Chest Medicine Flashcards
Airway diseases (3)
COPD, Asthma, Bronchiectasis
Respiratory Diseases of the PARENCHYMA/ INTERSTITIUM (4)
Fibrosis, Hypersensitivity Pneumonitis,
Emphysema, pneumonia
Respiratory Diseases of the Pluera
Pleural Effusion, Pleural thickening, Mesothelioma/Pleural malignancy
Vascular problems
PE, Pulmonary hypertension
Ventilation problems
Sleep disordered breathing, obesity hypoventilation, neuromuscular problems, thoracic cage abnormality
Imaging for lung diseases
CXR, HRCT,
Pulmonary function tests
Spirometry – FEV1/ VC/ FVC/ FEV1/VC ratio
Lung volumes – TLC/ RV
Transfer factor – TLCO/ KCO
Restrictive lung diseases
Normal FEV1/VC
Obesity, Thoracic cage abnormalities, fibrosis, neuromuscular abnormalities
Obstructive lung diseases
FEV1/VC <70%
Asthma
COPD
Bronchiectasis
Flow Volume loops
Can show if airflow is appropriate for a particular lung volume. Can give an indication of where major problem is.
Large airway obstruction- flattened exp and inspir loop,
Diffuse small airway obstruction- early peaked exp loop and normal inspir loop
Intrathoracic obstruction (mediastinal tumour) have a more pronounced affect on the expiratory than inspiratory limb
Extrathorcic obstruction (goiter) has a more pronounced affect on the inspiratory than expiratory limb
Lung volumes TLC & RV- Obstructive
TLC increases with hyperinflation, RV increases due to gas trapping
Lung volumes TLC & RV- Restrictive
TLC- reduced
RV- normal/low
Test of functionality of the alveolar-capillary membrane
Transfer factor
Factors affecting TLCO (5)
- Ventilation Perfusion Mismatch - common in many lung diseases
- Reduction in the area of alveolar-capillary membrane - e.g. emphysema
- Increased thickness of alveolar-capillary membrane - e.g. pulmonary fibrosis
- Pulmonary Blood flow - e.g. pulmonary hypertension
- Haemoglobin concentration - e.g. anaemia leads to a decrease in TLCO
KCO
Transfer coefficient=functionality ‘per unit volume’ of lung.
Can increase to compensate for low TLCO if extra pulmonary causes of reduced lung volume obesity, thoracic cage abnormalities etc.
HRCT
1mm slice every 10 mm, good for suspected diffuse lung conditions
Spiral or Helical CT
Less resolution but done in continuum therefore dont miss small nodules etc
Pneumoconiosis
Lung disease caused by mineral dust
Fibrogenic=coal, silica, asbestos
Non fibrogenic= Siderosis (Iron) Welders
Baritosis (Ba miners)
Silicosis
- Early : diffuse nodules on CXR
Differentiate from sarcoidosis, TB, diffuse malignancy - Late : solid mass / upper zone
Differentiate from lung cancer, TB - Restrictive lung function abnormality
4.Characteristic findings on biopsy
Dense fibrosis with birefringent particles
Coal workers pneumoconiosis
Early : diffuse nodules on CXR
Differentiate from sarcoidosis, TB, diffuse malignancy
Late : solid mass / upper zone
Differentiate from lung cancer, TB
Restrictive lung function abnormality
Characteristic findings on biopsy
Dust accumulation around terminal bronchioles with fibrosis
Asbestos related disease
Heavy exposure= Lung cancer, asbestosis
Light exposure= mesothelioma, plueral plaques (no impact on lung function), plueral fibrosis
Transudate
Effusion fluid caused by changes in mechanical or oncotic pressure.
