Respiratory conditions Flashcards
What are examples of obstructive airway disease?
Asthma, chronic bronchitis and emphysema, (COPD).
What is ACOS?
ACOS is asthma/COPD overlap syndrome, patients with features of both COPD and asthma, e.g. COPD with reversibility and eosinophilia who are steroid responsive.
What is asthma?
Asthma is a chronic inflammatory disease of the airways.
What is the asthma triad?
The asthma triad is reversible airflow obstruction, airway hyper-responsiveness and airway inflammation.
What are the hallmarks of remodeling in asthma?
Thickening of the basement membrane, collagen deposition in the submucosa, and hypertrophy of smooth muscle.
Describe the inflammatory cascade in asthma.
A genetic predisposition to asthma and the presence of triggers causes eosinophilic inflammation. Eosinophils release inflammatory mediators in the form of TH2 cytokines. TH2 cytokines cause hyper-reactivity of airway smooth muscle.
How can a genetic predisposition to triggers of asthma be treated?
Avoidance of those triggers, e.g. allergens.
How can eosinophilic inflammation of asthma be treated?
Anti-inflammatory drugs, e.g. corticosteroids or cromones.
How can inflammatory mediators and TH2 cytokines in asthma be treated?
Anti-leukotrienes/histamine, anti-IgE and anti-IL5.
How can hyper-reactivity of asthma be treated?
By bronchodilators, e.g. beta-2-agonists or muscarinic antagonists.
What may inflammation in asthma show on photomicrographs?
Desquamation of airway epithelium, numerous eosinophils, thickening of basement membrane.
What signs and symptoms may point to a diagnosis of asthma?
Episodic symptoms, diurnal variability (worse at night and early morning), non-productive cough, or wheeze due to turbulent airflow. Patient may also experience symptoms in response to triggers, have associated atopy or a FHx of asthma.
What is the forced expiratory ratio in asthma?
Asthmatics have a reduced forced expiratory ratio of <75%, but experience >15% reversibility in response to salbutamol.
How may a diagnosis of asthma be made?
Provocation testing leading to bronchospasm, by exercise or exposure to histamine/methacholine/mannitol.
What are the main components of COPD?
COPD is a multicomponent disease process consisting of: mucociliary dysfunction, inflammation and tissue damage/
What are the characteristics and symptoms of COPD?
A patient experiences frequent exacerbations, reduced lung function. They become increasingly breathless and have a worsening quality of life due to obstruction and disease progression.
What are the triggers and pathophysiology of COPD?
Exposure to inhaled noxious particles or gases causes lung inflammation which may lead to COPD if normal protective/repair mechanisms are defective.
Irritants activate macrophages and airway epithelial cells to release neutrophil cytokines, IL-8 and LTB4. Neutrophils and macrophages release proteases to break down connective tissues in lung parenchyma (alveolar wall destruction–> emphysema) and stimulate mucus hypersecretion (chronic bronchitis).
How may mucociliary function be compromised?
Mucociliary function may be compromised by damage to the cilia due to enzymes, e.g. neutrophil elastase, attracted to airways by toxins.
COPD patients have recurrent resp. tract infection, how may this damage the respiratory mucosa?
Commonly H. influenza, which may break down epithelial cell walls, leading to loss of ciliated cells and damaging airway tissue.
Why does emphysema occur?
Alveolar destruction, causes increased air spaces. Due to proteases, e.g. neutrophil elastase, and may relate to an imbalance of proteases and anti-proteases.
Give 4 features of chronic bronchitis.
- Chronic neutrophilic inflammation.
- Mucus hypersecretion.
- Mucociliary dysfunction.
- Altered lung microbiome.
- Smooth muscle spasm and hypertrophy.
- Partially reversible.
Give the features of emphysema.
- Alveolar destruction.
- Impaired gas exchange.
- Loss of bronchial support.
- Irreversible.
What are indicators of high risk COPD?
2 or more exacerbations within the past year, or an FEV1 <50% of predicted.
What are the signs and symptoms of COPD?
Chronic symptoms, smoker, non-atopic, a daily productive cough, progressive breathlessness, frequent infective exacerbations.
Chronic bronchitis: wheezing.
Emphysema: reduced breath sounds.
Describe the chronic cascade of COPD.
Progressive fixed airflow obstruction leads to impaired alveolar gas exchange, leading to resp. failure (decreased PaO2 and increased PaCO2). This leads to pulmonary hypertension, RV hypertrophy/failure and eventually death.
