difference between acute and chronic pharyngitis/laryngitis?

Answer 12

Acute pharyngitis/laryngitis is a viral infection that causes a dry cough, while chronic pharyngitis/laryngitis is a long-term inflammation of the pharynx/larynx that causes a productive cough.

Question 13

What is the difference between acute and atypical pneumonia?

Answer 13

Acute pneumonia is caused by bacteria and produces yellow/green sputum, while atypical pneumonia (walking pneumonia) is caused by atypical bacteria and produces a repeated cough and subfebrility.

Question 14

What is bronchiectasis?

Answer 14

Bronchiectasis is a condition where the bronchial tubes are permanently damaged, widened, and thickened, leading to a chronic productive cough.

Question 15

What is the difference between a centrally located lung tumor and a peripherally located lung tumor?

Answer 15

A centrally located lung tumor causes a productive cough that is smelly, while a peripherally located lung tumor causes a dry cough.

Question 16

What is the treatment for a foreign body in the respiratory tract?

Answer 16

The treatment for a foreign body in the respiratory tract is bronchoscopy to remove the foreign body, and if nothing is seen, a bronchoalveolar lavage may be done.

Question 17

What are some possible causes of chronic dry cough?

Answer 17

Emphysema, cardiac disease, reflux, pulmonary fibrosis, ACE inhibitors

Question 18

What is the typical feature of pertussis infection?

Answer 18

Inspiratory whoop.

Question 19

What are some precipitating factors of cough?

Answer 19

Cold air, allergies, toxic inhalation, exercise, supine position (GERD, CHF), daytime or nighttime worsening of symptoms.

Question 20

What are some symptoms of possible causes of cough?

Answer 20

• Runny nose + sore throat (URI, postnasal drip),
• fever chills + pleuritic chest pain (pneumonia),
• night sweats + weight loss (TB, tumor),
• heartburn (GERD)
• dysphagia / chocking (aspiration)

Question 21

What should be asked about in the past medical history of a patient with a chronic cough?

Answer 21

Exposure (irritants, tobacco smoke, infectious contacts) and travel history (endemic areas, at-risk activities).

Question 22

What is the recommended testing for all investigation protocols of a cough?

Answer 22

Chest X-ray.

Question 23

What testing is indicated for suspicion of lung cancer or foreign body aspiration?

Answer 23

Chest CT and bronchoscopy.

Question 24

What testing is recommended for infections such as pertussis or TB?

Answer 24

Sputum culture.

Question 25

What is the first step in therapy for cough?

Answer 25

• Identifying and treating the underlying cause
• eliminating any known modifiable triggers such as smoking cessation or medications.

Question 26

What is the mechanism of action of central cough suppressants?

Answer 26

Central cough suppressants suppress the cough reflex arc at the level of the CNS.

Question 27

What are the drugs used for central cough suppression?

Answer 27

• Codeine, hydrocodone (opioid alkaloids)
• Non opioids : Butamirate and pentoxyverine interfere with neural pathways associated with the cough reflex arc.

Question 28

What is the mechanism of action of expectorants?

Answer 28

Expectorants increase bronchial fluid to promote excretion of mucus without suppressing cough.

Question 29

What is the mechanism of action of mucolytics?

Answer 29

Mucolytics liquefy mucus by reducing disulfide bonds of mucoproteins.

Question 30

What is the mechanism of action of secretolytics?

Answer 30

Secretolytics break up mucus secretions.

Question 31

What is the local drug used for anesthesia of the receptors before bronchoscopy?

Answer 31

Lidocaine is used for anesthesia of the receptors before bronchoscopy to reduce sensitivity.

Question 32

What are some examples of secretolytics?

Answer 32

Essential oils, iodine salts, ammonium salts.

Question 33

What are some examples of surface coatings that can be used to reduce cough sensitivity?

Answer 33

Honey, sweets.

Question 34

What are some mucolytics ?

Answer 34

Acetylcysteine, bromhexine