Respiratory Flashcards
What are the causes of Asthma? (3)
Caused by a Reversible airway obstruction
Cause unknown exactly- combination of:
Environmental factors
Genetic factors
What 3 factors contribute to airway narrowing in Asthma? (3)
Bronchial muscle contraction (triggered by variety of stimuli)
Mucosal swelling/inflammation (caused by mast cell and basophil degranulation resulting in the release of inflammatory mediators)
Increased mucus production
What are the risk factors for Asthma? (7)
Gender (male more likely than female) Family History Atopic allergies (eczema/hayfever) Smoking Obesity Viral respiratory infections in infancy and childhood Air pollution
What are the symptoms of Asthma? (4)
Intermittent dyspnoea
Wheeze
Cough (often nocturnal)
Sputum
What are the signs of Asthma on examination? (6)
Tachypnoea Audible wheeze Hyperinflated chest Hyper resonant percussion note Decreased air entry Polyphonic wheeze
What are the possible differential diagnoses of Asthma? (4)
COPD
Pulmonary oedema
Large airway obstruction
Superior Vena Cava obstruction
What investigations could be done to diagnose Asthma? (4)
Peak expiratory flow
Sputum culture
Blood tests (FBC, U&Es, CRP, cultures)
ABG (showing normal/slightly low PaO2 and low PaCO2 due to hyperventilation)
What drugs can be used to treat Asthma?
- B2-adrenoreceptor agonists (relax bronchial smooth muscle by increasing cAMP, act in minutes, eg Salbutamol)
- Corticosteroids (⬇️ bronchial mucosal inflammation, act over days, eg beclometasone)
- Aminophylline (inhibits phosphodiesterase, thus ⬇️ bronchoconstriction by ⬆️ cAMP)
- Anticholinergics (⬇️ muscle spasm synergistically with B2 agonists, eg ipratropium)
- Leukotriene receptor antagonists (block the effects of cysteinyl leukotrienes in the airways by antagonising the CystLT1 receptor, eg montelukast)
- Anti-IgE monoclonal antibody (used in persistent allergic asthma, eg omalizumab)
How common is COPD?
Affects 10-20% of >40s
What is COPD?
COPD is a common progressive disorder characterised by airway obstruction with little or no reversibility.
It includes chronic bronchitis and emphysema.
What is a “pink puffer” and a “blue bloater”?
PINK PUFFER: have increased alveolar ventilation, normal PaO2 and low/normal PaCO2. They are breathless but not cyanosed. They may progress to T1 Respiratory failure.
BLUE BLOATER: have decreased alveolar ventilation, low PaO2 and high PaCO2. They are cyanosed but not breathless. They may go on to develop cor pulmonale. Their respiratory centres are relatively insensitive to CO2. They rely on hypoxic drive to maintain respiratory effort. (Therefore O2 given with care).
What causes COPD?
Smoking
The lining of the lungs becoming inflamed which can lead to scarring. This can be caused by smoking and exposure to smoke and air pollution.
Alpha-1 antitrypsin deficiency can cause COPD as if there is a deficiency in A1AT then elastase breaks down elastin and in the lungs this leads to the destruction of alveolar walls and emphysematous change. Smoking can accelerate this very quickly.
What are the risk factors for COPD?
Smoking
Air pollution
Occupation (dusts, chemicals, vapours, irritants, fuels)
Frequent LRTIs in childhood
What are the symptoms of COPD? (4)
Cough
Sputum
Dyspnoea
Wheeze
What are the signs of COPD on examination? (10)
Tachypnoea
Use of accessory muscles during respiration
Hyperinflation
Decreased cricosternal distance (
What are the possible differential diagnoses of COPD? (6)
Asthma Bronchiectasis CCF Lung cancer Obliterative bronchiolitis Bronchopulmonary dysplasia
What investigations are necessary to diagnose COPD? (2)
Spirometry
- Mild (stage 1) COPD is FEV1 at least 80% of predicted value
- Moderate (stage 2) COPD is FEV1 between 50% and 79% of predicted value
- Severe (stage 3) COPD is FEV1 between 30% and 49% of predicted value
- Very severe (stage 4) COPD is FEV1 of less than 30% of predicted value
Chest X-Ray (necessary to exclude other diagnoses)
What are the possible treatments of COPD?