Non-pharmacological treatment methods of COPD?
smoking cessation, immunization, physical activity, domiciliary oxygen and venesection.
Pharmacological treatment methods of COPD?
LAMA (tiotropium).
LABA (salmeterol or formeterol).
LAMA-LABA combo
LABA-ICS combo: beclometasone+formeterol.
LAMA-LABA/ICS combo: glycopyronnium-formeterol-beclometasone.
What is the FVC and TLCO of asthmatics?
Normal.
What is the FVC and TLCO of COPD?
Reduced.
What is DPLD?
Diffuse parenchymal lung disease. It is an interstitial lung disease caused by disease of alveolar structures. This results in impaired alveolar gas exchange, decreased PaO2 and decreased SaO2. However, CO2 exchange is unimpaired.
Give causes of consolidation of alveolar air spaces.
Infective pneumonia, infarction, rheumatoid disease, drugs.
What is extrinsic allergic alveolitis?
Aka hypersensitivity pneumonitis type 3. It is called farmers lung as it is related to avian keeping, e.g. pigeons, budgies.
What is sarcoidosis?
Sarcoidosis is a multi-system disease, involving lymphadenopathy, erythema nodosum, uveitis, myocarditis and neuropathy,
CXR may show bilateral hilar lymphadenopathy and lung infiltrates.
Non-caseating granuloma may also be found within the lung.
Give examples of drugs which may cause drug-induced alveolitis.
Amiodarone, methotrexate, Gold, bleomycin.
Which gas may cause alveolitis?
Chlorine.
What autoimmune conditions may cause alveolitis?
systemic lupus erythematosus, polyarteritis, Wegeners, Chrug-Strauss, Bechet’s.
What is pneumoconiosis and what are its fibrogenic causes?
Pneumoconiosis is an occupational, restrictive lung disease caused by the inhalation of dust. Fibrogenic causes include asbestosis and silicosis.
What are non-fibrogenic causes of pneumoconiosis?
Iron (siderosis), tin (stenosis), barium (baritosis).
What are the clinical signs and symptoms of DPLD?
Breathless on exertion, cough without wheeze, finger clubbing, inspiratory lung crackles, central cyanosis and pulmonary fibrosis (end-stage due to chronic inflammation).
How may DPLD be diagnosed?
- History: occupation, drugs, pets, arthritis.
- FEV1/FVC ratio <75%. Normal peak flow.
- Reduced gas diffusion, reduced PaO2 and reduced SaO2.
- antibodies.
- Bilateral diffuse alveolar infiltrates on CXR.
- ground glass on high res. CT
Treatment of DPLD.
Remove triggers, treat inflammation with immunosuppressors.
1st line: corticosteroids e.g. oral prednisolone.
2nd line: oral azathioprine.
Anti-fibrotic agents.
Anti-oxidant agents.
Oxygen, if hypoxic.
Lung transplant.
Give an example of effort dependent pulmonary function tests.
Spirometry: forced expiratory flow rate.
Give examples of effort independent pulmonary function tests.
Spirometry: relaxed vital capacity. Helium/N2 washout static lung volumes. Whole body plethysmography. Impulse oscillometry. Exhaled breath nitric oxide.
Give examples of pulmonary function gas diffusion tests.
CO transfer factor.
Arterial blood gases at rest.
SaO2 during exercise.
Describe the spirometry of Asthma.
Asthma has normal FVC and reduced FEV1.
Describe the spirometry of COPD.
COPD has both reduced FVC and FEV1.
Describe the shape of an expiratory flow-volume curve of volume dependent expiratory airway closure diseases, and the diseases that produce this curve.
Asthma and chronic bronchitis. Curve follows shape of normal, but is reduced.
Describe the shape of an expiratory flow-volume curve of pressure dependent expiratory airway closure diseases, and the diseases that produce this curve.
Emphysema. Curve is more rounded, and significantly reduced in comparison to normal curve.
Describe the PEFR, FEV1, FVC, FEV1/FVC ratio and FEV1 response to beta-2-agonist of asthma.
In asthma, PEFR is reduced, FEV1 is reduced, FVC is normal. The FEV1/FVC ratio is <75%, but shows >15% improvement in response to beta-2-agonist.
Describe the PEFR, FEV1, FVC, FEV1/FVC ratio and FEV1 response to beta-2-agonist of COPD.
PEFR is reduced, FEV1 is reduced, FVC is reduced. FEV1/FVC ratio is <75% and shows <15% improvement in response to beta-2-agonist.
