Definition, Causes and Epidemiology of Bronchiectasis

• Bronchiectasis: An abnormal and permanent dilatation of bronchi, most often secondary

to an infectious process.

• It may be either focal, involving airways supplying a limited region of pulmonary

parenchyma, or diffuse, involving airways in a more widespread distribution.

• Although this definition is based on pathologic changes in the bronchi, diagnosis is often

suggested by the clinical consequences of chronic or recurrent infection in the dilated

airways and the associated secretions that pool within these airways.

Etiology and Pathogenesis

• Bronchiectasis is a consequence of inflammation and destruction of the structural

components of the bronchial wall. Infection is the usual cause of inflammation.

Infectious Causes

• Adenovirus and Influenza virus is the main viruses that cause bronchiectasis in

association with lower respiratory tract involvement.

• Virulent bacterial infections, especially with potentially necrotizing organisms such as

Staphylococcus aureus, Klebsiella, and anaerobes, remain important causes of

bronchiectasis when antibiotic treatment of pneumonia is not given or is significantly

delayed.

• Bronchiectasis has been reported in patients with HIV infection, perhaps at least partly

due to recurrent bacterial infection.

• Tuberculosis can produce bronchiectasis by a necrotizing effect on pulmonary

parenchyma and airways and indirectly as a consequence of airway obstruction from

branch stenosis or extrinsic compression by lymph nodes.

• Others causes include

Non Tuberculous mycobacteria

Mycoplasmal (rare)

Fungal infections (rare)

Predisposing Factors (to Recurrent/Chronic Infections and hence Bronchiectasis)

• Endobronchial obstruction leads to local impairment of host defense mechanisms

predisposing to recurrent infections.

Slowly growing endobronchial neoplasms

Foreign-body aspiration

Bronchostenosis, from impacted secretions, or from extrinsic compression by

enlarged lymph nodes.

• Generalized impairment of pulmonary defense mechanisms occurs with

Immunoglobulin deficiency

Primary ciliary disorders

Cystic fibrosis

Non-infectious Causes

• Exposure to a toxic substance that incites a severe inflammatory response. Examples

include inhalation of a toxic gas such as ammonia or aspiration of acidic gastric contents

• An immune response in the airway may also trigger inflammation, destructive changes,

and bronchial dilatation.

Epidemiology of Bronchiectasis

• Frequency

No systematic data are available to detail the incidence or prevalence of

bronchiectasis.

Bronchiectasis remains a major cause of morbidity in less-developed countries,

especially in countries with limited access to medical care and antibiotic therapy.

• Race

No racial predilection exists other than those that may be associated with

socioeconomic status.

• Sex

Evidence suggests that non – Cystic Fibrosis-related bronchiectasis is more common

and more virulent in women, particularly slender white women older than 60 years.

In these patients, bronchiectasis is often caused by primary Mycobacterium avium

complex (MAC) infection

• Age

In the pre-antibiotic era and in In today's less-developed countries, symptoms usually

began in the first decade of life.

Today, the age of onset, except for those with Cystic Fibrosis, has moved into

adulthood.

The differences in prevalence between age groups are a direct reflection of the

differences in the prevalence of the underlying causes of bronchiectasis, lung disease,

and/or chronic infections

Clinical Manifestations of Bronchiectasis

History

• Patients typically present with persistent or recurrent cough and purulent sputum

the production which is postural related.

• Hemoptysis occurs in 50 to 70% of cases

• When a specific infectious episode initiates bronchiectasis, patients may describe a severe

pneumonia followed by chronic cough and sputum production.

• Alternatively, patients without a dramatic initiating event often describe the insidious

the onset of symptoms.

• Dyspnea or wheezing generally reflects either widespread bronchiectasis or underlying

chronic obstructive pulmonary disease.

• With exacerbations of infection, the number of sputum increases, it becomes more

purulent and often more bloody, and patients may become febrile.

Physical Examination

• Variable

• Any combination of crackles, rhonchi, and wheezes may be heard, all of which reflect the

damaged airways containing significant secretions.

• As with other types of chronic intrathoracic infection, clubbing may be present.

• Cyanosis and plethora

• Wasting and weight loss

• Patients with severe, diffuse disease, particularly those with chronic hypoxemia, may

have associated cor pulmonale and right ventricular failure.

Diagnosis and Management of Bronchiectasis

Differential Diagnosis of Bronchiectasis

• Bronchial asthma

• Chronic Bronchitis

• Acute Bronchitis

• Emphysema

• Aspiration Pneumonia/ Bacterial Pneumonia

• Pulmonary Tuberculosis

Investigations

• Refer the patient to a higher center for laboratory studies and radiographic studies.

Treatment

• Pre referral resuscitation

IV fluids

Antibiotics, and analgesics

Monitor vital signs

• Referral

A practitioner skilled in caring for patients with bronchiectasis should be consulted.

Give initial treatment and refer the patient.

Radiographic and Laboratory Findings

Chest Radiograph

• Is important but the findings are often nonspecific

• The radiograph may be normal with mild disease

Computed tomography (CT)-in advanced centers

• Provides an excellent view of dilated airways as seen in cross-sectional images

Sputum Examination

• Often reveals an abundance of neutrophils and colonization or infection with a variety of

possible organisms.

• Appropriate staining and culturing of sputum often provide a guide to antibiotic therapy.

