Pulmonary embolism rule-out criteria (PERC)
'’If your suspicion of PE is greater than this then you should move straight to the 2-level PE Wells score, without doing a PERC’’.
Clinical probability simplified scores
1. PE likely - more than 4 points
2. PE unlikely - 4 points or less
If a PE is ‘likely’ (more than 4 points)
1. Arrange an immediate (CTPA).
2. If there is a delay in getting the CTPA - interim therapeutic anticoagulation should be given until the scan is performed (DOAC).
If a PE is ‘unlikely’ (4 points or less)
1. Arrange a D-dimer test
WELL’S SCORE PE
Indications for thoracotomy in haemothorax
> 1.5L blood initially or losses of >200ml per hour for >2 hours
Lambert-Eaton myasthenic syndrome (LEMS)
proximal muscle weakness that improves with repeated effort (post-tetanic potentiation), and diminished reflexes that may return with repeated testing. The key diagnostic clue is the improvement in strength after initial exertion, which distinguishes LEMS from myasthenia gravis where weakness worsens with repeated use. LEMS is caused by antibodies against pre-synaptic voltage-gated calcium channels at the neuromuscular junction. Approximately 50-60% of LEMS cases are paraneoplastic, most commonly associated with small cell lung cancer. Testing for these antibodies is the most specific investigation and should prompt screening for underlying malignancy, particularly chest imaging. Given this patient’s age and smoking demographics (implied by the clinical context), identifying LEMS could lead to early detection of small cell lung cancer.
Alpha-1 antitrypsin deficiency
Surgery
Lung Volume reduction - as lack of elasticity - alveoli expand and trap air - reduced expansion during breathing.
The most common causes of bilateral hilar lymphadenopathy
sarcoidosis and tuberculosis
Worsening chest post high- pressure ventilation
Pneumothorax
TLCO and KCO
TLCO (DLCO)
= Transfer factor of the lung for carbon monoxide
= How well gas moves from alveoli → blood
KCO = TLCO corrected per unit of lung volume
- If TLCO ↓ BUT KCO ↑ → small lungs but efficient gas transfer
Fibrosis with lung shrinkage (early ILD)
Pneumonectomy or lobectomy
Kyphoscoliosis
Neuromuscular weakness
- B. If TLCO ↓ AND KCO ↓ → poor gas-transfer efficiency
Emphysema (destroyed alveoli)
Pulmonary vascular disease
Pulmonary hypertension
Anaemia
- C. If TLCO normal or ↑ AND KCO ↑ → increased pulmonary blood volume
Asthma
Pulmonary haemorrhage
Polycythaemia
Left-to-right shunts
Obesity
Asthma first presentation
According to the 2024 NICE/BTS/SIGN joint guidelines, when an adult presents with highly symptomatic asthma (such as regular nocturnal waking) or with a severe exacerbation, clinicians should treat the acute symptoms and start low-dose MART (maintenance and reliever therapy) immediately, bypassing Step 1.
long term control of symptoms in a patient with bilateral bronchiectasis
postural drainage. Postural drainage is a technique that uses gravity to help clear mucus from the lungs by positioning the patient so that the affected lung segments are above the trachea. This facilitates mucus clearance and helps reduce the frequency of infections, ultimately improving the patient’s quality of life.
Lung cancer: paraneoplastic features
Small cell
ADH
ACTH - not typical, hypertension, hyperglycaemia, hypokalaemia, alkalosis and muscle weakness are more common than buffalo hump etc
Lambert-Eaton syndrome
Squamous cell
parathyroid hormone-related protein (PTH-rp) secretion causing hypercalcaemia
clubbing
hypertrophic pulmonary osteoarthropathy (HPOA)
hyperthyroidism due to ectopic TSH
Adenocarcinoma
gynaecomastia
hypertrophic pulmonary osteoarthropathy (HPOA)
Leptospirosis
Bacterial disease caused by Leptospira species typically presents with fever, headache, chills, muscle aches and vomiting. It can also cause jaundice due to liver involvement. It is associated with exposure to contaminated water or soil - while the patient’s job as a sewage worker might suggest possible exposure, his symptoms are not suggestive of leptospirosis.
Lung abscess
Lung abscesses are usually secondary to aspiration pneumonia and present with more acute symptoms including fever and productive cough often with foul-smelling sputum.
COPD - reason for using inhaled corticosteroids
reduced exacerbations
Spontaneous Pneumothorax Mx
Silicosis
Silicosis is a fibrosing lung disease caused by the inhalation of fine particles of crystalline silicon dioxide (silica). It is a risk factor for developing tuberculosis (silica is toxic to macrophages).
Occupations at risk of silicosis
mining
slate works
foundries
potteries
Features
upper zone fibrosing lung disease
‘egg-shell’ calcification of the hilar lymph nodes
Aspergilloma
fungal growth affecting immunocompromised patients or those with underlying cavitating lung disease such as tuberculosis or emphysema. Symptoms of include fever, cough and haemoptysis. Treatment is with anti fungal medications such as itraconazole.
Panic attacks result
hyperventilation which causes a respiratory alkalosis. pO2 will be normal as there is no problems with gas exchange. There would be no metabolic compensation as the panic attack resolves rapidly.
The commonest causes of an anterior mediastinum mass
4 T’s: teratoma, terrible lymphadenopathy, thymic mass and thyroid mass
Klebsiella
Klebsiella pneumoniae is a Gram-negative rod that is part of the normal gut flora. It can cause a number of infections in humans including pneumonia (typically following aspiration) and urinary tract infections.
Features of Klebsiella pneumonia
more common in alcoholic and diabetics
may occur following aspiration
‘red-currant jelly’ sputum
often affects upper lobes
Prognosis
commonly causes lung abscess formation and empyema
mortality is 30-50%
idiopathic pulmonary fibrosis
Pirfenidone and nintedanib can be used as drug management options
Haemoptysis in mitral stenosis
thought to occur secondary to rupture of the bronchial veins caused by raised left atrial pressure.
granulomatosis with polyangiitis.
The combination of pulmonary haemorrhage (haemoptysis), renal impairment (rapidly progressive glomerulonephritis) and flat or saddle nose (due to a collapse of the nasal septum)
main indications for placing a chest tube in pleural infection:
Patients with frankly purulent or turbid/cloudy pleural fluid on sampling should receive prompt pleural space chest tube drainage.
The presence of organisms identified by Gram stain and/or culture from a non-purulent pleural fluid sample indicates that pleural infection is established and should lead to prompt chest tube drainage.
Pleural fluid pH < 7.2 in patients with suspected pleural infection indicates a need for chest tube drainage.
