Respiratory Flashcards
What is Chronic obstructive pulmonary disease?
A chronic lung condition characterised by breathlessness due to poorly reversible and progressive airflow obstruction
What is the most common patient that presents with COPD?
Middle-aged to elderly adult smokers
What causes COPD?
Smoking, previous workplace exposure to dusts and fumes, alpha1-antitrypsin deficiency.
What is the pathology behind COPD?
Inflammation and scarring of small bronchioles causes airflow obstruction.
Describe the pathophysiology of COPD
Lungs hyper inflated with thick mucus in the airways and dilated terminal airspaces.
Emphysema and finely pigmented macrophages in resp. bronchioles
How does COPD present?
Sudden onset of exertion breathlessness on a background of prolonged cough and sputum production.
Dyspnoea, wheeze, cyanosis, cor pulmonale
How is COPD diagnosed?
CXR: hyperinflation, large central PAs CT: bronchial wall thickening, scarring ECG: cor pulmonale ABG: low PaO2 with hypercapnia Spirometry: obstructive
How is COPD managed?
Encourage exercise, diet advice. Smoking cessation. Mucolytics - help chronic productive cough.
SABA/SAMA
FEV1 > 50% LABA
FEV1 <50% LABA plus inhaled corticosteroid in combined inhaler
What can acute COPD exacerbations be triggered by?
Viral/bacterial infections. Common medical emergency in Winter
How do acute COPD exacerbations present?
Increasing cough, breathlessness, wheeze, decreased exercise capacity
How are acute COPD exacerbations managed?
Look for a cause, treat the reversible - controlled oxygen therapy, nebulised bronchodilators (salbutamol), antibiotics
What is asthma?
A chronic inflammatory disorder of large airways characterised by recurrent episodes of reversible airway narrowing
What is the pathology behind asthma?
Atopic individuals respond to allergens - produce large amounts of IgE which bind to the surface of mast cells.
Re-exposure causes degranulation of mast cells, which stimulate airway inflammation and bronchospasm
Inflammation results in hypersensitive reactions
How does asthma present?
Intermittent episodes of breathlessness, wheeze, and chest tightness
Cough, particularly at night
Acid reflux
What are the precipitants of asthma?
Cold air, exercise, emotion, allergens, infection, smoking, NSAIDs, beta blockers
How is asthma diagnosed?
Spirometry, trial on asthma treatment and if successful continue minimum effective dose.
Acute attack: PEF, sputum culture
Chronic: spirometry - obstructive defect, CXR - hyperinflation
How is chronic asthma managed (general)?
Help to quit smoking, avoid precipitants, weight loss, check inhaler technique
How is chronic asthma managed pharmacologically?
Step 1: short-acting inhaled beta2-agonist
Step 2: standard-dose inhaled steroid e.g. beclametasone
Step 3: add long-acting beta2-agonist
Step 4: consider trials of beclametasone/ oral theophylline/ oral leukotriene receptor antagonist
Step 5: add regular oral prednisolone
How does a severe asthma attack present, how is it diagnosed and how is managed?
Acute breathlessness and wheeze
ABG if <92% ox sats
Supplement oxygen, salbumatol 5mg nebuliser with oxygen
What is respiratory failure?
Defined as arterial PO2 <8kPa
What is the difference between type 1 and 2 respiratory failure?
Type 1 - normal or low pCO2
Type 2 - raised pCO2
What can cause type 1 respiratory failure?
Severe pneumonia, pulmonary embolism, acute asthma, pulmonary fibrosis, acute LVF
What can cause type 2 respiratory failure?
COPD, neuromuscular disorders impairing ventilation e.g. myasthenia gravis, reduced respiratory drive e.g. sedative drugs
How are lung carcinomas classified?
Histologically - small cell, non-small cell
NSCLC: Adenocarcinoma, squamous cell carcinoma
How do lung carcinomas present?
Progressive breathlessness, cough, chest pain, hoarseness or loss of voice, weight loss, recurrent pneumonia
How can lung carcinomas metastases present?
