Bronchiectasis

Definition

Bronchiectasis is an obstructive lung disease that results from the presence of chronic inflammatory secretions and microbes leading to the permanent dilation and distortion of airway walls, as well as recurrent infection [1]. It is associated with frequent acute exacerbations, which are an independent predictor of progressive decline in respiratory function and a poorer prognosis[2]


Bronchiectasis.png

Mechanism of Injury / Pathological Process

Bronchiectasis is chronic irreversible dilation of the bronchi on the lungs. It follows a severe lung infection or aspiration. It is more common in conditions such as Cystic Fibrosis, Rheumatoid Arthritis, Immunodeficiency, Young's syndrome and Allergic Bronchopulmonary Aspergillosis, and after childhood diseases such as whooping cough, TB and measles. Bronchiectasis that is not associated with Cystic Fibrosis is known as non-CF Brochiectasis[2]


[3]

Clinically Relevant Anatomy

Bronchiectasis involves inflammation of the airway walls, specifically the bronchial walls [4]. The airway walls are the ‘tubes’ that run from the mouth and nose and travel to the lung. The main area that is affected in bronchiectasis is the bronchi [4]. The trachea bifurcates into the right and left main bronchi, which then further divide into secondary bronchi; one for each lobe of the lung [5]. They then divide into tertiary bronchi; one for each bronchopulmonary segment [5]. For more detailed anatomy see Lung Anatomy


11287146 10152761139840952 221013016 n.jpg


The cilia are also damaged in bronchiectasis. Cilia line the airway and are attached to the epithelium. They are hair-like with tiny hooks on the tip to grab the mucous and help move the mucous up to the throat [4].

Epidemiology

It is underestimated in prevalence, incidence, and morbidity because symptoms are often ascribed to smoking. A study by Hill [6]found that one in 1000 people in the UK have bronchiectasis, with associated deaths increasing at a rate of approximately 3% per year in England and Wales [7]. Though the overall mortality rate is increasing in these countries, rates in older groups are rising whereas rates in younger groups are falling  [7]. A disproportionate amount of cases found in developing countries and in Aboriginal populations in affluent communities [8]. In some populations, an improvement in socio-economic status, housing, and education can improve overall health and reduce the incidence of respiratory infection and development of bronchiectasis [8].

Aetiology

The cause is unknown for 50% of cases, but it has been linked to inflammatory bowel disease, rheumatoid arthritis, and in 29-50% of patients, COPD [9]. There are several associated conditions with bronchiectasis including; cystic fibrosis, primary ciliary dyskinesia, lung tuberculosis, allergic bronchopulmonary aspergilosis, rheumatoid diseases, symptomatic lupus erythematosus, immune deficiency, severe childhood respiratory infection and exposure to foreign body or corrosive substance [4]. It has also been linked to an x1-antitrypsin deficiency [4]. Bronchiectasis tends to predispose patients to acquired and congenital lung infections [4].

Pathophysiology

The process begins with inflammatory damage to the bronchial walls, which then stimulates the formation of excess thick mucus [4]. The warm and moist environment of the lungs combines with the mucus to cause further inflammation and obstruction, creating an excellent environment for infection [4]. The thick mucus crushes the cilia and causes further damage. The immune response releases toxic inflammatory chemicals (i.e. neutrophils), as well as leads to fibrosis and bronchospasm if persistent[4].

Diagnostic Procedures

Currently, a high-resolution CT scan is the gold standard for diagnosis of bronchiectasis [4]. Parallel tramlines and ring shadows may be present on the scan, indicating thickened airway walls and dilated airways, respectively[4]. There may also be ‘glove finger shadows’, which are finger –like projections that represent the dilated bronchi filled with solidified secretions[4].
Spirometry will simply identify if there is an airway obstruction, but this can be indicative of many other diseases[4].
Microbiology can also be used to identify the bacteria present during an exacerbation [4]. A sputum sample is sent off and the results are returned with the incidence of bacterial colonization measured [4].

