Respiratory Flashcards
How to confirm diagnosis of lung cancer? What is the most common type of primary lung cancer?
Collect a sample for biopsy through either bronchoscopy (if central tumour) or thoracoscopy (if pleural effusion).
Approximately 95% of all primary lung tumours are bronchial carcinomas, and they can be classified as small-cell lung cancer, or non-small-cell lung cancer.
Adenocarcinoma accounts for 39% of NSCLCS and it’s the most common bronchial carcinoma associated with asbestos, and it’s more common in non-smokers, compared to other cell types.
Which organism should be suspected as etiology for respiratory symptoms of dry cough, shortness of breath, hyponatraemia and lymphocytopenia for a patient that recently stayed at a hotel? How to treat it?
Suggestive of legionella infection.
Macrolides, fluoroquinolones, or tetracyclines can be used.
If a macrolide is used, clarithromycin or azithromycin are usually the choices.
L. pneumophila is found in natural water supplies and soil, and it’s transmitted by droplet inhalation of contaminated water.
Clinchers - traveling, hotel stays, whirlpool spas, hot tubs
How to diagnose and treat bronchiectasis?
Diagnosis
- CT chest confirms it
- baseline chest X-ray should be done in all patients: may be normal, or show peribronchial thickening, crowding of the bronchi (tramlines) or ring opacities
Treatment: to prevent further deterioration
- bronchodilators
- chest physical therapy and postural drainage of bronchial secretions
- stop smoking
- immunisation against influenza and pneumococcus
- long-term oral antibiotics for patients having 3 or more exacerbations per year requiring antibiotic therapy or patients with fever exacerbations that are causing significant morbidity
What clinchers related to mesothelioma? How should it be treated?
- associated with occupational exposure to asbestos
- report deaths to the coroner as it’s an industrial disease
- latent period may be up to 45 years
- compensation is often available for patients and families
- often the diagnosis is made post-mortem
Management is usually symptomatic since the cure is only possible for localised stage I mesothelioma
How to recognise obstructive lung disease in the pulmonary function test? What are examples of obstructive diseases?
Observe forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC)
Obstructive lung disease
- FEV1 less than 80% predicted (low)
- FVC more than 80% predicted (normal)
- FEV1/FVC less than 0.7 (low)
Examples: asthma, COPD, cystic fibrosis, bronchiectasis
They cause airway resistance to expiratory flow and so result in obstructed airways. When expiratory flow is obstructed, the patient will struggle to breathe air out and thus FEV1 will decrease. Because FEV1 is the numerator of the ratio, any obstructive disease will also cause a decrease in the ratio.
How to recognise restrictive lung disease in the pulmonary function test? What are examples of restrictive diseases?
Observe forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC)
Restrictive lung disease
- FEV1 less than 80% predicted (low)
- FVC less than 80% predicted (low)
- FEV1/FVC 0.7 or more (normal or high)
Examples: pulmonary fibrosis, interstitial lung disease (obesity, chest or spine deformities, neuromuscular disorders)
Restrictive lung diseases restrict lung expansion and cause a decrease in the amount of air that the lung can hold, leading to decrease in the vital capacity, which results in a decreased FVC. Because there’s also lung elasticity, it also becomes harder for the lungs to force out air, and this causes decrease in the FEV1. Because both FEV1 and FVC decrease, the ratio remains the same.
What are the clinchers related to staphylococcal pneumonia?
- caused by staphylococcus aureus
- multiple-lobe involvement and cavitation
- co-infection with influenza
What is the CURB-65 score?
C - confusion
U - urea > 7 mmol/L
R - respiratory rate above 30 ipm
B - systolic blood pressure below 90 or diastolic equal or below 60
65 - above 65 yo
Is pneumococcus a gram positive or gram negative bacteria?
Pneumococcus is a gram positive cocci, and it’s the most common cause of community acquired pneumonia
When should atypical pneumonia be suspected?
- prolonged and gradual onset
- flu-like symptoms classically precede a dry cough
- bilateral consolidation on X-ray
- erythema multiforme (infection with mycoplasma pneumoniae)
What should be suspected in a tall thin young man who presents with sudden pain and breathlessness?
Pneumothorax
What are the clinchers for sarcoidosis?
- bilateral hilar lymphadenopathy
- skin rash
Lofgren syndrome - a distinct sarcoid syndrome
- erythema nodosum
- arthritis
- hilar adenopathy
In a case of spontaneous secondary pneumothorax with evidence of lung disease, which size of pleural effusion determines needle aspiration and placement of chest drain?
< 1 cm: conservative management (give supplementary oxygen)
1-2 cm: aspirate using 16-18 gauge cannula
> 2 cm or breathless: insert chest drain
Which organism most commonly causes pneumonia in a HIV patient that presents with desaturation on exercise?
Pneumocystis carinii infection (pneumocystis jiroveci pneumonia)
How to investigate and diagnose a Pancoast tumour?
Pancoast tumour is a tumour in the pulmonary apex, which presents as Horner’s syndrome (ptosis, anhidrosis, miosis) if there’s ipsilateral invasion of the cervical sympathetic plexus, and as wasting of the intrinsic hand muscles and paraesthesiae in the medical side of the arm (along with shoulder and arm pain) it there’s brachial plexus invasion.
Investigations
- MRI scan only assess structures at the thoracic inlet since it provides a higher soft tissue resolution
- histology is achieved by percutaneous methods rather than bronchoscopy since there tumours are peripherally located
