Respiratory Flashcards
Give some red flags for a respiratory history/examination
- Haemoptysis/brown sputum
- Weight loss
- Cough >3 weeks
- Chest pain
- Drenching night sweats
- Foreign travel
- Smoking history
- Sudden onset SOB
- Risk factors for PE
What is the most common lung disease in the UK?
Asthma
Give the 3 mechanisms behind airway narrowing in asthma
- Bronchial muscle contraction
- Inflammation caused by mast cell degranulation
- Increased mucus production
Asthma often shows a diurnal variation. What does that mean?
symptoms often worse in morning
Describe the percussion in asthma
Hyperresonance (due to presence of air)
Describe the inflation of the lungs in acute asthma
Hyperinflation
Describe the auscultation of the lungs in asthma
Bilateral decreased air entry
Wheeze
Are the symptoms/signs in asthma bilateral or unilateral?
Bilateral
What is a ‘silent chest’ in asthma a sign of?
Severe illness - life-threatening
What is the diagnostic investigation in asthma?
Spirometry
How does spirometry and PEFR differ?
Both tests measure the speed and efficiency with which air moves in and out of the lungs.
Spirometry - offers a larger set of parametric values regarding lung health than a peak flow meter does and requires a patient to perform specific breathing manoeuvres using a spirometer.
PEFR - can be performed at bedside/patient home
What spirometry result indicates asthma?
FEV1/FVC <0.7 (70%) indicates obstructive airway disease
What is the FEV1/FVC ratio?
The FEV1/FVC ratio is the ratio of the forced expiratory volume in the first one second to the forced vital capacity of the lungs (i.e. indicates how much air you can forcefully exhale)
Measured by spirometry
Give some other investigations that can be used in chronic asthma?
- Fractional exhaled nitric oxide (FeNO)
- Bronchodilator reversibility tests
- Skin prick test - confirm atopy
What bronchodilator reversibility test result indicates asthma?
Improvement of FEV1 >12% after bronchodilator therapy is diagnostic
What is the stepwise pharmacological long-term management of asthma
- Short-acting b2 agonist (SABA) e.g. salbutamol
- Add inhaled low dose inhaled corticosteroid (ICS) e.g. beclomethasone
- Add long-acting b2 agonist e.g. salmeterol
- Two options:
- Increase ICS dose
- Add leukotriene receptor antagonist e.g. montelukast
What are the aims of pharmacological management of asthma?
- No daytime symptoms
- No night-time waking due to asthma
- No asthma attacks
- No limitations on activity including exercise
- Minimal side effects from medication
Pathophysiology behind an asthma attack?
IgE type 1 hypersensitivity reaction leading to smooth muscle contraction, bronchial oedema and mucus plugging.
What medications can exacerbate asthma?
- Beta blockers e.g. bisoprolol → contraindication
- NSAIDs (some but not all) → caution
- AChEIs –> due to increased bronchial secretions
Give some triggers for an asthma attack
- Exposure to allergens e.g. dust, pollution, animal hair or smoke
- URT or LRTIs
- Cessation or reduction of asthma medications
- Concomitant medications e.g. beta blockers, NSAIDs
- Triggers e.g. exercise, cold air
Give some signs of an acute asthma attack
- Use of accessory muscles of respiration
- Hyperinflation of the chest
- Tachypnoea
- Tachycardia
- Diaphoresis (sweating)
Give some signs of a severe asthma attack
- Inability to speak in full sentences
- RR >25
- Peak flow 33-50% predicted
Give some signs of a life-threatening asthma attack
- PEFR <33% predicted
- O2 sats <92%
- Silent chest on auscultation
- Confusion
- Bradycardia
- Hypotension
- Cyanosis
- Exhaustion – weak or no respiratory effort
What may bradycardia in a life-threatening asthma attack indicate?
Impending respiratory arrest
What does an FeNO test indicate?
Measures level of NO in breath which is a sign of inflammation in your lungs
Which bloods are important in acute asthma?
- FBC – infection
- CRP – infection
- Eosinophil count
- Total IgE
- IgE to aspergillus
Which imaging is 1st line in acute asthma?
CXR - but doesn’t delay management
What may a CXR in acute asthma show?
usually normal (may show hyperinflation or bronchial wall thickening)
Give the stepwise pharkmacological management in an acute asthma attack (ABCDE)
- Oxygen
- Nebulised salbutamol (high dose)
- Nebulised ipratropium bromide if needed
- Steroid therapy - oral prednisolone or IV hydrocortisone
- IV Magnesium sulphate
- IV aminophylline
When would ipratropium bromide be given in acute asthma? What is the effect of this?
