Describe pneumothorax
Presences of air in the pleural space causing partial or total lung collapse, categorised as…
- primary: spontaneous with no underlying lung disease, rupture of subdural blebs, common in tall thin men
- secondary: spontaneous with known lung disease (e.g. asthma, COPD, ILD, CF), infection (TB, PCP), or trauma
- iatrogenic: risk with central line/pacemaker insertion, mechanical ventilation, lung biopsies
What are the clinical features of a pneumothorax?
- Pleuritic chest pain
- Dyspnoea
- Tachypnoea
- Tachycardia
- Hypotension
- Hypoxia
- Examination: reduced breath sounds, hyper resonant percussion, decreased chest wall movement
- Tension pneumothorax: severe respiratory distress, tracheal deviation, jugular vein distention, haemodynamically unstable
What is the management of pneumothorax?
- Confirm diagnosis on CXR (or bedside ultrasound in emergencies)
- Conservative management if <2cm
- Chest drain if high-risk characteristics (haemodynamically unstable, bilateral pneumothorax, significant hypoxia, >50 with significant smoking history, underlying lung disease)
- If low-risk characteristics: either conservative, outpatient ambulatory pleural vent device, needle aspiration, or chest drain
- For recurrent cases: video-assisted thoracoscopic surgery for pleurodesis
Describe the features of a chest drain?
- Inserted into the ‘triangle of safety’: 5th intercostal space, between the mid and anterior axillary line
- Air from the pneumothorax will drain into water, causing bubbling
- The drain should be “swinging” as the water level rises and falls with breathing
- Complications: air leaks around drain site (continuous bubbling of water), and surgical emphysema (air collects in the subcutaneous tissue)
Describe pleural effusion
Collection of fluid in the pleural space, classified as…
- exudates: high protein content (>30g/L)
- transudates: low protein content (<30g/L)
What are the causes of a pleural effusion?
Exudates:
- infection (pneumonia, TB)
- malignancy (lung cancer, mesothelioma, metastases)
- PE
- pancreatitis
- inflammatory disorders (RA, SLE)
Transudates:
- heart failure
- hypoalbuminaemia (liver disease, nephrotic syndrome, malnutrition)
- hypothyroidism
- Meigs’ syndrome (ovarian tumour, ascites, pleural effusion)
What are the clinical features of a pleural effusion?
- Shortness of breath
- Cough
- Chest pain
- Examination: reduced breath sounds, dull percussion, tracheal deviation away from large effusions
What investigations are needed for a pleural effusion?
- CXR: blunting of costophrenic angles, fluid in lung fissures, etc.
- US or CT: identifies smaller effusions
- Pleural fluid analysis: measure protein content, LDH, Ph, glucose, and microbiology
What is the management of a pleural effusion?
- Treatment of underlying cause
- Conservative management if small
- Drainage of fluid: pleural aspiration for temporary relief, or chest drain
- For recurrent effusions: pleurodesis (uses talc to may pleura more adhesive)
Describe empyema
- Infected pleural effusion or pus in the pleural space
- Presentation: resolving pneumonia but new or persistent fevers
- Investigations: CXR, pleural aspiration (pus, low pH, low glucose, high LDH)
- Management: chest drain, antibiotics
Describe COPD
Chronic obstructive pulmonary disease, characterised by chronic bronchitis (inflammation of bronchi), emphysema (damage and dilatation of alveolar sacs), and airway obstruction, with incidence increasing with age and strongly linked with smoking
What are the risk factors for COPD?
- Cigarette smoking
- Occupational exposures (e.g. dust, vapours, fumes, chemicals, biomass smoke)
- Air pollution
- Abnormal lung development (bronchopulmonary dysplasia)
What are the clinical features of COPD?
- Shortness of breath
- Persistent cough
- Wheeze
- Sputum production
- Recurrent respiratory infections
- If severe: right sided heart failure/cor pulmonale (raised JVP, peripheral oedema, murmurs)
What investigations are needed for COPD?
- Spirometry: FEV1/FVC <0.7 (confirms obstruction), with no reversibility, FEV1 grades severity (>80% = mild, 50-80% = moderate, 30-50% = severe, <30% = very severe)
- CXR: may show hyperinflation or other causes
- High resolution CT: sensitive in detecting emphysema and bronchiectasis
- Echo: assess right heart function
- Sputum culture: if suspecting infection
- Serum alpha-1 antitrypsin: check for deficiency
- FBC: polycythaemia in chronic hypoxaemia
What is the long-term management of COPD?
