Related Subjects: Asthma
|Acute Severe Asthma
|Exacerbation of COPD
|Pulmonary Embolism
|Cardiogenic Pulmonary Oedema
|Pneumothorax
|Tension Pneumothorax
|Fat embolism
|Hyperventilation Syndrome
|Acute Respiratory Distress Syndrome (ARDS)
|Respiratory Failure
Patterns of lung disease
- Understanding the patterns will make everything much easier. Not all patients and their diseases fit nicely into discrete categories but the differentiation into restrictive and obstructive is useful and is applicable to many respiratory illnesses
- Pulmonary function testing caveats
- These measurements are dependent on the patient giving their best effort and the less the patient tries the worse the values
- This can lead to misdiagnosis and over treatment in the less compliant patients.
- Diffusion Capacity Test (DLCO): Measures how well the lungs transfer oxygen to the blood, used in interstitial lung diseases.
Imaging Studies
- Chest X-ray: Used to detect abnormalities in the lungs, such as infections, tumours, or chronic lung diseases.
- CT Scan: Provides detailed images of the lungs and can detect smaller lesions that might not appear on a chest X-ray.
- MRI: Useful in identifying soft tissue abnormalities and in some cases, tumours.
- Ultrasound: Typically used for pleural effusions or to guide thoracentesis.
Pulmonary Function Tests (PFTs)
- Spirometry: Measures the amount and speed of air a person can inhale and exhale, useful for diagnosing asthma, COPD, and other conditions. FEV: amount of air expelled in the first second from a forced expiration at maximal inspiration. FVC : amount of air that can be expelled in a single breath. Residual volume : the volume of air remains in the lungs after full expiration. Can only be measured indirectly using total body plethysmography or helium dilution.
- Peak Flow Meter: A simple test that measures the peak expiratory flow rate, often used in asthma management. The maximum rate at which air can be expelled from the lungs and used as a simple guide often in asthma to airways obstruction
- Body Plethysmography: Determines the total lung capacity and can help in diagnosing restrictive lung diseases.
Laboratory Tests
- Arterial Blood Gas (ABG) Analysis: Measures the levels of oxygen and carbon dioxide in the blood to assess respiratory function.
- Sputum Analysis: Examines mucus (sputum) coughed up from the lungs to detect infections, cancers, or inflammatory conditions.
- Complete Blood Count (CBC): Can identify infections, anaemia, and other conditions that might affect lung function.
- Allergy Testing: Identifies specific allergens that may trigger respiratory symptoms.
Endoscopic Procedures
- Bronchoscopy: Involves inserting a flexible tube through the nose or mouth into the airways to view the lungs and collect samples.
- Thoracoscopy: A minimally invasive procedure to examine the pleural space and take biopsies if needed.
- Mediastinoscopy: Used to examine and biopsy the lymph nodes in the mediastinum (the area between the lungs).
Biopsy Procedures
- Lung Biopsy: Involves taking a small sample of lung tissue to diagnose conditions such as cancer, infections, or inflammatory diseases.
- Pleural Biopsy: Involves sampling tissue from the pleura (the lining around the lungs) to diagnose pleural diseases.
- Needle Aspiration: Used to collect samples from lung masses, pleural effusions, or lymph nodes under imaging guidance.
Nuclear Medicine Studies
- V/Q Scan (Ventilation/Perfusion Scan): Assesses airflow (ventilation) and blood flow (perfusion) in the lungs, often used to diagnose pulmonary embolism.
- Positron Emission Tomography (PET) Scan: Used to detect cancer, infections, or inflammation in the lungs.
Cardiopulmonary Exercise Testing (CPET)
- CPET: Evaluates the respiratory, cardiovascular, and muscular systems during exercise to identify causes of exercise intolerance or unexplained dyspnoea.