Add for patients with acute severe or life-threatening asthma or to those with a poor initial response to b2 agonist therapy.
Combining nebulised ipratropium bromide with a nebulised b-2 agonist produces significant bronchodilation than a b-2 agonist alone.
Who should steroid therapy be administered to in patients presenting with an acute asthma attack?
ALL patients with acute asthma
What steroids should be used in acute asthma?
Oral prednisolone 40-50mg
If oral route unavailable (likely) → IV hydrocortisone
How long should oral prednisolone be continued for following an acute asthma attack?
5 days or until full recovery
When would you consider giving IV magnesium sulphate in acute asthma?
- Acute severe asthma who have not had a good response to inhaled therapy
- Life-threatening or near-fatal asthma
- Only use after consultation with senior medical staff
What would reduced air entry in acute asthma indicate?
significant airway compromise
What would absent air entry on auscultation in acute asthma indicate?
Underlying pneumothorax
What would dullness on percussion in acute asthma indicate?
Pleural effusion
Lobar collapse
Typical ABG results in acute asthma?
Low PaO2, low PaCO2
If PaCO2 normal or raised → major concern
What is COPD?
A triad of chronic bronchitis, emphysema and small airway fibrosis causing irreversible obstruction of air flow; bronchitis or emphysema can be the predominant condition.
Most common cause of COPD?
Smoking (95%)
Other causes of COPD?
- Dust, silica, pollutants
- Alpha 1 antitrypsin deficiency (a-1 is a protease inhibitor)
- Autosomal dominant
- Raises risk for lung and liver disease
COPD is usually a combination of chronic bronchitis and emphysema. What are these 2 conditions?
‘Chronic bronchitis’ - chronic inflammation of the bronchi (usually defined as a productive cough on most days for 3 months a year over 2 successive years)
‘Emphysema’ - enlargement of air spaces in the terminal bronchioles leading to inefficient gas exchange ratios and poor air outflow
What is the pathogenesis behind COPD?
Chemicals and heat trigger inflammation in bronchi and lung parenchyma
- Bronchi → persistent inflammation leads to scarring and mucus hyperplasia (bronchitis)
- Parenchyma → inflammation leads to alveolar wall loss (emphysema)
Give some triggers for COPD exacerbations
- Viral or bacterial lung infection (acute bronchitis or pneumonia)
- Smoking
- Exposed to smoke or air pollution
Give some symptoms of COPD
- Dyspnoea (may only happen at first when exercising)
- Chronic productive cough (sputum usually colourless, may become green in LRTIs)
- Recurrent LRTIs
- Fatigue
- Headache (due to CO2 retention)
- Trouble taking a deep breath
- Chest tightness
Give some symptoms of an exacerbation of COPD
- More coughing, wheezing, or SOB than usual
- Changes in colour, thickness or amount of mucus
- Feeling tired for more than 1 day
- Swelling of legs or ankles
- O2 levels lower than normal
- Severe → cyanosis, severe SOB, chest pain, confusion
What signs are seen in a COPD exacerbation?
- Accessory muscle use & pursed lips
- Tachypnoea
- Hyperinflation
- Reduction of cricosternal distance
- Reduced chest expansion
- Hyper resonant percussion
- Decreased/quiet breath sounds
- Wheeze on auscultation (due to inflammatory airway oedema and mucous obstruction)
- Cyanosis
- Cor pulmonale (signs of RHF)
- CO2 retention flap
- Reduced conscious level
- Severe → tachycardia, tachypnoea, hypoxia, cyanosis, reduced consciousness
What is the typical spirometry finding in COPD?
FEV1/FVC <0.7
What SpO2 should you aim for in COPD patients?
88-92%
How can COPD affect the heart?
COPD can cause low oxygen levels in the blood, thereby placing additional stress on the heart.
This can lead to right ventricle hypertrophy and potentially cor pulmonale
What is cor pulmonale?
Cor pulmonale is a condition that causes the right side of the heart to fail.
Long-term high blood pressure in the arteries of the lung and right ventricle of the heart can lead to cor pulmonale
What may an FBC show in COPD?
Raised MCV - polycythaemia
What may an ABG show in COPD?
Low PaO2
Raised PaCO2 (type 2 respiratory failure)
What is the purpose of a sputum sample in COPD exacerbation?