Non-pharmacological:
- smoking cessation
- pneumococcal and flu vaccines
- pulmonary rehabilitation
Pharmacological:
- 1st line: SABA or SAMA as reliever
- 2nd line if no asthmatic features: add regular LABA + LAMA
- 3rd line if asthmatic features (e.g. previous asthma/atopy, diurnal variation, raised eosinophils): LABA + LAMA + ICS
- 4th line specialist options: nebulisers, mucolytics, prophylactic azithromycin, oral corticosteroids, theophylline
Long-term oxygen therapy:
- used if very severe obstruction (FEV1 <30% predicted) chronic hypoxia, polycythaemia, cyanosis, or cor pulmonale
- cannot be used if still smoking
What are the causes of an acute exacerbation of COPD?
- Bacterial infections (e.g. strep pneumoniae, H. influenzae, Moraxella catarrhalis, mycoplasma pneumoniae)
- Viral infections (e.g. rhinovirus, influenza, coronavirus, RSV)
- Indoor and outdoor air pollutants
- Allergens
- Medication non-compliance
What are the clinical features of an acute exacerbation of COPD?
- Dyspnoea (worse than baseline)
- Increased sputum volume and purulence
- Increased respiratory effort (tachypnoea, use of accessory muscles, nasal flaring)
- Worsening signs on examination (prolonged expiratory wheeze, reduced breath sounds, crackles)
- New or worsening hypoxia and/or hypercapnia
- Confusion or altered consciousness
What investigations are needed for an acute exacerbation of COPD?
- ABG: typically causes respiratory acidosis and type 2 respiratory failure (low pH, low pO2, raised CO2, raised bicarb)
- CXR: may show consolidation with infection
- FBC: raised WCC
- Sputum and blood cultures
What is the management of an acute exacerbation of COPD?
Medical management:
- regular inhaled and/or nebulised salbutamol or ipratropium
- steroids (5 day course of prednisolone)
- antibiotics (e.g. amoxicillin/doxycycline depending on local guidelines)
- IV aminophylline
Respiratory support:
- target saturation of 88-92% (unless normal pCO2 and pH on ABG)
- 1-2L via nasal cannula
- 24-28% Venturi mask
- non invasive ventilation (if pH<7.35), contraindicated in untreated pneumothorax)
- invasive ventilation (if pH<7.25)
Describe asthma COPD overlap syndrome
- Persistent airflow obstruction with increased reversibility, response to inhaled corticosteroids, and eosinophilic inflammation, common in smokers and history of asthma
- Presentation: persistent, progressive, or recurrent dyspnoea, wheeze, cough, chest tightness, with frequent exacerbations
- Management: stop smoking, SABA for reliever, regular LABA + ICS, add on LAMA if uncontrolled
Describe the pathophysiology of asthma
Chronic inflammatory air way disease, characterised by…
- airway inflammation: activation of immune cells in response to various triggers, resulting in release of inflammatory mediators (IgE dependent)
- bronchoconstriction: smooth muscle contraction, triggered by inflammatory mediators, reversible with bronchodilators
- airway hyper-responsiveness: inhaled stimuli cause exaggerated airway narrowing and inflammatory response
- mucus production and airway remodelling: as a result of chronic inflammation
What are the typical triggers for asthma?
- Viral infections
- Exercise
- Allergens (animals, house dust mites, pollen, moulds, food)
- Cold or damp air
- Air pollution
- Tobacco smoke
- Strong emotions
- Medications: beta-blockers, NSAIDs
What are the clinical features of asthma?
- Wheeze
- Cough
- Dyspnoea
- Chest tightness
- History of atopy
- symptoms are episodic, have diurnal variation, and triggered by allergens, cold, exercise etc.
What investigations are needed for asthma in adults?
- FeNO test: >50
- Eosinophils: raised
- Spirometry: FEV1/FVC < 0.7 (obstructive), FEV1 increase of >200ml/>12% after bronchodilator (reversable)
- Peak flow: diurnal variation of >20%
- Direct bronchial challenge test: airway hypersensitivity causes bronchoconstriction in response to methacholine/histamine (>20% reduction in FEV1)
