Cough

• Definition of Cough• Impact• Mechanism• Approach to a patient with cough

• Complications• Treatment• Specific Disorders

What is cough?

What is cough?

A forced expulsive

maneuver, usually against

a closed glottis and which is

associated with a characteristic

soundBTS Guidelines, Thorax 2006: 61 (Suppl 1):i1 –i24.

Impact of Cough • An important airway defense mechanism• An explosive expiration

that provides a normal protective mechanism for clearing the tracheo-bronchial tree of secretions and foreign material

• Coughing helps protect the lungs against aspiration Cough pellet

Impact of Cough

• When excessive or bothersome, cough is

one of

the most common complaints motivating

patients to seek medical attention

throughout the world

• Heralds a disease or disorder

• Chronic cough is a common diagnostic and

therapeutic problem

Impact of Cough

• Discomfort from the cough itself and its

complications

• Associated with a marked deterioration in

quality

of life and interference with normal lifestyle

• Psychosocial dysfunction returns to normal with

successful treatment

Chronic Cough is a Disease• it is inappropriate to minimize a

patient's complaint of chronic cough and/or advise him/her to "live with it" since chronic cough is associated with adverse effects on his/her quality of life and it can be successfully treated in most patients who adhere to treatment

Arch Intern Med. 1998;158:1657-1661

Magnitude of the Problem• ? Cost of treating chronic cough

• IMS, 2004:

Sales of expectorants P 2.5 B

Sales of antitussives P 193.7 M

Sales of nasal decongestants P 1.7 B

Sales for Ascof P 38.2 M

• Population-Based Prevalence?

Foreign studies: 3 to 40%

Magnitude of the Problem• 1989 Rural Survey (Victoria, Laguna): 10%

chronic bronchitis

• 1991 Urban Survey (Paco, Manila): 24.6% had

“cough which was chronic or present at time of

interview”

• 2002 3 Urban Cities, young patients: 13% had

cough persisting > 2 weeks

• Chronic cough is a common problem among

Filipinos

Impact of Cough • An important factor in the

spread of infection

Mechanism of Cough

One can voluntarilyinhibit himself from coughing.A.TrueB. False

Mechanism of Cough: Initiation

• Voluntary• Reflexive

Cough phases1. Inspiratory2. Compressive3. Expulsive (Expiratory or

Explosive)- 1st cough sound heard4. Recovery

Mechanism of Cough: Reflex Pathway

McCool, F. D. Chest 2006;129:48S-53S

Flow and Subglottic Pressures During The Phases of Cough

Which phase is not critical to effective coughing?

A. Glottic closureB. Compressive C. Expiratory

McCool, F. D. Chest 2006;129:48S-53S

Irritant Triggers• Exogenous

Source Smoke, dust,

fumes, foreign bodies

• Endogenous Source

upper airway mucus, gastric contents

Mechanism of Cough: Reflex Pathway

Cough: involves a complex reflex arc that begins with irritation of a receptor

Cough Center (integrated in the

medulla oblongata)

Afferent Limb and Receptors (RARs, C fibers) Effectors

/ Superior Laryngeal

/ Recurrent Laryngeal

Approach to the Patient with Cough

Duration of Cough Estimating the duration of cough is crucial in

narrowing the list of etiologies ACCP/ ERS Consensus Guidelines (in contrast to

Harrison’s)• Acute Cough : < 3 weeks• Sub-Acute Cough: lasting 3 – 8 wks• Chronic Cough: > 8 wks

Chest 2006; 129:222S–231S.Eur Respir J 2004;24:481–92.