Clinical Manifestations

As delicate cilia are often damaged due to the presence of thick mucus, the voluminous quantities of sputum formed cannot be efficiently cleared[4]. These secretions will lead to the production of wheezes, coarse crackles and squeaks on auscultation. Often times, patients will also present with muscular dysfunction due to inflammation, gas exchange abnormalities, inactivity, malnutrition, hypoxia and medications [10]. Dyspnoea on exertion seems to be a major clinical manifestation as it is experienced by three out of four patients. Other physical manifestations include chest pain, snoring, finger clubbing, fatigue, persistent cough, recurrent infection, and loss of appetite[4]. Stress incontinence can also be a result of excess coughing. Bronchiectasis tends to also have psychological manifestations, such as anxiety, depression, reduced confidence, altered relationships and time off work[4].
Exacerbations can occur several times a year and are identified by four or more of the following signs and/or symptoms: change in sputum, increased dyspnoea, increased cough, fever of greater than 38°, increased wheeze, decreased exercise tolerance, fatigue, lethargy, and radiographic signs of a new infection[4].

Physiotherapy and Other Management

The key to management of bronchiectasis is through education and systemic management. Currently, antibiotics are used at the first sign of change in sputum colour[4] and longterm use of antibiotics is recommended for people who experience 3 or more exacerbations a year[11]. Since antibiotics do not help with the persistent inflammation in the airways, inhaled steroids are taken as an anti-inflammatory and to decrease sputum production[4]. Brochodilators tend to help patients who also have co-existing COPD and asthma[11]. A review and a controlled study found that many people with bronchiectasis also have a Vitamin D deficiency and prescribing Vitamin D may have an anti-inflammatory and anti-infective role[12][13].


Physiotherapy has a very valuable role in aiding with symptoms of bronchiectasis. Since mucociliary clearance is reduced to about 15% of normal, patients tend to cough more[4]. Physiotherapy treatments are aimed at aiding secretion clearance, managing fatigue induced by the effort of ineffective clearance and increased coughing. The most common and effective treatments are:

  • Active Cycle of Breathing Technique (ACBT) is a commonly taught technique and is often used with Postural drainage and manual drainage[14]. Its purpose is to loosen and clear excess pulmonary secretions, improve the effectiveness of a cough and to improve lung ventilation and function. It consists of 3 main stages:
    • Breathing Control
    • Deep Breathing Exercises or Thoracic Expansion Exercises
    • Huffing or Forced Expiratory Technique (FET)[15]
  • Forced expiration technique, sometimes referred to as a huff. It is part of the ACBT but can be used alone. A huff is very effective at clearing secretions especially when combined with other airway clearance techniques.[16]
  • Manual Therapy is a popular treatment technique and is often used when the patient is fatigue or experiencing an exacerbation of symptoms. It describes techniques that involve external forces to the chest wall to loosen mucus and includes any combination of percussion, shaking, rib springing, vibrations and over pressure[17]. Because of the nature of the technique it is contraindicated in patients that are taking anticoagulants or that have osteoporosis[18]. The aim of treatment is to:
    • Loosen secretions
    • Reduce fatigue
    • Increase the effectiveness of other treatment techniques
  • Postural Drainage (or modified postural drainage) is an effective treatment that incorporates gravity-assisted techniques to help clear secretions from specific segments of the lungs, and often requires tilting the head down to clear secretions from the middle and lower lobes. PD is commonly used in conjunction with other techniques like ACBT, percussion, coughing or huffing and studies have found using PD with these techniques produced a greater amount of sputum[19][20]. Although PD is effective in secretion clearance it is time consuming and often found to be less tolerated than techniques that are performed in sitting[20]. Where tilting the head down is contraindicated or not tolerated then modified postural drainage (mPD) positions can be used instead and in cases where gastroesophageal reflux disease GORD) is present and exacerbated even when using modified PD then it is suggested to use a technique that can be performed in sitting.
  • Autogenic Drainage is a technique that utilises breathing control to clear secretions from the airways. The aim is to vary the depth, rate and location of lung volumes during respiration to move secretions from the smaller airways to the larger airways for easier expectoration. It consists of three phases:
    1. Mobilising (unstick) phase - involves breathing as much air out of the lungs as possible and resisting the urge to cough. During this phase crackles may be heard.
    2. Collecting phase - as the secretions get louder the rate and depth of the breaths change, the speed of breathing out is faster (but not too fast to stimulate a cough) and are felt more in the middle of the chest. This assists the movement of secretions from the smaller airways to the larger airways.
    3. Clearing phase - as the secretions get louder the aim is now to take full, slow deep breaths in, followed by a fast breath out. Suppress the urge to cough and after three deep breaths huff to expel the secretions. Often the huff is enough to clear secretions but if they are ineffective this is the stage where a cough may be effective in clearing secretions.
  • Positive Expiratory Pressure (PEP) is a technique that describes breathing against resistance, and can be performed either through a device or against pursed lips. It is a technique which is recommended when other techniques have not been effective or are contraindicated; it has been found to have no adverse effect of GORD.[21] The increase in pressure creates back pressure in the airways during expiration. This may cause a build up of gas behind the mucus, temporarily increasing functional capacity, and improving mucus clearance.[22]