General
- smoking cessation
- encourage exercise
- diet (treat poor nutrition or obesity)
- influenza & pneumococcal vaccinatio
- pulmonary rehabilitation
- PRN short acting antimuscarinics (ipratropium) or B2 agonist (salmeterol)
Mild/moderate
- inhaled long-acting antimuscarinic (tiotropium) or B2 agonist
Severe
- Combination long-acting B2 agonist & corticosteroids
How common is Bronchial Carcinoma?
Approximately 95% of all primary lung tumours are bronchial carcinomas
Bronchial carcinomas account for approximately 19% of all cancers
Who does Bronchial carcinoma affect?
Mostly affects smokers
What are the risk factors for Bronchial Carcinoma? (6)
Smoking
Increased age
COPD
Past history of head and neck cancer
Industrial dust diseases, asbestos, chromium, arsenic, iron oxide, radiation
Epidermal growth factor receptor tyrosine kinase (EGFR-TK) mutation
What are the symptoms of Bronchial Carcinoma? (8)
Cough Haemoptysis Dyspnoea Chest pain Recurrent/slowly resolving pneumonia Lethargy Anorexia Weight loss
What are the signs of Bronchial Carcinoma on examination? (3)
General signs: Cachexia Anaemia Clubbing Hypertrophic pulmonary osteoarthropathy (HPOA) Supraclavicular or axillary nodes
Chest signs: None Consolidation Collapse Pleural effusion
Metastases: Bone tenderness Hepatomegaly Confusion Fits Focal CNS signs Cerebellar syndrome Proximal myopathy Peripheral neuropathy
What are the possible differential diagnoses of Bronchial Carcinoma? (10)
Secondary malignancy Arteriovenous malformation Pulmonary hamartoma Bronchial adenoma Abscesses Granuloma Encysted effusion Cyst Foreign body Skin tumour
What investigations are necessary to diagnose Bronchial carcinoma? (5)
Cytology - sputum and pleural fluid Chest X-Ray: - peripheral nodule - hilar enlargement - consolidation - lung collapse - pleural effusion - bony secondaries
Bronchoscopy
CT - to stage the tumour
PET scan
What are the treatments for Bronchial Carcinoma? (4)
Non-small cell:
- Excision
- Curative radiotherapy
- Chemotherapy +/- radiotherapy
Small cell
- almost always disseminated at presentation
- may respond to chemo but will invariably relapse
- palliative radiotherapy
- analgesic drugs
What are the types of pneumothorax? (3)
Primary spontaneous pneumothorax - pneumothorax occurring in healthy people
Secondary spontaneous pneumothorax - associated with underlying lung disease, worse consequences
Tension pneumothorax - MEDICAL EMERGENCY!!
How common is a pneumothorax?
PSP - 24/100,000/year in males
- 9.9/100,000/year in females
Who does pneumothorax affect?
Young, tall, thin, males People with other lung diseases - Asthma - COPD - Cystic Fibrosis - Tuberculosis - Whooping cough
PSP occurs most often in the 20s and rarely over age of 40
SSP typically occurs between 60-65
What causes a pneumothorax?
Spontaneous due to rupture of sub-pleural bulla
Lung diseases:
- asthma
- COPD
- TB
- pneumonia
- CF
- lung fibrosis
- sarcoidosis
Connective tissue disorders
Trauma
Iatrogenic
What are the risk factors for pneumothorax?
Tall, young, thin males
Smoking
Family history of pneumothorax
Underlying lung conditions
What are the symptoms of a pneumothorax? (4)
Sudden onset dyspnoea
Pleuritic chest pain
Pts with asthma/COPD may present with sudden deterioration
May be asymptomatic
What are the signs of a pneumothorax on examination? (4)
Reduce chest expansion unilaterally
Hyper-resonance on percussion
Reduced breath sounds unilaterally
Deviated trachea
What are the possible differential diagnoses of a pneumothorax? (3)
Pleural effusion- tends to be slower onset and there is dullness on percussion
Chest pain: a pleuritic pain may give sensation of breathlessness
Pulmonary Embolism - may produce haemoptysis and more commonly affects lower lungs
What investigations are necessary to diagnose pneumothorax? (4)
Chest X-Ray
Ultrasound
CT
ABG - show hypoxia
What are the treatments for a pneumothorax?