Any disorder

resulting in

inflammation,

constriction,

infiltration or

compression of the

upper or lower

airways and the

lung parenchyma

can be associated

with cough

Etiology of Cough

• Systematic evaluation of the afferent limb of the cough reflex

• Detailed history to obtain valuable clues, with attention to associated symptoms and includes occupational Hx and environmental exposure

• Thorough PE, including ENT examination

• Targeted laboratory examination; at least a CXR for patients with chronic cough

Anatomic Diagnostic Protocol

• Narrows DDX to specific ENT, pulmonary and extra-pulmonary causes

• Provides recommendations for targeted and successful therapy

• Standard of evaluation and management since 1981

• Adapted by ACCP Consensus Panel in 1998 and in 2006

Anatomic Diagnostic Protocol

• Chest Radiograph Can identify the presence of chest wall,

pleural, lung parenchymal and

mediastinal lesions or abnormalities

Laboratory Work Up of Cough

Chronic CoughNonsmoking Adults

Not on ACEINormal/ Near Normal CXR

Think PNDS, Asthma and/or GERD:

“The Pathogenic Triad of Chronic Cough”

Palombini, et. al., Chest 116: 279-84, 1999

• Sputum Analysis gross and microscopic examination purulent: chronic bronchitis, bronchiectasis,

pneumonia or lung abscess do G/S, C/S

blood in the sputum: rule out endobronchial

tumor eosinophilia: asthma or nonasthmatic

eosinophilic bronchitis (NAEB) AFB smears: initial lab recommended for a

Filipino with > 2wks cough, esp. if with constitutional Sx’s

Laboratory Work Up of Cough

• Paranasal/Sinus X-Ray Series/ Screening CT

Scan of the Sinuses Upper airway cough syndrome (UACS)

• 24-hour Esophageal pH monitoring Gastroesophageal Reflux Disease (GERD)

• Bronchoprovocation Test Cough-Variant Asthma

• Pulmonary Function Test/ Spirometry Differentiate Restrictive and Obstructive DOs Detect Reversible versus Non-reversible Airflow

Obstruction

Specialized Laboratory Studies To Work Up Cough

•Fibreoptic Bronchoscopy Endobronchial tumors

• High-resolution CT Scan of the Chest Chest tumors, interstitial lung diseases

• 2-D Echocardiography with or without Doppler

Studies Congestive heart failure

Specialized Laboratory Studies To Work Up Cough

• The most important first step is to decidewhether the acute cough is potentially a reflection of a serious illness, or, as is usually the case, a manifestation of a non-life-threatening, transient condition• Possible causes:

URTI, including the Common Cold – most common Lower respiratory tract infection/ Pneumonia Exacerbation of a pre-existing condition e.g.,

COPD, bronchiectasis, allergic rhinitis

Pulmonary embolus Congestive heart failure

Approach to Acute Cough

Chest 2006; 129:222S–231S

• The first step is to determine whether or not the

cough has followed an obvious preceding respiratory infection

• If the subacute cough does not appear to be postinfectious in nature, it should be evaluated and managed as if it were a chronic cough

• If post-infectious, consider: Post-Infectious Cough with BHR Atypical causes of RTI/ pneumonia including

Pertussis, PTB, atypical pneumonia, parasitic

Exacerbation of a pre-existing condition

Approach to Sub-Acute Cough

Chest 2006; 129:222S–231S.

Chronic Cough

Stop ACEICough gone

Cough persistsChest radiograph

Normal Abnormal

Avoid irritantSputum cytology, HRCT scan, modified BaE, bronchoscopy, cardiac studies

Cough gone Cough persists

Treat accordinglyEvaluate for three most common conditions singly in the following order, or in combination:1. PNDS 2. Asthma 3. GERD

Cough gone

Cough goneCough persists

Cough persists

Evaluate for uncommon conditions

Sputum tests, HRCT scan, modified BaE, bronchoscopy, cardiac studies

Cough persistsCough gone

Reconsider adequacy of treatment regimens before considering habit or psychogenic cough

Consider postinfectious cough

Hx / PE ACEI

Order accordingly to likely clinical possibility

Abnormality may not be related to cough

Approach to Chronic Cough

• The starting point is the medical history, physical examination, and CXR via the anatomic diagnostic protocol

• Rule out ACEI-induced cough early on in the work up

• Avoid identifiable irritants, when possible• Evaluate and treat for the 3 most common

conditions, singly or in combination: Postnasal Drip Syndrome or UACS Cough-Variant Asthma GERD

Approach to Chronic Cough

Chest 2006; 129:222S–231S.