High Frequency Chest Wall Oscillation is achieved by wearing a vest that emulates chest physiotherapy. The vest applies positive pressure air pulses to the chest which causes vibrations that loosen and thin mucus, This along with an intermittent cough or huff assists with the clearance of secretions. This device allows people to perform therapy in their own time, allowing them some control and less dependence on other people.

Intrapulmonary Percussive Ventilation is another technique that relies on a device to assist with the clearance of secretions. An intrapulmonary percussive ventilator (IPV) is a machine that delivers short bursts of air through a mouthpiece that vibrates the airway walls[23]. It is indicated for short-term use when other techniques are contraindicated or have proved ineffective.

Intermittent Positive Pressure Breathingi(IPPB), it is an expensive piece of equipment[24] ands usesually only ud when all other clearance techniques have proved to be ineffective[11]. It is commonly seen in Intensive Care and gives positive pressure as the patient breathes in, and during expiration it creates negative pressure making the cough stronger and more effective

Physical Exercise is recommended for respiratory conditions, including bronchiectasis with the aim of improving aerobic capacity and, fitness and endurance. A study by Lee et al concluded that exercise resulted in short term improvements and had an impact on dyspnoea and fatigue, and resulted in less exacerbations over a 12 month period[25].

Outcome Measures

In order to assess the effectiveness of treatment and changes in quality of life, patients can complete a St. George’s Respiratory Questionnaire (SGRQ) [4]. The SGRQ is a commonly used questionnaire to measures health related quality of life in patients with respiratory conditions [26].

