Resp: Asthma, COPD, Brochiestasis, CF Flashcards
What is Asthma?
A chronic inflammatory disorder of the airways
What are the defining characteristics of asthma?
- Susceptibility
- Variable airflow obstruction
- Chronic inflammatory process
- Reversibility
- Airway hyperreposniveness
What are the symptoms of asthma?
- Expiratory wheeze
- Cough
- Difficulty breathing
- Chest tightness
- Exercise induced wheeze
- Atopic history (allergies)
What differentiates asthma and COPD?
- Airway obstruction in asthma is often reversible with bronchodilators(>15% improvement with treatment)
- Airway obstruction in COPD is not fully reversible (<15% improvement with treatment)
What should an asthma diagnoses be made on?
- History of characteristic symptom patterns
- Evidence of variable airflow limitation, from bronchodilator reversibility testing or other tests
What present with a severe asthma exacerbation?
Silent chest
What is the frequent finding on physical examination of asthmatic patient?
- Often normal
- Wheezing may be absent during severe asthma exacerbation
What are common triggers for asthma?
- Allergens
- Cold air
- Exercise
- Fumes
- Cigarette smoke
- Perfumes
- Chemicals
- Drugs
- Emotional distress
What cells primarily drive asthma?
TH2 cells
What are the main points in the pathophysiology of asthma?
- Presentation of antigen to T lymphocytes
- TH2 release cytokines which attract and activate inflammation cells including mast cells and eosinophils
- Activation of B cells occurs as well which produce IgE
- In a sensitised atopic asthmatic exposure to antigen results in a 2 phase response.
- Immediate response and late phase response
What is the immediate response for asthma pathophysiology?
- Interaction of allergen and specific IgE antibodies
- Leads to mast cells
What is the late phase response?
- Type 4 hypersensitivity
- Involves inflammatory cells including eosinophils, mast cells, lymphocytes and neutrophils which release mediators and cytokines
- This causes airway inflammation
What is the result inflammatory cells in asthma on the bronchioles?
- Reduced airway calibre
- Mucosal swelling (oedema) due to vascular leak
- Thickening of bronchails wall due to inflammatory cell infiltration
- Mucus overproduction (sticky, thick, tenacious)
- Smooth muscle contraction
- Epithelium shed and incorporated into thick mucus
- Hyper responsiveness of the airway
What are the effect of long term poorly controlled asthma on the respiratory organs?
- Hypertrophy and hyperplasia of smooth muscle
- Hypertrophy of muccus glands
- Thickening of the basement membrane
What type of respiratory failure normally occurs in severe asthma attacks?
- Type 2 respiratory failure
- Hyperventilation cannot compensate due to extensive effect
What type of respiratory failure occurs in mild asthma?
- Type 1 respiratory failure
- Compensation of hyperventilation
What test are used to assess the condition of a patient with suspected asthma?
Airflow limitation - FEV1/FVC reduced
Variation in lung function greater than normal
Spirometry
How can eosinophilic inflammation be measured?
- Induced sputum
- Peripheral eosinophil count
- FeNO
What are the principles of asthma treatment?
- Patient education (SIMPLE)
- Drug treatment involves brochodilators (beta2) and steroids such as prednisone . Inhalers are used to deliver in aerosol form.
- Long acting reliever is prescribed with corticosteroid inhaler. B2 agonist is also given
How do we treat acute severe asthma?
- Oxygen, high flow –aim to keep O2 94-98% sat
- Nebulised salbutamol
- Oral prednisolone
- If moderate exacerbation not responding, or acute severe/life threatening, add nebulised ipratropium bromide
- Consider iv magnesium and/or iv aminophylline if no improvement and life-threatening features not responding to above treatment
What are the characterises of acute severe asthma?
- Respiratory rate >25
- Heart rate >110/min
- Inability to complete sentences in one breath
What are the features of life threatening asthma?
- Altered conscious level
- Exhaustion
- Arrthymia
- Hypotension
- Cyanosis
- Silent chest
- Poor respiratory effort
- PEF <33% best or predicted
- SpO2 <92%
- PaO2 <8 kPa
- Normal PaCO2
What is COPD?
A disease state characterised by airflow limitation that is not fully reversible. It encompasses both emphysema and chronic bronchitis.
What is the aetiology of COPD?
- Tobacco (90% of cases)
- Air pollution
- Occupational exposure
- Alpha-1 antitrypsin deficiency
What are the pathological changes in COPD?
- Enlargement of mucus-secreting glands of the central airways
- Increased number of goblet cells (which replace ciliated respiratory epithelium)
- Ciliary dysfunction
- Breakdown of elastin leading to destruction of alveolar walls and structure, and loss of elastic recoil.
- Formation of larger air spaces with reduction in total surface area available for gas exchange
- Vascular bed changes leading to pulmonary hypertension.
