Respiratory Flashcards
What are the surface antigens for influenza A?
- Haemagglutinin
2. Neuraminidase
What is the function of haemagglutinin?
Virus binding and entry to cells
What is the function of neuraminidase?
Cuts newly formed virus loose from infected cells and prevents it clumping together
What causes seasonal epidemics?
Antigenic drift
What causes pandemics?
Antigenic shift
How do new virus strains form?
Genetic reassortment
What are the symptoms of influenza?
- URT symptoms
- LRT symptoms
- Fever
- Headache
- Myalgia
What are the risk factors for influenza mortality?
- Chronic cardiac and pulmonary diseases
- Old age
- Chronic metabolic disease
- Chronic renal disease
- Immunosuppressed
What is the Rx of influenza?
- Oxygen
- Hydration/nutrition
- Tamiflu
What makes pandemics worse?
- More travel
- Bigger population
- Intensive farming
What will make coping with a pandemic better?
- Better nutrition
- Better supportive care
- Vaccination
- Antivirals
How was avian flu controlled?
- Cull affected birds
- Disinfect farms
- Control poultry movement
- Vaccinate workers
What is the Rx for swine flu?
- Oseltamivir
2. Zanamivir
What happens in containment phase?
- Identify cases
- Treat cases
- Contact tracing
- Large scale prophylaxis
What happens in treatment phase?
- Treat cases only
2. National flu pandemic service
What happens in type 1 respiratory failure?
Low PaO2, normal or low PaCO2
What happens in type 2 respiratory failure?
Low PaO2 and raised PaCO2
What can cause raised A-a gradient?
- Diffusion limitation
2. Shunt (right to left)
What is the pathophysiology of high altitude pulmonary oedema?
Exaggerated hypoxic pulmonary vasoconstriction
What is the Rx for high altitude pulmonary oedema?
- Descent
- Oxygen
- Pulmonary vasodilators e.g. nifedipine
What factors determine transfer factor?
- Alveolar volume
- Diffusing capacity of membrane
- Pulmonary capillary blood volume
What does low TLCO indicate?
- Thickening of alveolar-capillary membrane
2. Reduced lung volume
What does high TLCO indicate?
- Increased capillary blood volume
2. Pulmonary haemorrhage
What inhibits O2 transfer in ILD?
Thickening of alveolar layer
What is seen on CT chest in ILD?
Honeycombing
How can ILD be physiologically measured?
- Restricted FVC
- Reduced TLCO
- Hypoxia on exertion
- Reduction in exercise capacity
What is the histology of idiopathic pulmonary fibrosis (IPF)?
- Fibroblastic foci
2. Honeycombing and thickening of alveoli
What is the pathophysiology of IPF?
- Fibroblasts resistant to apoptosis
- Myofibroblasts proliferate and for fibroblastic foci
- Lower GE efficiency in lungs
What is the imaging for IPF?
High resolution CT - honeycombing, traction bronchi
What is the Rx for IPD?
- Pirfenidone
2. Nintedanib
What is the mechanism of action for pirfenidone?
- Inhibits TGF-B
2. Reduces apoptosis of myofibroblasts
What are the SE of pirfenidone?
- Photosensitivity
2. GI upset
What are the SE of nintedanib?
- GI upset
2. Diarrhoea
What type of reaction is hypersensitivity pneumonitis (HP)?
Type III hypersensitivity
Give 3 causes of HP
- Pets
- Mould
- Bird handler
What is the Dx for HP?
- Clinical Hx
- Precipitin IgG level
- Bronchoalveoalr lavage
What is the Rx for HP?
- Avoidance allergen
2. Steroids
What are the symptoms of systemic sclerosis?
- Tightness around mouth
- Calcinosis
- Loss of distal digits
What are the symptoms of cutaneous syndrome of CREST?
- Calcinosis
- Raynaud’s phenomenon
- Oesophageal dysmotility
- Sclerodactyly
- Telangiectasia
What is seen on scans for sarcoidosis?
Honeycombing at base and periphery of lung
What is the Rx for sarcoidosis?
- Immunosuppressants
2. Nintedanib
What is the palliative Rx for ILD?
- Opioids
- Benzodiazepine
- Supplementary O2
What are the symptoms of asthma?
- Cough
- SOB
- Wheezing
- Chest tightness
- Secretions
What is atopy?
Tendency to develop IgE mediated reactions to common aeroallergens
What are the types of asthma?
- Eosinophilic
2. Non-eosinophilic
Why does asthma have diurnal variation?
Natural dip in adrenaline levels
What are the provoking factors for asthma?
- Allergens
- Infections
- Menstrual cycle
- Exercise
- Cold air
How are asthma exacerbations assessed?
- A&E attendance
- GP
- Admissions
- ITU
What problems are associated with asthma?
- Eczema
- Hayfever
- Nasal disease
- Other allergies
- Reflux disease
What are the tests for asthma?
- Eosinophils, SPT, IgE
- CXR
- Skin prick tests
- LFTs
What is present on LFTs in asthma?