Enables targeted antibiotic therapy
What may a CXR show in COPD
- Hyperinflated chest (>6 anterior ribs)
- Bullae
- Decreased peripheral vascular markings
- Flattened hemidiaphragms
How should oxygen be delivered to COPD patients during acute exacerbations?
Use a venturi mask and titrate oxygen appropriately.
If the patient is conscious, sit them upright as this can also help with oxygenation.
Give the pharmacological management of an acute COPD exacerbation
- Oxygen
- Nenuclised salbutamol
- Nebulised ipratropium bromide
- Steroids
What steroids should be used in the management of a COPD exacerbation?
Oral prednisolone (IV hydrocortisone if needed)
Give the stepwise pharmacological management of chronic COPD
Step 1 – Short acting B2-agonist (SABA) OR short acting muscarinic antagonist (SAMA)
Step 2 – Add LABA AND LAMA
Step 3 – LAMA + LABA + ICS
What can lung cancers be divided into?
Small cell & non small cell tumours
Are small cell or non small cell lung cancers more common?
Non-small cell (80%)
What is the most common type of NSCLC?
Adenocarcinoma (40%)
What is the 2nd most common type of NSCLC?
Squamous cell carcinoma (20%)
Give some red flag symptoms for lung cancer
- Cough
- Haemoptysis
- Dyspnoea
- Chest pain
- Weight loss
- N&V
- Anorexia
Lung cancer can present with Horner’s syndrome. Give the location of the tumour in this instance
Apical → interrupted sympathetic supply to face
Lung cancer can lead to many complications.
What chest signs could be seen during an examination?
- Consolidation – pneumonia
- Collapse – absent breath sounds, ipsilateral tracheal deviation
- Pleural effusion – stony dull percussion, decreased vocal resonance and breath sounds
Are SCLCs or NSCLCs more likely to cause paraneoplastic syndromes?
SCLCs
Give some paraneoplastic syndromes that can be caused by lung cancer
- Cushing’s syndrome → ectopic ACTH secretion
- SIADH → ectopic SIADH syndrome
- Lambert-Eaton syndrome
- Hyperparathyroidism
How does parathyroid hormone affect calcium?
parathyroid hormone stimulates the release of calcium from large calcium stores in the bones into the bloodstream (hyperparathyroidism → hypercalcaemia)
Give the pathology behind lung cancer manifesting as SOB
If cancer invades major airways
Give the pathology behind lung cancer manifesting as haemoptysis
Invasion of cancer into airways (friable tissue) may lead to bleeding
Give the pathology behind lung cancer manifesting as pain
Local invasion affecting the lining of the pleural cavity or bone, causing pain
Give the pathology behind lung cancer manifesting as a pleural effusion
Can cause inflammatory reactions which can leads to the accumulation of fluid in the pleural space
Give the pathology behind lung cancer manifesting as a superior vena cava obstruction
Cancer may invade into surrounding lung tissues, leading to compression of the draining of the SVC leading to dyspnoea and facial plethora due to venous congestion
Give the pathology behind lung cancer manifesting as a pneumothorax
Invasion of the tumour may lead to a communication between the lung parenchyma and the pleural cavity, resulting in the collapse of the lung
Give the pathology behind lung cancer manifesting as atelectasis
Invasion may lead to total obstruction of the airway leading to collapse of that lobe
What is the 1st line investigation in suspected lung cancer?
CXR
Is pleural effusion typically unilateral or bilateral in lung cancer?
Unilateral
Give some potential CXR features in lung cancer
- Nodules
- Hilar enlargement
- Lung collapse
- Pleural effusion – usually unilateral in cancer
- Consolidation
- Peripheral opacity – a visible lesion in the lung field
- Bony metastases
What staging system is used to stage lung cancer?
TNM
What investigation can be used in the staging of lung cancer?
CT scan of chest, abdomen and pelvis
What is the most common type of lung cancer in the UK?
Adenocarcinoma
Which lung cancer is the least likely to be related to smoking?
Adenocarcinoma
What cells do adenocarcinomas arise from?
Arises from mucous cells in bronchial epithelium
Which type of lung cancer is most likely to cause a pleural effusion?
Adenocarcinoma (and mesotheliomas)
Which type of lung cancer is most commonly related to hypercalcaemia?
Squamous cell carcinoma
Lung cancer can cause hypercalaemia via which 2 mechanisms?
- bone destruction
- production of PTH analogues
What cells do small cell lung cancers arise from?