LOW protein <30g/L, LDH <200
Cardiac, renal failure, cirrhosis, ascites
Exudate
Effusion fluid caused by Increased permeabiliity of cap by pleural disease
Protein>30g/L, LDH>200
Malignancy, infection, inflammation,
Occupational asthma
Asthma which is caused by exposures to some agent at work (or is substantially worsened)
50% still have astham even after leaving work
Can be sensitiser (90%) Latency period between 1st exposure to a “sensitiser” and immunologically-driven symptoms
or irritant induced
Work related asthma
Asthma symptoms which are increased because of exposures at work (eg exercise, dust, cold)
Investigation of occupation asthma
History Skin prick tests Peak flow readings at work and home Airway responsiveness measurements Inhalational challenge test
Tx- as per standard BTS
Chronic Bronchitis
Chronic or recurrent excessive mucus secretion in the bronchial tree
Emphysema
An increase beyond the normal in the size of the air spaces distal to the terminal bronchiole(alveoli) accompanied by destruction of their walls and without obvious fibrosis.”
Cor Pulmonale
V/Q matching process constricts blood flow around areas of hypoxia, in emphysema hypoxia is everywhere=> pulomnary hypertension,
Type 1 Respiratory Failure
PaO2 < 8kPa
Causes
V/Q mismatch & shunt
Type 2 Respiratory Failure
PaO2 < 8 kPa on air & PaCo2 > 6 kPa
Causes
Hypoventilation
Increase in deadspace ventilation
V/Q mismatch
Symptoms suggestive of respiratory insufficiency
Breathless on exertion (dyspnoea) Breathless when lying down (orthopnoea) Poor concentration Extreme fatigue Decreased appetite Anxiety Nocturnal hypoventilation symptoms Disturbed sleep, frequent awakenings, morning headaches
Investigation of respiratory insufficiency
- FVC / SNIP / MIP / MEP - to measure and assess inspiratory and expiratory function
- Overnight oximetry or transcutaneous CO2 monitoring – to assess presence of nocturnal hypoventilation
- Arterial Blood Gas analysis – to determine urgency of treatment assessment
- Venous bicarbonate – to measure total CO2
- Sleep studies
Hypoventilation
COPD
OSA
DMD
OSA
Ix
Epworth sleepiness score
Limited somnography
Oximetry only
Tx
Weight loss
CPAP- effective at controlling Sx
DMD & COPD
NIV
Interstitial Lung disease
An imprecise term for a range of diseases which affect the lung parenchyma with cellular infiltration of the alveoli, interstitium and distal airways, and which may progress to fibrosis
Types of ILD
- Idiopathic Pulmonary Fibrosis
- Sarcoidosis
- Hypersensitivity Pneumonitis (EAA)
- Pneumoconiosis
- Connective tissue disease
- Drug related interstitial disease
IPF Tx
- Nothing
- Best Supportive Care ie:oxygen/rehab
- Pirfenidone/Nintedanib (expensive & rare)
- Recruit to Clinical Trials
- Transplant
IPF features Hx
- Progressive breathlessness
- Dry cough
- Failure to respond to treatments for other conditions
IPF Ex findings
- cyanosis
- clubbing
- fine crackles
- reduced chest expansion
Multisystem granulomatous disease of unknown cause primarily affecting the lung
Sarcoid
No Tx or steroids if required
ILD Ix
CXR=> HRCT
Lung Function
ABG
Auto antibodies and serum ACE
Bilateral Hilar/Mediastinal Lymphadenopathy
Sarcoid
TB
Lymphoma
Carcinoma
EBUS
Used to take biopsy mediastinal lymph nodes
EAA (hypersensitivity Pneumonisitis
Presents with cough, breathlessness and sometimes systemic symptoms of fever, weight loss
Occupation/Hobbies!
EAA Ex
Crackles & Also wheeze and squeaks
EAA Diagnosis
Usually suffice to have appropriate exposure, positive antibody response and clinical/radiological picture
EAA Ix
Mosaicism on HRCT (air trapping) hallmark
EAA Tx
Avoid antigen
Steroids
IPF
All lung function parameters reduced
Type 1 Respiratory Failure picture
