Cough Flashcards
1
Q
Fxn of cough
A
Cough defends the body by clearing pathogens, particulates, foreign bodies, and accumulated secretions from the lung airways, larynx and pharynx.
2
Q
Afferent pathway of cough
A
- vagus nerve helps initiate cough via 3 receptors
- RAR (rapidly adapting receptors) & SAR (slowly adapting stretch receptors) ==> mechanical stimulation
- C fibers ==> (noxious) chemical stimulation
3
Q
Phases of efferent pathway of cough
A
- Inspiratory Phase: inhalation ends before closure of the glottis
- Compressive Phase: thoracic and abdominal muscles contract against a fixed diaphragm (modified Valsalva maneuver); intrathoracic pressure increases (≤ 300 mm Hg)
- Expiratory Phase: glottis opens; air is rapidly (≤ 500 miles/hr!) expelled
- Relaxation Phase: chest wall and abdominal muscles relax
4
Q
Acute cough definition + common causes
A
- cough < 3weeks
- life-threatening causes:
- PNA, sever asthma/COPD exacerbation, PE, heart failure
- non-life threatening
- URI=common cold: nasal congestion, post-nasal drip, cough
- Lower respriatory infection (acute bronchitis)
- exacerbations of pre-existing conditions
- environmental/occupational exposures
5
Q
Subacute cough defintion + possible causes
A
- cough lasting 3-8 weeks
- postinfectious cough = follows an obvious preceding URI/LRI
- possibly PNA or bacterial bronchitis
6
Q
Chronic cough definition + common causes
A
- cough lasting > 8wks
- most common causes (in immunocompetient adults w/normal CXR):
- UACS = upper airway cough syndrome
- asthma
- GERD = gastroesophageal reflux disease
- NAEB = non-asthmatic eosinophilic bronchitis
- **may be caused by more than onde disease
7
Q
UACS: mechanism
A
- “post-nasal drip syndrome”
- secretions from nose/paranasal sinus ==> stimulation of upper airway cough receptors OR
- direct irritation/inflammation of receptors
8
Q
UACS: signs & symptoms
A
- Symptoms:
- “tickle” in throat
- throat-clearing, hoarseness
- nasal congestion and drainage
- cough
- Signs
- oropharyngeal mucosa = cobblestone
- mucus in nasal passages or oropharynx <== caused by nasal/sinus inflammation
9
Q
UACS: dx and tx
A
- first generation anti-histamine/decongestant combination medication for > 2 weeks
- Improvement or resolution of cough is consistent with UACS.
10
Q
Asthma: mechanism
A
- =chronic, inflammatory airway disorder w/airflow obstruction
- stimulation of cough receptors by inflammatory mediators, mucus, bronchoconstrictions
11
Q
Asthma: signs & symptoms
A
- symptoms
- classic = episodes of wheezing, dyspnea, cough
- cough-variant = cough is only symptom
- signs
- bilateral, polyphonic wheezes (not always present)
12
Q
Asthma: dx tests + tx
A
- PFTs ==> >12% increase in FEV1 after bronchodilator
- methacholine challenge
- Tx = inhaled bronchodilator + inhaled corticosteroid for > 8 weeks
- avoidance of triggers (e.g. allergens)
- some cases, oral corticosteroids
- improvement or resolution of cough confirms the diagnosis of asthma.
13
Q
GERD: mechanism
A
- backflow of stomach contents into esophagus
- stimulation of receptors via irritation @:
- upper respiratory tract
- lower respiratory tract (aspiration)
- esophageal-bronchial cough reflex
14
Q
GERD: signs & symptoms
A
- symptoms
- cough (w/ or w/out phlegm)
- GI symptoms (heartburn, regurg) may be absent
15
Q
GERD: dx tests & tx
A
- dx: 24-hour esophageal pH monitor
- tx:
- gastric acid suppression with a proton pump inhibitor (e.g. omeprazole) for ≥ 2 months
- diet and lifestyle modification
- improvement or resolution of cough confirms the diagnosis of GERD.