International Validation of Anatomic Diagnostic Protocol

• Cause successfully determined in 88-100%• Successful therapy in 82 to 98%• Asthma, PNDS, GERD in 85 to 94%• Single cause in 38-82%; 2 or more in 18-62%• 3 Asian studies• Validated in the Philippines at the PGH

Identification of the Causes of Cough > 3 Weeks in Adult Filipinos

Figure 3. Frequency Distribution of the Causes of Chronic CoughAmong the Evaluable Patients.

33.3

30.4

20.3

15.2

10.1

6.85.1

3.8 3.8 3.0

0.81.7

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

Causes of Chronic Cough

Asth

ma P

ND

S PT

B PostIn

fx

Cough

Bro

nch

iecta

sis P

neum

on

ia G

ER

D AC

EI-

indu

ced

Pulm

onary

C

A CH

F Oth

er

sCO

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/ C

BDavid-Wang AS, Balgos A, Roa Jr. CC, Dantes R, et. al., Chest 130: 199S, 2006.

Figure 4. Number of Causes Identified Per Patient

2.5

29.5

67.5

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

1 2 3

Number of Causes

%

• Most frequent 2 combination: Asthma and PNDS in 40%• Most frequent 3 combination: Asthma, PNDS, GERD in 33%

Identification of the Causes of Cough > 3 Weeks in Adult Filipinos

David-Wang AS, Balgos A, Roa Jr. CC, Dantes R, et. al., Chest 130: 199S, 2006.

• Sputum AFB smears must be ordered early on esp. if the clinical probability of PTB is high• Chest radiographs can narrow the differential diagnosis and thus must also be ordered earlier whenever possible• Empiric drug therapy for asthma, PNDS and GERD can be tried if the clinical probability is high

Local Modifications to the Chronic Cough

Algorithm

49.1%

24.3%

6.5%

9.6%

No action taken Self-medication Gov't Centers Private MDs

Health Seeking Behavior Among TB Symptomatics (NPS 1997)

Treatment of Cough

Treatment of Cough• Specific Therapy• Symptomatic or

Nonspecific Therapy

Specific Cough Therapy• Definitive treatment: treat the

underlying cause!

• elimination of the inciting agent,

whenever possible

Non-Specific Cough Therapy• when the cause is unknown or specific Rx is not possible• the cough performs no useful function or causes marked discomfort

1. Antitussive or Cough

Suppressant• drugs that increase the latency or

threshold

of the cough center, e.g., codeine,

dextromethorphan

• drugs that affect the afferent limb of

the

cough reflex, e.g., levodropropizine

• for irritative, nonproductive cough

Non-Specific Cough Therapy

2. Protussive• enhance cough effectiveness by

promoting the clearance of airway secretions and loosen mucus

• indicated in cystic fibrosis, bronchiectasis,

pneumonia and postoperative atelectasis

• pharmacologic agents e.g., nebulized saline solution, erdosteine

Non-Specific Cough Therapy

2. Protussive • mechanical aids- for patients with neuromuscular or neurologic diseases

Non-Specific Cough Therapy

Cough assist machine

• 35 y.o. businessman• Indian origin• Non-smoker • 3 weeks of non-productive cough • No other associated Sx’s• No co-morbidities• Nasal, posterior pharyngeal, chest, heart and lung examination was unremarkable.

What will be your next step for this patient?

1. Perform a more thorough physical exam

2. Do a CXR3. Treat empirically for PNDS4. Treat empirically for asthma5. Treat empirically for GERD

Cause of cough for this patient…

• Hair in the ear canal touching the tympanic membrane

• Cough resolved with hair plucking

• formerly Postnasal Drip Syndrome• related to upper airway conditions • unclear whether cough mechanism is due to PND, direct irritation or inflammation of cough receptors

• includes allergic/ perennial nonallergic/vasomotor / postinfectious/ occupational rhinitis, allergic/ bacterial sinusitis, etc.