Describe the PEFR, FEV1, FVC, FEV1/FVC ratio and FEV1 response to beta-2-agonist of restrictive lung disease.
PEFR is normal, FEV1 is reduced, FVC is reduced. FEV1/FVC ratio is normal and shows no improvement in response to beta-2-agonists.
Describe the static lung volume of COPD.
In COPD there is hyper-inflation of static lung volume.
Describe the static lung volume of restrictive lung disease.
In restrictive lung disease, TLC is reduced.
In which conditions might TLCO be reduced?
TLCO is reduced in anaemia, emphysema, interstitial lung disease, pulmonary oedema, bronchiectasis, pulmonary emboli.
Two methods of measuring airway resistance?
Whole body plethysmography or more commonly - impulse oscillometry.
High levels of exhaled NO reflect what?
Uncontrolled asthmatic inflammation.
Outline the pathology of COPD.
smoking or air pollution causes stimulation of alveolar macrophages, which produce cytokines. Cytokines activate neutrophils, CD8-T-cells. These cause release of matrix metalloproteinases and free radicals.
Describe chronic bronchitis.
Chronic bronchitis is the inflammation of bronchi and bronchioles. Chronic cough productive of sputum. Infective exacerbations produce purulent sputum. Patients present with increasing breathlessness.
Describe emphysema.
Distension and damage to alveoli results in destruction of acinial pouching in alveolal sacs.
When should you image to detect a pulmonary thromboembolism?
If a CXR is normal, perform a V/Q scan.
If radiation is to be avoided/leg is swollen, consider ultrasound (of leg for DVT).
If CXR is abnormal/massive PE is suspected, do a CT pulmonary angiogram.
Symptoms of lung cancer?
25% may be asymptomatic. Symptoms include cough, wheeze, haemoptysis, breathlessness, recurrent pneumonia, hypercalcaemia, weight loss, hoarseness, finger clubbing, persistent enlarged supra-clavicular nodes.
Describe peripheral lung tumours.
Tumours arising beyond the hilum.
Describe central tumours.
Tumours arising at, or close to the hilum.
What are the “cardinal signs” of central lung tumours?
hilar enlargement and distal collapse/consolidation.
What do T, N and M stand for in the international staging system?
T = tumour size. N = lymph node staging. M = metastases.
What is a CT good for with regards to tumours?
Diagnosis. It enables assessment of tumour size, and shows intracranial metastases. It also guides biopsy of peripheral lesions. Can be useful for staging, but a PET scan is better.
What is a PET CT good for with regards to tumours?
Staging. It enables the detection of nodal and distant metastases. It’s also good at outlining tumours within areas of collapse. Often upstages people.
What is an MR good for with regards to lung tumours?
It doesn’t require IV contract, views in 3 planes and good soft tissue differentiation. However its costly and time consuming, and better spatial resolution is achieved with CT.
What is the main treatment method of small cell lung cancer?
Chemotherapy.
What is ultrasound useful for, with regards to the respiratory system?
Pleural effusion, subphrenic collection, seeing diaphragm movement and guiding drainage.
What is stridor?
Worrying. Difficulty breathing in, causing coarse audible wheeze. May be symptom of cancer.
Why might a lung tumour cause a hoarse voice?
It may invade the recurrent laryngeal nerve, causing palsy.
What might invasion of the pericardium by a lung tumour cause?
Breathlessness, atrial fibrillation, pericardial effusion.
What might invasion of the oesophagus by a lung tumour cause?
Dysphagia for solids.
Where are pancoast tumours found?
In the apex of the lung, they may invade the brachial plexus and cause weakness of hands/arms.
what can often happen when a primary lung tumour invades the pleural space?
It may cause large volumes of pleural fluid to accumulate, causing breathlessness.
What may happen when a primary lung tumour invades the SVC?
It obstructs blood drainage from the arms and head. A patient may complain of puffy eyelids and a headache. Distension of veins may also be seen.
What might chest wall invasion by lung cancer cause?
Destruction of ribs, causing localized chest pain made worse by movement. If bone is eroded, patients often have worse pain at night.
What may happen if a tumour encases and erodes into an artery?
It may cause sudden death due to massive haemoptysis.
Where are common sites of metastases for lung cancer?
Liver, brain, bone, adrenal glands, skin, lung.
What symptoms might a patient with cerebral metastases experience?
Slow onset of weakness, visual disturbance, headaches (worse in morning with no photophobia), fits.
What symptoms might a patient with bone metastases experience?