Abdominal pain, bony pain, neurological symptoms
What are some extrapulmonary manifestations of bronchial cancer?
Ectopic secretion of ACTH, ADH, PTH Cerebellar degeneration Anaemia Dermatomyositis Clubbing
How are lung carcinomas diagnosed?
CXR: lung collapse, hilar enlargement
Cytology: sputum and pleural fluid
Fine needle aspiration
Lung function tests
What are the risk factors for lung carcinomas?
Cigarette smoking, passive smoking, asbestos, radiation, arsenic
How are non-small cell lung carcinomas managed?
Lobectomy if medically fit and aim is curative intent
Radical radiotherapy
How are small cell lung carcinomas managed?
Chemo, radiotherapy. Consider surgery
SVC stent + radiotherapy and dexamethasone
Analgesia, steroids, anti-emetics
Name 2 benign lung tumours and how they are treated.
Bronchial adenoma
Hamartoma
Surgical excision
What are mesotheliomas?
Malignant tumours arising in the pleura from mesothelial cells
What causes mesotheliomas?
Inhaled asbestos fibres become permanently entrapped in the lung. These become coated with iron, forming asbestos bodies
How do mesotheliomas present?
Breathlessness, chest pain, profound weight loss and malaise
Signs of mets: hepatomegaly, bone pain, abdominal pain
How are mesotheliomas diagnosed?
CXR: pleural thickening/ effusion. Bloody pleural fluid
Diagnosis made on histology (often post-mortem)
How are mesotheliomas managed?
Pemetrexed + cisplatin chemotherapy can improve survival
What is a pulmonary embolism?
Occlusion of a pulmonary artery by an embolic thrombus
What are the risk factors for pulmonary embolisms?
Immobility, recent surgery, malignancy, pregnancy - all cause DVTs which embolise
What causes pulmonary embolisms?
A fragment of a detached thrombus from DVT embolisms via the right side of the heart into the pulmonary arterial circulation and lodges in a pulmonary artery
How do pulmonary embolisms present?
Major PA - instant death - sudden rise in pulmonary arterial pressure, acute RVF, cardiac arrest
Medium PA - breathlessness (V/Q mismatch)
Small PA - breathlessness, chest pain, dizziness
How are pulmonary embolisms diagnosed?
D-dimers, ABG: may show layered PaO2 and PaCO2
Imaging: CXR may be normal
ECG: normal/ tachycardic
How are pulmonary embolisms managed?
Oxygen if hypoxic Morphine IV with anti-emetic if patient is in pain LMW heparin DOAC/ warfarin Thrombolyse massive PE (IV alteplase)
How can pulmonary embolisms be prevented?
Give heparin to all immobile patients
Stop HRT and the combined contraceptive pill pre-op
What organism causes TB?
Mycobacterium tuberculosis - an acid-fast rod-shaped bacillus
How is TB transmitted?
Via inhalation of aerosol droplets containing the bacterium.
What is latent TB?
Infection without disease due to persistent immune system containment.
Positive skin/blood testing shows evidence of infection but patient is asymptomatic and non-infectious
What are the risk factors for the reactivation of TB?
New infection, HIV, organ transplantation, immunosuppression, silicosis, illicit drug use, malnutrition
What patient groups does active disease TB tend to occur in?
Elderly, malnourished, diabetic, immunosuppressed, alcoholic
How does TB present?
Chronic pneumonia with persistent cough, fever, night sweats, weight loss and loss of appetite, malaise, clubbing
How does extra pulmonary TB present?
Meningitis, lymphadenopathy, GU symptoms, bone/joint pain
How is TB diagnosed?
Acid-fast bacilli may be seen in sputum, pleural fluid
CXR: fibronodular opacities in upper lobe
Nucleic acid amplification test
Culture (takes 12 weeks but is definitive)
How is TB managed?
Antibiotics - rifampicin, isoniazid, pyrazinamide, ethambutol