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CVPR: Pulmonary > Cough > Flashcards

Flashcards in Cough Deck (20)
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1

Fxn of cough

Cough defends the body by clearing pathogens, particulates, foreign bodies, and accumulated secretions from the lung airways, larynx and pharynx.   

2

Afferent pathway of cough

  • 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

Phases of efferent pathway of cough

1. Inspiratory Phase: inhalation ends before closure of the glottis

2. Compressive Phase: thoracic and abdominal muscles contract against a fixed diaphragm (modified Valsalva maneuver); intrathoracic pressure increases (≤ 300 mm Hg)

3. Expiratory Phase: glottis opens; air is rapidly (≤ 500 miles/hr!) expelled

4. Relaxation Phase: chest wall and abdominal muscles relax

4

Acute cough definition + common causes

  • 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

Subacute cough defintion + possible causes

  • cough lasting 3-8 weeks
  • postinfectious cough = follows an obvious preceding URI/LRI
  • possibly PNA or bacterial bronchitis

6

Chronic cough definition + common causes

  • 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

UACS: mechanism

  • "post-nasal drip syndrome"
  • secretions from nose/paranasal sinus ==> stimulation of upper airway cough receptors OR
  • direct irritation/inflammation of receptors

8

UACS: signs & symptoms

  • 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

UACS: dx and tx


  • first generation anti-histamine/decongestant combination medication for > 2 weeks 

  • Improvement or resolution of cough is consistent with UACS.  
     

10

Asthma: mechanism

  • =chronic, inflammatory airway disorder w/airflow obstruction
  • stimulation of cough receptors by inflammatory mediators, mucus, bronchoconstrictions

11

Asthma: signs & symptoms

  • symptoms
    • classic = episodes of wheezing, dyspnea, cough
    • cough-variant = cough is only symptom
  • signs
    • bilateral, polyphonic wheezes (not always present)

12

Asthma: dx tests + tx

  • 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

GERD: mechanism

  • backflow of stomach contents into esophagus
  • stimulation of receptors via irritation @:
    • upper respiratory tract
    • lower respiratory tract (aspiration)
    • esophageal-bronchial cough reflex

14

GERD: signs & symptoms

  • symptoms
    • cough (w/ or w/out phlegm)
    • GI symptoms (heartburn, regurg) may be absent

15

GERD: dx tests & tx

  • 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.



       

16

NAEB: characteristics & mechanism

  • eosinophilic airway inflammation, similar to that seen in asthma, but without variable airflow limitation or airway hyperresponsiveness
  • stimulation of lower airway cough receptors by inflammatory mediators

17

NAEB: signs & symptoms

  • symptoms: cough w/out wheezing or dyspnea
  • signs: no wheezes

18

NAEB: dx test and tx

  • PFTs = normal
  • induced sputum analysis ==> increase in eosinophils
  • tx: inhaled corticosteroid for >4 wks

19

Antibiotics in acute cough

  • use in case of bacterial infection e.g.:
    • bacterial pneumonia
    • bacterial bronchitis

20

Common causes of cough in children

  • acute = viral URI
  • chronic = asthma, sinusitis, GERD
    • underlying lung disease
    • second-hand smoke