From endocrine cells (Kulchitsky cells) – these are APUD cells
Which 2 hormones with SCLCs most typically secrete? Why?
Due to high grade neuroendocrine nature → adrenocorticotropic hormone (ACTH) and anti-diuretic hormone (ADH)
SCLC is also associated with Addison’s disease. What is the pathophysiology behind this?
Tissue destruction of the adrenal glands → low cortisol (and aldosterone)
What is Lambert-Eaton syndrome?
The result of antibodies produced by the immune system against small cell lung cancer cells
Why are SCLCs responsible for multiple paraneoplastic syndromes?
SCLCs contain neurosecretory granules that can release neuroendocrine hormones
Pathophysiology behind Lambert-Eaton syndrome?
Antibodies target and damage voltage-gated calcium channels in motor neurons
Symptoms of Lambert-Eaton?
- Proximal weakness
- Intraocular muscle weakness – diplopia (double vision)
- Levator muscles in eyelid weakness – ptosis
- Pharyngeal muscle weakness – slurred speech, dysphagia
- Reduced tendon flexes
What cells does mesothelioma affect?
A lung malignancy affecting the mesothelial cells of the pleura.
What is mesothelioma strongly linked to?
Asbestos exposure
What is the latent period between asbestos exposure and development of mesothelioma?
Up to 45 years
What is a pneumothorax
Air within the pleural space.
What are the 2 major classifications of a pneumothorax?
Spontaneous & traumatic
Spontaneous pnuemothorax’s can be 1ary or 2ary. What is the difference?
1ary → No underlying lung pathology
2ary → Underlying lung pathology
What type of patient does a 1ary spontaneous pneumothorax present in?
Tall thin young men
Typical Presentation in Exams – Young, tall, thin man presenting with sudden breathlessness and pleuritic chest pain, possibly whilst playing sports.
Give some underlying pathologies that can lead to 2ary spontaneous pneumothorax’s
- Connective tissue disease e.g. Marfan’s syndrome, Ehlers-Danlos syndrome
- Obstructive lung disease e.g. asthma, COPD
- Infective lung disease e.g. TB, pneumonia
- Fibrotic lung disease e.g. cystic fibrosis, idiopathic pulmonary fibrosis
- Neoplastic disease e.g. bronchial carcinoma
Traumatic pneumothorax’s can be classified into iatrogenic and non-iatrogenic causes.
Give some examples for both
Iatrogenic → central line insertion, positive pressure ventilation, lung biopsy
Non-iatrogenic → penetrating trauma, blunt trauma with rib fracture
Give some symptoms of a pneumothorax
- Sudden onset SOB
- Pleuritic chest pain
How is each factor affected in a pneumothorax:
- Chest expansion
- Percussion
- Breath sounds
- Vocal resonance
- Chest expansion → reduced on affected side
- Percussion → hyper resonance on affected side
- Breath sounds → reduced/absent on affected side with no added sounds
- Vocal resonance → reduced on affected side
What is the 1st line investigation in a pneumothorax?
CXR
What type of cannula is used to aspirate a pneumothorax?
A 16-18G cannula under local anaesthetic
What is a tension pneumothorax?
Caused by trauma to the chest wall that creates a one-way valve that lets air in but not out of the pleural space.
Pathology behind a tension pneumothorax?
- One-way valve means that during inspiration, air is drawn into the pleural space and during expiration, the air is trapped in the pleural space.
- More air keeps getting drawn into the pleural space with each breath and cannot escape.
- This creates pressure inside the thorax that will push the mediastinum across, kink the big vessels in the mediastinum and cause cardiorespiratory arrest.
Signs of a tension pneumothorax?
- Tracheal deviation away from the side of the pneumothorax
- Reduced air entry to affected side
- Increased resonant to percussion on affected side
- Tachycardia
- Hypotension
Management of tension pneumothorax?
ABCDE approach
Immediate needle decompression using a 16-gauge cannula (large bore cannula) inserted at the second intercostal space in the mid-clavicular line on the affected side.
Chest drain insertion (then obtain CXR for positioning)
Where must the needle be inserted in a tension pneumothorax?
Needle must be inserted just above the 3rd rib to avoid damaging the neurovascular bundle
What is a pleural effusion?
The abnormal buildup of fluid in the pleural cavity.
What protein count defines an exudative fluid?
High (>35 g/L)
What protein count defines a transudative fluid?