References

  1. Barker AF. Bronchiectasis. New England Journal of Medicine 2002; 346: 1383-93.
  2. 2.0 2.1 Martinez-Garcia M, Soler-Cataluna J, Perpina-Tordera M, Roman-Sanchez P, Soriano J: Factors associated with lung function decline in adult patients with stable non-cystic fibrosis bronchiectasis. Chest 2007, 132:1565–1572
  3. salamhossein. Bronchiectasis Animation - What is Bronchiectasis? Video.mp4. Available from: https://www.youtube.com/watch?v=uNeprw1rsgE [last accessed 18/5/15]
  4. 4.00 4.01 4.02 4.03 4.04 4.05 4.06 4.07 4.08 4.09 4.10 4.11 4.12 4.13 4.14 4.15 4.16 4.17 4.18 4.19 4.20 4.21 4.22 Hough A. Physiotherapy in Respiratory and Cardiac Care: an evidence-based approach. 4th ed. Hampshire: Cengage Learning EMEA, 2014.
  5. 5.0 5.1 Palastanga N, Soames R. Anatomy and human movement: structure and function. 6th ed. New York: Churchill Livingstone; 2012.
  6. Hill AT, Welham S, Reid K, Bucknall CE. British Thoracic Society national bronchiectasis audit 2010 and 2011. Thorax 2012; 1:1-3.
  7. 7.0 7.1 Roberts HJ, Hubbard R. Trends in bronchiectasis mortality in England and Wales. Respiratory Medicine 2010; 104: 981-5.
  8. 8.0 8.1 Chang AB, Marsh RL, Vaughan-Smith HC, Hoffman LR. Emerging drugs for bronchiectasis. Informa healthcare 2012; 17: 361-378.
  9. Goeminne P, Dupont L. Non-cystic fibrosis bronchiectasis: Diagnosis and management in the 21st century. Postgrad Med J 2010; 86: 493-501.
  10. Ozalp O, Inal-Ince D, Calik E, Vardar-Yagli N, Saglam M, Savci S, et al. Extrapulmonary features of bronchiectasis: muscle function, exercise capacity, fatigue, and health status. Multidisciplinary Respiratory Medicine 2012; 7: 1-6.
  11. 11.0 11.1 11.2 Hill AT, Sullivan AL, Chalmers JD, De Soyza A, Elborn JS, Floto RA, Grillo L, Gruffydd-Jones K, Harvey A, Haworth CS, Hiscocks E. British Thoracic Society Guideline for bronchiectasis in adults. Thorax. 2019 Jan 1;74(Suppl 1):1-69.
  12. Bartley J, Garrett J, Grant CC, Camargo CA. Could vitamin D have a potential anti-inflammatory and anti-infective role in bronchiectasis?. Current infectious disease reports. 2013 Apr 1;15(2):148-57.
  13. Chalmers JD, McHugh BJ, Docherty C, Govan JR, Hill AT. Vitamin-D deficiency is associated with chronic bacterial colonisation and disease severity in bronchiectasis. Thorax. 2013 Jan 1;68(1):39-47.
  14. O’Neill B, Bradley JM, McArdle N, et al. The current physiotherapy management of patients with bronchiectasis: a UK survey. Int J Clin Pract 2002;56:34–5.
  15. Larner E, Galey P. Active cycle of breathing technique. Available from: http://www.nnuh.nhs.uk/publication/download/active-cycle-of-breathing-technique-v3 (accessed 24 March 2019)
  16. Van der Schans CP. Forced expiratory manoeuvres to increase transport of bronchial mucus: a mechanistic approach. Monaldi archives for chest disease= Archivio Monaldi per le malattie del torace. 1997 Aug;52(4):367.
  17. Syed N, Maiya AG, Siva Kumar T. Active Cycles of Breathing Technique (ACBT) versus conventional chest physical therapy on airway clearance in bronchiectasis–a crossover trial. Advances in Physiotherapy. 2009 Jan 1;11(4):193-8.
  18. Diehl N, Johnson MM. Prevalence of Osteopenia and Osteoporosis in Patients with Noncystic Fibrosis Bronchiectasis. South Med J. 2016;109(12):779-83
  19. Ramos EM, Ramos D, Moreira GL, Macchione M, Guimarães ET, Rodrigues FM, de Souza AA, Saldiva PH, Jardim JR. Viscoelastic properties of bronchial mucus after respiratory physiotherapy in subjects with bronchiectasis. Respiratory care. 2015 May 1;60(5):724-30.
  20. 20.0 20.1 Flude LJ, Agent P, Bilton D. Chest physiotherapy techniques in bronchiectasis. Clinics in chest medicine. 2012 Jun 1;33(2):351-61.
  21. Lee AL, Denehy L, Wilson JW, et al. Upright positive expiratory pressure therapy and exercise: effects on gastroesophageal reflux in COPD and bronchiectasis. Respir Care 2012;57:1460–7.
  22. McIlwaine M, Button B, Dwan K. Positive expiratory pressure physiotherapy for airway clearance in people with cystic fibrosis. Cochrane Database of Systematic Reviews. 2015(6).
  23. Paneroni M, Clini E, Simonelli C, et al. Safety and efficacy of short-term intrapulmonary percussive ventilation in patients with bronchiectasis. Respir Care 2011;56:984–8.
  24. Eggertsen SC. Intermittent positive pressure breathing and the treatment of acute asthma. The Journal of family practice. 1983 May;16(5):909-13.
  25. Lee AL, Hill CJ, Cecins N, et al. The short and long term effects of exercise training in non-cystic fibrosis bronchiectasis--a randomised controlled trial. Respir Res 2014;15:44.
  26. Ferrer M, Miravitlles M, Villasante C, Alonso J, Sobradillo V, Gabriel R, et al. Interpretation of quality of life scores from the St George's Respiratory Questionnaire. Eur Respir J 2002;19(3):405-13.