Localised pain which is worse at night, or fractures due to trivial mechanical stress. May be detected by isotope bone scans.
Symptoms of hypercalcaemia?
Headaches, confusion, thirst and constipation.
Why is thrombophlebitis a common manifestation of cancer?
Cancer patients have increased coagulability of the blood.
What are red flag symptoms you must ask about when concerned about lung cancer?
Cough (sputum or not?), haemoptysis, smoker, breathless, weight loss, fatigue, recurrent infection, chest pain.
What should you look for when examining a patient and concerned about lung cancer?
Finger clubbing, breathless, cough, weight loss, bloated face, hoarse voice, lymphadenopathy, dull percussion, tracheal deviation, stridor, enlarged liver.
What is the function of a PET scan?
Analyses tissue uptake of radiolabelled glucose causing tissues with high metabolic activity “light up”. It assessed function, rather than structure.
When might bronchoscopy be used in investigation of lung cancer?
If suspected tumour in central area of bronchial tree.
When might CT guided biopsy be used in investigation of lung cancer?
If there is a suspected peripheral tumour.
When might an endobrachial ultrasound be used in investigation of lung cancer?
To enable visuation of hilar and mediastinal structures, and to target and sample lymph nodes.
When might a thoracoscopy be used in investigation of lung cancer?
Deflation of lungs to visualize and biopsy pleural surfaces.
What are the treatment options for non-small cell lung cancer?
Surgery or radical radiotherapy. Tend to be less responsive to chemotherapy.
Side effects of chemotherapy?
Nausea, vomiting, tiredness, bone marrow suppression (opportunistic infection, anaemia), hair loss and pulmonary fibrosis.
How do radical and palliative radiotherapy differ?
Radical has the intent to cure, and palliative is a delaying tactic useful for metastases.
Radiotherapy disadvantages?
Damage to spinal cord, oesophagus, adjacent lung tissue. Limited to area of beam
Define pleural effusion.
The abnormal collection of fluid in the pleural space. Large unilateral effusions should raise concern. They may be aspirated, to determine if transudate or exudate.
What investigations might you undertake with regards to pleural effusion?
PA CXR. Pleural aspirate. Biochemistry - transudate or exudate? Cytology. Culture. Contrast enhanced CT Pleural tap Bleural biopsy.
what might straw-coloured pleural fluid suggest?
Cardiac failure, hypoalbuminaemia.
What might bloody pleural fluid suggest?
Trauma, malignancy, infection, infarction.
what might milky/turbid pleural fluid suggest?
Empyema, chylothorax
What might foul smelling pleural fluid suggest?
Anaerobic empyema.
What might food particles in the pleural fluid suggest>
Oesophageal rupture.
What might cause bilateral pleural effusions.
LVF, PTE, drugs, systemic pathology.
What is transudative pleural fluid? What are its causes?
Protein <30g/l. It may be caused by heart failure, liver cirrhosis, hypoalbuminaemia, atelectasis, peritoneal dialysis.
What is exudative pleural fluid? What are its causes?
Protein>30g/l. Caused by malignancy, infection inc. TB, pulmonary infarct, asbestos.
What does lymphocytes in pleural fluid cytology suggest?
TB, malignancy. Though, any long standing effusion will eventually become lymphocytic.
What do neutrophils in pleural fluid suggest?
An acute process.
Define mesothelioma,
Mesothelioma is an uncommon, malignant tumour of the lung lining, or rarely of the lining of the abd. cavity. Usually due to asbestos exposure.
What are contributory causes and symptoms of mesothelioma.
Asbestos exposure. Often takes 30-40 years to develop. Symptoms include: breathlessness, chest pain, weight loss, fever, sweating and cough.
What investigations should be carried out when mesothelioma is suspected?
Imaging, pleural fluid aspirate and biopsy (thoracoscopy or CT/US guided).
How is mesothelioma treated?
Pleurodese effusions, radiotherapy, surgery, chemotherapy, palliative care.
How to treat pleural effusion due to LVF?
Diuretics.
How to treat pleural effusion due to infection?
Drain, antibiotics and may require surgery.
How to treat pleural effusion due to malignancy>
Drain, pleurodesis and long term pleural catheter.
What factors make pneumothorax more likely?
Tall thin males, smokers, cannabis use, underlying lung disease.
How do pneumothorax present?
SOB, hypoxia, acute onset pleuritic chest pain. Tachycardia, hyper-resonant, reduced chest expansion, quiet breath sounds on auscultation and a click on auscultation (Hamman’s sign).