Low (<25g/L)
What is the pathophysiology behind an exudative pleural effusion?
Increased pleural and capillary permeability due to inflammation, resulting in protein leaking out of tissues into pleural space
What are the most common causes of exudative pleural effusions?
- Infection – pneumonia, tuberculosis
- Malignancy – bronchial carcinoma, mesothelioma, lung metastases
What is the pathophysiology behind transudative pleural effusions?
Disruption in hydrostatic pressure → increase in pulmonary hydrostatic pressure forces fluid out of pulmonary capillaries into pleural space
Disruption in oncotic pressure → impaired reabsorption of fluid from pleural space into pulmonary capillaries
What are the 2 most common causes of transudative pleural effusions?
- Heart failure
- Liver failure (cirrhosis)
Would nephrotic syndrome cause a transudative or exudative pleural effusion?
Transudative
Would hypoalbuminaemia cause a transudative or exudative pleural effusion?
Transudative
Define an empyema
pus in pleural space
Disruption of which structure leads to a chylothorax?
Chyle in pleural space due to disruption of thoracic duct (neoplasm, trauma, infection/inflammation)
Are transudative or exudative pleural effusions more likely to be bilateral?
Transudative pleural effusions are more likely to be bilateral whilst exudative pleural effusions are more likely to be unilateral.
Symptoms of a pleural effusion?
- Dyspnoea (SOB)
- Reduced exercise tolerance
- Pleuritic chest pain
- Other areas to cover in history:
- Symptoms suggestive of lung cancer → haemoptysis, weight loss
- Symptoms suggestive of heart failure → orthopnoea, paroxysmal nocturnal dyspnoea, leg swelling
- Symptoms suggestive of lung infection → productive cough, fever
- Social history → smoking history (lung cancer risk), asbestos exposure (mesothelioma)
Chest signs possibly seen in pleural effusion:
- trachea
- chest expansion
- percussion
- auscultation
- vocal resonance/tactile vocal fremitus
- trachea → central/deviated away from affected side (if large)
- chest expansion → reduced on affected side
- percussion → stony dull on affected side
- auscultation: reduced/absent breath sounds over effusion & bronchial breathing at upper border of effusion
- vocal resonance/tactile vocal fremitus → reduced over effusion
Why would an ECG be indicated in a pleural effusion?
- Look for cardiac cause of chest pain and breathlessness
- Look for signs of right heart strain (PE)
Why would a urine dip be indicated in pleural effusion?
- assess for proteinuria which may indicate nephrotic syndrome
Potential blood tests in a pleural effusion:
- FBC → may show raised WCC (infection)
- U&Es → may show raised creatinine (renal impairment)
- LFTs & coagulation profile → may show low albumin and raised ALT/AST (cirrhosis)
- CRP → infection
- Blood cultures → infection
- ABG → if oxygenation affected
- D-dimer → if PE suspected
- Amylase → if pancreatitis suspected
- TFTs → if hyperthyroidism suspected
1st line imaging in pleural effusion?
CXR
Give some potential CXR findings in a pleural effusion
- Unilateral → typically exudative
- Bilateral → typically transudative
- Blunting of costophrenic angles (>200ml fluid needed to be visible on PA film)
- Fluid in lung fissures
- Meniscus (curving upwards where effusion meets chest wall and mediastinum) if large
- White out of one hemifield if large
- Tracheal and mediastinal deviation if massive
Thoracentesis is indicated in all patients except who?
Required in all patients except those with clear evidence of HF (raised JVP, pitting ankle oedema, signs on CXR)
What would purulent pleural fluid upon aspiration indicate?
infection
What would bloody fluid upon aspiration indicate?
malignancy, PE or trauma
Pleural effusion CXR findings:
Management of large pleural effusions?
- ABCDE approach if required
- Pharmacological:
- Diuretics in HF
- Antibiotics in infection
- Larger effusions:
- Pleural aspiration with needle (temporary symptomatic relief but may recur)
- Drainage via chest drain (can prevent it recurring)
Give some complications of a pleural effusion
- Empyema → infected pleural effusion
- Lung damage
- Pneumothorax
- Pleural thickening
Pathophysiology of pneumonia?
- Inflammation leads to fluid and blood cells leaking into the alveoli.
- The infection spreads across the alveoli and eventually the lung tissue becomes consolidated, impairing the gas exchange due to reduced ventilation.
What are the 3 most common causative organism in community acquired pneumonia (CAP)?
