Bronchiectasis PDF

Bronchiectasis DR MARWAN MAJEED IBRAHIM MRCP RESPIRATORY MEDICINE Bronchiectasis means abnormal dilatation of the bronchi. Chronic suppurative airway infection with sputum production, progressive scarring and lung damage occur, whatever the cause. There are several causes of bronchiectasis and tub...

Bronchiectasis DR MARWAN MAJEED IBRAHIM MRCP RESPIRATORY MEDICINE Bronchiectasis means abnormal dilatation of the bronchi. Chronic suppurative airway infection with sputum production, progressive scarring and lung damage occur, whatever the cause. There are several causes of bronchiectasis and tuberculosis is the most common worldwide. Etiology and pathology Localized bronchiectasis may occur due to the accumulation of pus beyond an obstructing bronchial lesion, such as enlarged tuberculous hilar lymph nodes, a bronchial tumor or an inhaled foreign body. The bronchiectatic cavities may be lined by granulation tissue, squamous epithelium or normal ciliated epithelium. There may also be inflammatory changes in the deeper layers of the bronchial wall and hypertrophy of the bronchial arteries. Chronic inflammatory and fibrotic changes are usually found in the surrounding lung tissue, resulting in progressive destruction of the normal lung architecture in advanced cases. Clinical features Physical signs in the chest may be unilateral or bilateral. If the bronchiectatic airways do not contain secretions and there is no associated lobar collapse, there are no abnormal physical signs. When there are large amounts of sputum in the bronchiectatic spaces, numerous coarse crackles may be heard over the affected areas. Collapse with retained secretions blocking a proximal bronchus may lead to locally diminished breath sounds, while advanced disease may cause scarring and overlying bronchial breathing. Scattered rhonchi can be heard. Investigations Chest radiograph (CXR) sensitivity is only 50%, classically shows ‘ring shadows’ and ‘tramlines’— indicating thickened airways, and the ‘gloved finger’ appearance. Consolidation around thickened and dilated airways HRCT chest is the investigation of choice and is 97% sensitive in detecting disease. typically shows airway dilatation to within 1cm of the lung periphery, bronchial wall thickening, and the airway appearing larger than its accompanying vessel (signet ring sign). If the bronchiectasis is localized to a single lobe, CT is useful to determine whether a central obstructing lesion is present.  Sputum microbiology : Standard microscopy, culture, and sensitivity (MC&S), acid- fast bacillus (AFB) and atypical mycobacteria, and fungal cultures Immunoglobulins A, M, G Aspergillus precipitins, Aspergillus- specific radioallergosorbent test (RAST), total IgE Lung function FEV1/ FVC and flow- volume loop with reversibility testing In certain cituation we have to investigate for: CFTR mutation screen and sweat test Vaccination response to tetanus, H. influenza B, and pneumococcal antibodies. If pneumococcal antibodies are low, arrange vaccination with 23 valent polysaccharide pneumococcal vaccine and repeat antibody testing 6 weeks later; failure to generate adequate pneumococcal antibody levels is suggestive of an immunodeficiency Detailed immunological investigation (including neutrophil and lymphocyte function studies, genetic analysis) Skin tests/RAST to identify specific sensitizers (usually Aspergillus)  Bronchoscopy to exclude a foreign body if suggested by CT; obtain microbiological samples if unusual clinical presentation or failure to respond to standard antibiotics Nasal nitric oxide +/ - brushings/ biopsy (in tertiary centre) to assess ciliary beat frequency with video microscopy to exclude primary ciliary dyskinesia Saccharin test This time should not exceed 20 minutes but is greatly prolonged in patients with ciliary dysfunction. Ciliary beat frequency may also be assessed from biopsies taken from the nose. Structural abnormalities of cilia can be detected by electron microscopy. A1AT levels if deficiency suspected Vasculitis screen (RF, ANCA, ANA, ENA, and anti- CCP antibodies) if connective disease/ arthritis/ vasculitis associated bronchiectasis suspected HIV serology. Management Physiotherapy :Patients should be shown how to perform regular daily physiotherapy to assist the drainage of excess bronchial secretions. Antibiotic therapy For most patients with bronchiectasis, the appropriate antibiotics are: Co amoxiclav, macrolides and tetracyclines  When secondary infection occurs with staphylococci and Gram- negative bacilli, in particular Pseudomonas species, antibiotic