Other investigation (to determine the cause) in advanced centers

• Fiberoptic bronchoscopy for endobronchial obstruction

• Measurement of sweat chloride levels for cystic fibrosis

• Skin testing, serology, and sputum culture for Aspergillus

• Pulmonary function tests may demonstrate airflow obstruction associated with chronic

obstructive lung disease.

Treatment

• No specific medical therapy exists for the treatment of bronchiectasis.

• Therapy is focused on the treatment of infectious exacerbations that the patient commonly

experiences, most commonly in the form of an acute bronchitis-type syndrome.

• Aggressively pursue and treat any associated or known causal condition of the

bronchiectasis.

Therapy has four major goals

• Elimination of an identifiable underlying problem

• Improved clearance of tracheobronchial secretions

• Control of infection, particularly during acute exacerbations

• Reversal of airflow obstruction

General Therapy

• Patients should stop smoking

• Patients should avoid second-hand smoke

• Patients should have adequate nutritional intake with supplementation, if necessary

• Immunizations for influenza and pneumococcal pneumonia are recommended

• Immunizations for measles, rubella, and pertussis should be confirmed

• Oxygen therapy is reserved for patients who are hypoxemic with severe disease and endstage

complications, such as cor pulmonale

Bronchial Hygiene

• With its tenacious sputum and defects in clearance of mucus, good bronchial hygiene is

paramount in the treatment of bronchiectasis.

• Postural drainage with percussion and vibration is used to loosen and mobilize secretions.

 

Antibiotics

• Antibiotics are the mainstay of treatment.

• The route of antibiotic administration varies with the overall clinical condition, with most

patients doing well on an outpatient regimens.

• Some patients benefit from a set regimen of antibiotic therapy, such as therapy for 1week

of every month.

• The choice of antibiotic is provider dependent but in general the antibiotic chosen should

have a reasonable spectrum of coverage, including the most common Gram-positive and

Gram-negative organisms.

• Treatment of the patient who is more ill or the patient with Cystic Fibrosis often requires

intravenous anti-Pseudomonas species coverage with an aminoglycoside, most often in

combination with an antipseudomonal synthetic penicillin or cephalosporin

• In acute exacerbation, broad-spectrum antibacterial agents are generally preferred.

• However, if time and the clinical situation allows, then sampling respiratory secretions

during an acute exacerbation may allow treatment with antibiotics based on specific

species identification.

Acceptable choices for the outpatient who is mild to moderately ill include

• Amoxicillin: 500 mg PO 8 hourly for 10 days

• Doxycycline: 100 mg PO every 12 hours for 10 days

• Trimethoprim-sulfamethoxazole 960mg PO 12 hourly for 10 days

• A newer macrolide

Azithromycin: Day 1: 500 mg PO; Days 2-5: 250 mg/d PO

Clarithromycin 500 mg PO bid for 7-14 days

• A second-generation cephalosporin

• One of the fluoroquinolones e.g. Levofloxacin 500 mg PO/IV once daily

• In general, the duration is 7-10 days

For patients with moderate-to-severe symptoms, parenteral antibiotics are indicated

• An aminoglycoside

Gentamicin: 3 mg/kg/d IV divided tid in normal renal function; once-a-day dosing

also effective

Amikacin: 10-15 mg/kg/d IV/IM divided bid/tid; not to exceed 1.5 g/d regardless of

higher Body Weight

• An antipseudomonal synthetic penicillin

• A third-generation cephalosporin

Ceftriaxone: IV 1-2g bid

• A fluoroquinolone

Ciprofloxacin IV 200 mg bid

 

Bronchodilators

• Bronchodilators, including beta-agonists and anticholinergics, may help some patients

with bronchiectasis, presumably reversing bronchospasm associated with airway

hyperreactivity and improving mucociliary clearance

• Salbutamol (short-acting beta 2 agonists)

Acute symptoms: 2 inhalations repeated q4-6h

• Salmeterol (Long-acting beta 2 agonists)

1 inhalation (50 mcg) bid at At least 12 h apart

Anti-inflammatory Medication

• The rationale is to modify the inflammatory response caused by the microorganisms

associated with bronchiectasis and subsequently, reduce the amount of tissue damage.

• The practical approach is to use tapering oral corticosteroids (e.g. prednisolone) and

antibiotics in the acute exacerbation and to consider inhaled corticosteroids for daily use

in patients with significant obstructive physiology on pulmonary function testing and

evidence of reversibility suggesting airway hyperreactivity.

• Beclomethasone dipropionate

200 mcg (4puffs) twice daily or 100mcg (2 puffs) 3 – 4 times daily by aerosol

inhalation

Surgical Therapy

• When bronchiectasis is localized and the morbidity is substantial despite adequate

medical therapy, surgical resection of the involved region of the lung should be considered.

Complications

• Recurrent pneumonia requiring hospitalization

• Empyema

• Lung abscess

• Hemoptysis

• Progressive respiratory failure

• Cor pulmonale

• Progressive respiratory failure and cor pulmonale are the most common causes of

pulmonary-related mortality in bronchiectasis.

Prognosis

• Overall, the prognosis is good, but it varies with the underlying or predisposing condition.

• Bronchiectasis associated with Cystic Fibrosis may carry a worsened prognosis.

• In general, patients do well if they are compliant with all treatment regimens and practice

routine preventive medicine strategies.

• Overall, the prognosis is good, but it varies with the underlying or predisposing condition.

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