PSP
- aspiration
- observe
SSP
- supplementary O2 as relieves hypoxia and accelerates reabsorption of the pneumothorax compared to breathing air
- most pts will need chest drain
- If persistent air leak then pt needs referring to thoracic surgeons
What is a pleural effusion?
Fluid in the pleural space
How can you divide pleural effusions and what is the difference?
By their protein concentrations:
- Transudates (35g/L)
Examples:
Haemothorax= blood in pleural space
Empyema= pus in pleural space
Chylothorax = lymph (with fat) in the pleural space
Haemopneumothorax= blood and air in pleural space
What causes pleural effusion?
Transudates: May be due to ⬆️ venous pressure -cardiac failure -constrictive pericarditis -fluid overload Hypoproteinaemia -cirrhosis -nephrotic syndrome -malabsorption
Exudates:
Mostly due to ⬆️ leakiness of pleural capillaries secondary to:
-infection (pneumonia)
-inflammation
-malignancy (most commonly lung and breast cancer)
What are the symptoms of pleural effusion? (3)
Asymptomatic
Dyspnoea
Pleuritic chest pain
What are the signs of pleural effusion on examination? (6)
Decreased chest expansion
Stony dull percussion note
Reduced breath sounds on affected side
Tactile vocal fremitus and vocal resonance are decreased.
Bronchial breathing may be present above effusion where lung is compressed
Tracheal deviation away from effusion in large pleural effusions
What are the possible differential diagnoses of pleural effusion?
Transudates: CCF Cirrhosis with hepatic hydrothorax Nephrotic syndrome Hypoproteinaemia Glomerulonephrotis SVC obstruction CSF leak to pleural space
Exudates: Malignancy Pneumonia Tuberculosis PE Fungal infection
What tests are necessary to diagnose pleural effusion? (4)
Chest X-Ray
- small effusions blunt costophrenic angles
- large effusions seen as water dense shadows with concave upper borders
Ultrasound
Diagnostic aspiration
Pleural biopsy
How do you treat/manage pleural effusion?
Drainage
What are the two classifications of pneumonia? (2)
Lobar pneumonia
- form of pneumonia infection that only involves a single lobe of the lung
- often due to streptococcus pneumoniae
Bronchopneumonia
How common is CAP?
0.5-1% in UK every year
What causes lobar pneumonia?
Most often streptococcus pneumoniae
Other causes:
Haemophilus influemzae
Moraxella catarrhalis
Mycobacterium tuberculosis
What are the risk factors for lobar pneumonia?
Age - young children and elderly
Lifestyle - smoking and alcohol
Preceding viral infections - eg influenza predisposing to streptococcus pneumoniae infection
Immunosuppression
IV drug abuse - associated with staph aureus infection
Hospitalisation - often with Gram -ve organisms
Underlying predisposing disease - DM, cardiovascular disease
What are the symptoms of lobar pneumonia?
Fever Rigor Malaise Anorexia Dyspnoea Cough Purulent sputum Haemoptysis Pleuritic pain
What are the signs of lobar pneumonia on examination?
Pyrexia Cyanosis Confusion Tachypnoea Tachycardia Hypotension Signs of lung consolidation: - diminished chest expansion - dull percussion note - increased tactile vocal fremitus/resonance - bronchial breathing Pleural rub
What are the possible differential diagnoses of lobar pneumonia?
Pulmonary oedema Pleural effusion Pneumothorax PE Asthma COPD Bronchiectasis Fibrosing alveolitis Neoplasm Sarcoidosis
What investigations would you do to diagnose lobar pneumonia?
Chest X-Ray
SpO2
ABG
BP
Blood tests- FBC, U&Es, CRP, LFT, blood cultures
Sputum microscopy and culture
Aim to identify pathogen and assess severity
CURB 65 scoring system
What is the CURB 65 scoring system for pneumonia?
C - confusion
U- urea >7mmol/L
R - respiratory rate >/= 30 breaths/min
B - Blood pressure (65 years
How do you manage a pt with lobar pneumonia?
