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