What are the effects of the pathological changes in COPD?
-Progressive hypoxia leading to Cor Pulmonale
What is the pathophysiology of the COPD?
- Host repose to to inhaled cigarette or other noxious substances
- Chronic inflammation process and oxidative injury which affects central and peripheral airways, lung parenchyma, alveoli and pulmonary vasculature.
What are the symptoms of COPD?
- Cough that is productive of sputum
- Shortness of breath initially on exertion but can progress to at rest
What are the sign of COPD on physical examination?
- Tachypnoea
- Use of accessory muscles of respiration
- Barrel chest
- Hyper resonance on percussion
- Reduced intensity breath sounds
- Wheezing may be present
What are some late features of COPD?
- Central cyanosis
- Flapping tremors
- Signs of right sided heart failure second to pulmonary hypertension
What the specific features of emphysema?
- Elastin breakdown
- Loss of alveolar integrity
- Permanent destructive enlargement of the airspaces distal to terminal bronchioles
What are the specific feature of chronic bronchitis?
- Excessive mucus secretion
- Impaired removal of section due to ciliary dysfunction
- Chronic productive cough
- Chronic respiratory infections
What are some lung function tests in COPD?
- Spirometry (FEV1/FVC <70%)
- Chest X-ray show hyper inflated lungs
- Pulse oximetry
- ABG analysis
- Alpha-1 antitrypsin level checked
What is the management of COPD?
- Smoking cassation
- Bronochdilatos
- Pulmonary rehabilitation
- Long term oxygen management
- Surgical interventions
What vaccinations are recommended for COPD patients?
Pneumococcal vaccinations
How are patient with acute exacerbations of COPD managed?
- Montor for hypoxia and hypercapnia
- Appropriate antibiotics to account for pneumococcus and haemophilia influenza
- Nebulised bronchodilators
- Oral steroids
- 24 or 28% oxygen therapy
What are the complications of COPD?
- Recurrent pneumonia
- Pneumothorax
- Respiratory failure
- Cor Pulmonale
What is bronchiestasis?
Bronchiectasis is the Chronic dilatation of one or more bronchi. The bronchi exhibit poor mucus clearance and there is predisposition to recurrent or chronic bacterial infection
What is the Gold standard diagnostic test for bronchiestasis?
High resolution CT
What are the symptoms of bronchiectasis?
- Chronic cough
- Daily sputum production
- Breathless on exertion
- Intermittent haemopytisis
- Nasal symtoms
- Chest pain
- Fatigue
What is the pathophysiology of bronchiestasis?
- Post infective
- Immune deficiency
- Genetic/Mucocilliary clearance defect
- Obstruction
- Toxic insult
What are the common organisms to cause bronchiestasis?
- Haemophilus influenza
- Pseudomonas aeruginosa
- Moraxella catarrhalis
- Stenotrophomonas maltophilia
- Fungi (aspergillus, candida)
- Non-tuberculous mycobacteria
- Staph aureus (think about CF)
What is the management for bronchiestasis?
- Treat underlying cause
- Physiotherapy
- Antibiotics according to sputum cultures
- Supportive
- Pulmonary rehabilitation
- Management plan for infective exarcerbations
What is Cystic fibrosis?
CF is an autosomal recessive disease leading to mutations in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR).
-No longer able to push chloride out of the cells
What is the pathophysiology and organs affected in Cystic fibrosis?
- Chromosome 7 defect
- Leads to Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) mutation
- Leads to ineffective cell surface chloride transport
- Leads to thick, dehydrated body fluids in organs which have CFTR (Mucus)
- Affects Pancreas, Skin, GI tract, Vas deferens, Lungs, Reproductive Organs.
What are the presentations of CF?
- Meconium Ileus (delay in passing first stool)
- Intestinal malabsorption
- Recurrent chest infections
- Newborn screening
How is CF diagnosis made?
A history of CF in a sibling
Or a positive newborn screening test result
And
-An increased sweat chloride concentration
(> 60 mmol/l) – SWEAT TEST
-Or identification of two CF mutations – genotyping
-Or demonstration of abnormal nasal epithelial ion transport (nasal potential difference)
What is the management of CF?
- Agressive therapy with respiratory infections with physio and antibiotics
- Monitoring of body weight
- Pancreatic enzyme supplements (Can present with distal intestinal obstruction syndrome)
How does distal intestinal obstruction syndrome present?
-Palpable right iliac fossa mass
Examples of lifestyle advice for CF patients
- No smoking
- Avoid other CF patients
- Avoid friends / relatives with colds / infections
- Avoid Jacuzzis (pseudomonas)
- Clean and dry nebulisers thoroughly
- Avoid stables, compost or rotting vegetation – risk of aspergillus fumigatus inhalation
- Annual influenza immunisation
- Sodium chloride tablets in hot weather/vigorous exercise