Antibiotics (mild-mod= amoxicillin OR clarythromycin severe= co-amoxiclav OR Cephalosporin e.g. Cefuroxime )
- Oxygen - keep PaO2 >8 and SpO2 >94%
- IV fluids and VTE prophylaxis
- Analgesia for pleuritic pain
How common is a PE?
1/1000 people/year have a DVT
If untreated about 1/10 people with a DVT will develop a PE
What causes PE?
Results from obstruction within pulmonary arterial tree
Emboli can be caused by:
- thrombosis (DVT - causes most PEs)
- fat
- amniotic fluid
- air
What are the risk factors for a PE?
Surgery Obstetrics Lower limb problems Malignancy Reduced mobility Previous venous thromboembolism
What are the symptoms of a PE?
Dyspnoea
Pleuritic chest pain (sharp stabbing pain when breathing in)
Retrosternal chest pain
Cough
Haemoptysis
Any chest symptoms in a pt with symptoms suggesting a DVT
What are the signs of PE on examination?
Tachypnoea
Tachycardia
Hypoxia - leading to anxiety, restlessness, agitation and impaired consciousness
Pyrexia
Elevated JVP
Galloping heart rhythm, widely split heart sounds, tricuspid regurg murmur
Pleural rub
Systemic hypertension and cardiogenic shock
What are the possible differential diagnoses of PE?
Other causes of collapse, chest pain or dyspnoea:
Acute coronary syndromes Aortic dissection Cardiac tamponade Pneumonia Pneumothorax Sepsis
What investigations are necessary to diagnose a PE?
Baseline obs: O2 sats, FBC, biochem, clotting screen
ECG
Chest X-Ray
ABG - may show reduced PaO2 and PaCO2 due to hyperventilation
Echocardiogram
Cardiac troponins
D-dimers- fibrin D-dimer is a degradation product of cross-linked fibrin, conc increases in patients with acute VTE and provides a very sensitive test to exclude acute DVT or PE
Specific investigations for VTE: Coronary angiography Leg ultrasound Isotope lung scanning CPTA
What are the treatments of PE?
Anticoagulation therapy:
Starts as soon as PE is suspected
Medications or tablets
Low molecular weight heparins
In pregnant women regular heparin instead or warfarin
What are the causes of pulmonary fibrosis?
Replacement fibrosis secondary to lung damage
Extrinsic allergic alveolitis (bird fanciers lung)
Granulomatous diseases eg sarcoidosis
Radiation exposure
What are the risk factors of pulmonary fibrosis?
Drugs and environmental causes Smoking GORD Infectious agents Genetic factors
What are the symptoms of pulmonary fibrosis?
Gradual onset of SOB
Chronic non productive cough
Wheezing
Haemoptysis
Chest pain
Non-specific fever, myalgia
Finger clubbing
What is the treatment for pulmonary fibrosis?
Smoking cessation Avoidance of other cause Influenza and pneumococcal vaccination O2 therapy for significant hyperaemia Immunosuppressive therapy
How common is Asthma? (3)
Affects 5-8% of population
3rd most common Hospital Admission in children
5-10% of adults have severe asthma
Define type 1 respiratory failure
PaO2 ⬇️
PaCO2 normal
Define type 2 respiratory failure
PaO2 ⬇️
PaCO2 ⬆️
What organism causes cavitating pneumonia ?
Klebsiella
Local complications of bronchial carcinoma ?
- recurrent laryngeal nerve palsy
- phrenic nerve palsy
- SVC obstruction
- horners syndrome (pancoasts tumour)
- rib erosion
- pericarditis
Causes of type 1 respiratory failure
V/Q mismatch:
- pneumonia
- pul oedema
- PE
- asthma
- emphysema
- pulmonary fibrosis
Causes of type 2 respiratory failure ?
Alveolar hypoventilation with or without v/q mismatch
- pul disea: COPD, obstructive sleep apnoea, asthma
- reduced respiratory drive: sedatives, CNS tumour
- neuro muscular disease: myasthenia gravis, G-B
- thoracic wall disease: flail chest, kyphoscoliosis
When to consider ABG ?
- any unexpected deterioration in ill patient
- acute exacerbations of chronic chest conditions
- impaired consciousness or impaired resp effort
- signs if co2 retention
- cyanosis, confusion