therapy becomes more challenging and should be guided by the microbiological sensitivities. For Pseudomonas, oral ciprofloxacin (500–750 mg twice daily) or an intravenous anti-pseudomonal β-lactam (e.g. piperacillin– tazobactam or ceftazidime) will be required for 14 days. Hemoptysis in bronchiectasis often responds to treatment of the underlying infection, although percutaneous embolization of the bronchial circulation by an interventional radiologist may be necessary in severe cases  Surgical treatment Excision of bronchiectatic areas is indicated in only a small proportion of cases. In progressive forms of bronchiectasis, resection of destroyed areas of lung that are acting as a reservoir of infection should be considered only as a last resort. Cystic Fibrosis (CF) is the most common fatal genetic disease in Caucasians, with autosomal recessive inheritance, a carrier rate of 1 in 25, and an incidence of about 1 in 2500 live births. CF is the result of mutations affecting a gene on the long arm of chromosome 7, which codes for a chloride channel known as cystic fibrosis transmembrane conductance regulator (CFTR); this influences salt and water movement across epithelial cell membranes. The most common CFTR mutation in northern European and American populations is ΔF508. Defect causes increased sodium and chloride content in sweat and increased resorption of sodium and water from respiratory epithelium. Relative dehydration of the airway epithelium is thought to predispose to chronic bacterial infection and ciliary dysfunction, leading to bronchiectasis. The gene defect also causes disorders in the gut epithelium, pancreas, liver and reproductive system. Clinical features The lungs are macroscopically normal at birth, but bronchiolar inflammation and infections usually lead to bronchiectasis in childhood. At this stage, the lungs are most commonly infected with Staph. aureus; however, in adulthood, many patients become colonised with P. aeruginosa, Stenotrophomonas maltophilia or other Gram-negative bacilli. Recurrent exacerbations of bronchiectasis, initially in the upper lobes but subsequently throughout both lungs, cause progressive lung damage, resulting ultimately in death from respiratory failure. Most men with CF are infertile due to failure of development of the vas deferens, but microsurgical sperm aspiration and in vitro fertilization are possible. Management Treatment of CF lung disease: The management of CF lung disease is that of severe bronchiectasis. All patients with CF who produce sputum should perform chest physiotherapy daily, and more frequently during exacerbations. While infections with Staph. aureus can often be managed with oral antibiotics, intravenous treatment (frequently self- administered at home through an implanted subcutaneous vascular access device) is usually needed for Pseudomonas infection.  Resistant strains of P. aeruginosa, Stenotrophomonas maltophilia and Burkholderia cepacia are the main culprits and may require prolonged treatment with unusual combinations of antibiotics. Aspergillus and non-tuberculous mycobacteria are also frequently found in the sputum of patients with CF but in most cases these behave as benign ‘colonizers’ of the bronchiectatic airways and do not require specific therapy. Mycobacterium abscessus, which is multi-resistant, may be transmissible between patients with CF and can cause progressive lung destruction that is hard to treat. Some patients have coexistent asthma, which is treated with inhaled bronchodilators and inhaled glucocorticoids. Treatment of non-respiratory manifestations of CF There is a clear link between good nutrition and prognosis in CF. Malabsorption occurs in 85% of patients due to exocrine pancreatic failure and is treated with oral pancreatic enzymes and vitamin supplements. Diabetes eventually develops in over 25% of patients and often requires insulin therapy. Osteoporosis secondary to malabsorption and chronic ill health should be sought and treated with vit D, Ca and bisphosphonates. Noval therapies for cystic fibrosis Small molecules designed to correct the function of particular CFTR defects are being developed. Ivacaftor (a CFTR ‘potentiator’), is now an established oral treatment for the 5% of patients with the G551D mutation, causing sustained improvements in FEV1 and weight, and normalizing the sweat test. The combination of ivacaftor and lumacaftor (a CFTR ‘corrector’) has been found to have modest short-term benefit in patients with DF508 mutations. Improved versions of these treatments may soon offer similar benefits for these patients