•nasal congestion or discharge, PND, throat clearing/ itchiness, facial pain, hoarseness; “cobblestone” post. pharyngeal mucosa

Upper Airway Cough Syndrome

Chest 2006; 129:1S–23S.

• In patients in whom the cause of the UACS-induced cough is apparent, specific therapy directed at this condition should be instituted (Grade of Recommendation: B)

• Empiric therapy for UACS should be instituted for patients with chronic cough prior to extensive testing (Grade of Recommendation: B) with a first-generation antihistamine/ decongestant (Grade of Recommendation: C)

Upper Airway Cough Syndrome

Chest 2006; 129:1S–23S.

• Cough is the main or predominant complaint• = Mild Persistent Asthma (GINA Guidelines)• Empiric therapy if clinical suspicion is high (Grade A)

• Bronchoprovocation testing if PE and spirometry are nondiagnostic and if it is available (Grade A)

• Inhaled steroids and inhaled bronchodilators (Gr. A)

• 1-2 weeks short course systemic steroid for those with severe and/or refractory cough (Grade B)

Cough Variant Asthma

Chest 2006; 129:1S–23S.

intermittent/ episodic nocturnal cough identifiable triggers family history of asthma and/or atopy presence of wheezing relief with bronchodilators resolves with inhaled steroids

Clinical Findings Suggestive of Cough Variant Asthma

•Heartburn, regurgitation, ‘acidic’ taste,

dysphagia, epigastric pain, hoarseness

•Worsens when lying supine•Aggravated by intake of coffee/ tea, carbonated drinks, citrus fruits

•Cough may be the only manifestation

GERD

Chest 2006; 129:1S–23S.

• Empiric therapy if clinical suspicion is high (Grade B)

• 24-hour esophageal pH-monitoring test is the most sensitive and specific test and should be done if cough does not improve with medical therapy or to assist in determining if Rx needs to be intensified (Grade B)

•Anti-reflux therapy: proton pump inhibitors (as 1st line or if H2-blockers are ineffective), lifestyle modification; add prokinetic therapy if PPIs alone are ineffective (Grade B)

GERD

Chest 2006; 129:1S–23S.

• Airway eosinophilia but N spirometry, no variable airflow obstruction and no BHR

• Consider occupation-related cause• First line drug: Inhaled steroids or short-course oral steroids

Nonasthmatic Eosinophilic Bronchitis

(NAEB)

• Cough that has been present for at least 3 weeks following symptoms of an acute respiratory infection

• Includes post viral BHR• Trial of inhaled ipratropium (Grade B)• Use of Inhaled ICS if inhaled ipratropium ineffective (Grade E/B)

• Central acting antitussives such as codeine or dextromethorphan should be considered when other measures fail (Grade E/B)

Post-Infectious Cough

• Consider other diagnoses if cough > 8 weeks

• Consider Pertussis if cough > 2 weeks, in paroxysms, with posttussive vomiting or inspiratory whooping (even in adults); treat with macrolide

Post-Infectious Cough

• Accumulation of protussive mediators such as bradykinins and substance P in the resp. tract with ACEI; bradykinins stimulate production of prostaglandins

• Dry cough, scratchy throat•In order to determine that ACEI is the cause, therapy should be discontinued regardless of the temporal relaton between the onset of cough and the initiation of ACEI (Grade B)

• Cough usually resolves within 1 to 4 weeks of cessation, up to 3 months

ACEI-Induced Cough

• A diagnosis of exclusion• After an extensive evaluation has been performed

that includes ruling out tic and neurologicdisorders (e.g., Tourette syndrome) andother uncommon causes

• Improves with specific therapy such as behavior

modification or psychiatric therapy

Habit or Psychogenic Cough