- Reduced FEV1
- Reduced FEV1/FVC ratio
- PEFR reductions
- Increased responsiveness to challenge
What is a marker of eosinophilic inflammation?
Exhaled nitric oxide
Who is at risk of asthma death?
- > 3 classes of Rx
- Recent admission
- Previous near fatal
- Brittle disease
- Psychosocial factors
What is the DDx for asthma?
- COPD
- Bronchiectasis
- Bronchial obstruction
- Aspiration
What drugs are available for asthma?
- Bronchodilators e.g. beta agonists
- Steroids
- Omalizumab
- Mepolizumab
What are some SE of oral steroids?
- Hoarse voice
- Oral candida
- Skin thinning
- Osteoporosis
- Adrenal suppression
What is the ladder of asthma Rx?
- Low dose steroids
- Long acting beta agonist
- Lacertine receptor antagonist
- Regular long term oral steroids
What is the Rx for non-eosinophilic asthma?
- Steroids
- Bronchodilator
- Bronchial thermoplasty
What is the initial management for acute asthma?
- High flow O2
- Emergency beta agonists
- Brief Hx
What classifies severe asthma?
- PEFR 33-50%
- RR >25
- HR >110
- Inability to complete sentences
What defines a life threatening asthma attack?
Normal CO2 in acute asthma
What is the Rx for severe asthma?
- O2
- Salbutamol nebuliser
- Prednisolone
- ABGs
What makes up lung immune defence?
- Commensal flora
- Swallowing
- Lung anatomy
- Innate and adaptive immunity
What is the DDx for pneumonia?
- HF
- PE
- Cancer
- TB
- ILD
Which groups are at risk of pneumonia?
- Elderly
- COPD
- Immunocompromised
- Nursing home residents
- DM
What is the pathophysiology of pneumonia?
- Bacteria translocate to sterile airway
- Overwhelm resident host defence
- Develop inflammatory response
- Neutrophils and inflammatory exudate fill alveolar space
What are the symptoms of pneumonia?
- Fever
- Cough
- Sputum
- SOB
- Pleuritic chest pain
What are the signs of pneumonia?
- Raised HR
- Raised RR
- Lung dull to percussion
- Decreased air entry
- Hypoxia
What are the Ix for pneumonia?
- CXR
- FBC
- Biochemistry (LFT, urea)
- CRP
- Pulse oximetry
- Microbiological tests
What can be seen on CXR in pneumonia?
- Air bronchogram
- Interstitial or diffuse shadowing
- Pleural collections
What are the signs of sepsis?
- Delirium
- Renal impairment
- High RR
- Lactic acid production
- BP drop
How is communist acquired pneumonia assessed?
CURB65
What does CURB65 mean?
- Confusion
- Urea >7 mmol/L
- RR > 30
- BP low
- 65+
What are the main pathogens to cause pneumonia?
- S. pneumoniae
- H. influenzae
- S. aureus
- Klebsiella pneumoniae
What Abx are used to treat S. pneumoniae?
- Amoxicillin
- Cefuroxime
- Cefotaxime
What is used to treat pneumonia with abnormal pathogens?
- Erythromycin
- Ciprofloxacin
- Doxycycline
What features are seen in mycoplasma pneumoniae?
- Haemolytic anaemia
- Raynaud’s
- Bullous myringitis
- Encephalitis
What are the extra-pulmonary features in Legionella pneumonia?
- Diarrhoea
- Abnormal LFTs
- Hyponatraemia
- Myalgia
Who is most at risk of Legionella pneumonia?
- Travellers
- Elderly
- Immunocompromised
What is the Ix for pneumonia?
- Sputum culture
- Serology
- Urinary antigen
- PCR
- Blood culture
What is the prevention for pneumonia?
- Vaccine against pneumococcal disease, influenza
2. Smoking cessation
What are the signs of empyema?
- Failure of fever to settle on Abx
- Pain on deep inspiration
- Signs of pleural collection
What is the Ix for parapneumonic effusion?
Thoracentesis
What is the Rx for empyema?
- Chest drainage
2. Co-amoxiclav
Which groups is lung abscess more common in?
- Aspiration
- Alcoholics
- Poor dentition
Who is at risk of hospital acquired pneumonia?
- Elderly
- Ventilator assisted
- Post-operative
What is the Dx for hospital acquired pneumonia?
- New infection
- Purulent secretions
- New radiological infiltrates
- New CRP increase
- Increased O2 requirements
What are the Abx for hospital acquired pneumonia?
- Piperacillin-tazobactam
- Linezolid or vancomycin
- Colistin
What causes most bronchiolitis?
Respiratory syncytial virus (RSV)
What is the pathophysiology of bronchiolitis?
Inflammation of bronchioles and mucus production cause airway obstruction
What are the symptoms of bronchitis?
- Cough
- Phlegm
- Breathlessness
- Wheeze
What is the pathophysiology of bronchitis?
Self-limited inflammation of epithelia of bronchi due to URI
What distinguishes chronic bronchitis?
COPD pt. with cough for at least 3 months in each of 2 successive years
What are the Ix for bronchitis?
- CXR normal
- Throat swabs
- Serology