- Streptococcus pneumoniae → most common
- Haemophilus influenzae
- Mycoplasma pneumoniae
Give some symptoms of a pneumonia
- Fever
- Malaise
- Rigors
- Cough
- Purulent sputum
- Pleuritic chest pain
- Haemoptysis
Chest examination findings in pneumonia?
- Percussion → dull (due to lung tissue collapse and/or consolidation)
- Vocal resonance/tactile fremitus → increased
- Bronchial breath sounds
- Focal coarse crackles
- Pleural rub
What are bronchial breath sounds?
- Harsh sounds equally loud on inspiration & expiration are equal
- Audible pause between inspiration & expiration
What are focal coarse crackles in pneumonia?
these are air passing through sputum in airways
what is a pleural rub? cause?
An audible sound heard in patients with pleurisy
Caused by layers of pleura rubbing against each other
Why is a urine sample for antigen testing required in pneumonia?
To distinguish between legionella and pneumococcal urinary antigens
After how many days of starting Abx should inflammatory markers be repeated in pneumonia?
3 days
Typical Abx management of moderate-severe CAP?
IV antibiotics 7-10 day course of dual Abx (amoxicillin + macrolide e.g. co-amoxiclav + clarithromycin)
Typical Abx management of mild CAP?
5-day course of oral Abx (amoxicillin or macrolide)
Define hospital acquired pneumonia
A LRTI that develops >48 hours after hospital admission
Top 3 causative organisms of hospital acquired pneumonia?
- Pseudomonas aeruginosa
- Staph. aureus
- Enterobacteria
Who does aspiration pneumonia occur in?
Occurs in patients with an unsafe swallow
Risk factors for aspiration pneumonia?
- Myasthenia gravis
- Bulbar palsy
- Alcoholism
- Achalasia
Which lung is more affected in aspiration pneumonia? Why?
R lung more affected due to R bronchus being more vertical and wider
What are the criteria of the CURB 65 score?
- C – Confusion (AMTS = 8)
- U – Urea >7mmol/l
- R – Respiratory rate >/= 30
- B – Blood pressure <90 systolic and/or <60mmHg diastolic
- 65 – Age >/= 65 y/o
Define atypical pneumonia
Pneumonia caused by an organism that cannot be cultured in the normal way or detected using a gram stain
How does the antibiotic management for atypical pneumonia change?
Do not respond to penicillins
Treated with:
- Macrolides e.g. clarithromycin
- Fluroquinolones e.g. levofloxacin
- Tetracyclines e.g. doxycycline
What are the 3 most common causative organisms of atypical pneumonia?
- Legionella pneumophila (Legionnaire’s disease)
- Mycoplasma pneumoniae
- Chlamydophila pneumoniae
Cause of Legionella pneumonia?
Infected water supplies or air conditioning units
Typical patient → Cheap hotel holiday and presents with hyponatraemia
What electrolyte disturbance does Legionella pneumonia present with?
Hyponatraemia by causing an SIADH (excess secretion of ADH causes excess absorption of water → dilution of sodium)
how does mycoplasma pneumonia typically present?
- Milder pneumonia
- Rash → erythema multiforme characterised by varying sized ‘target lesions’ formed by pink rings with pale centres
- Can cause neurological symptoms in young patients
What rash is characteristic of mycoplasma pneumoniae?
erythema multiforme → characterised by varying sized ‘target lesions’ formed by pink rings with pale centres
What patient is chlamydophila pnuemoniae typically seen in?
School aged child with mild to moderate chronic pneumonia and wheeze
Why can COPD lead to 2ary polycythaemia?
COPD (and sleep apnoea) can cause an increase in erythropoietin, due to not enough oxygen reaching the body’s tissues.
Give 3 endocrine manifestations of paraneoplastic syndromes in lung cancer
- Hypercalcaemia
- SIADH
- Ectopic Cushing’s syndrome
What 4 cancers are most commonly associated with hypercalcaemia?
- Lung
- Breast
- Renal
- Myeloma
What type of lung cancer is most commonly associated with hypercalcaemia?
Squamous cell carcinoma
Describe symptoms seen in hypercalaemia of malignancy
Stones → renal stones, flank pain, frequent urination
Bones → bone pain
Moans → confusion, depression, dementia, memory loss
Groans → N&V, diarrhoea, abdominal pain
Cause of symptoms seen in ectopic Cushing’s syndrome?
caused by production of ACTH by non-pituitary tissue leading to hypercortisolism.
Signs & symptoms typical of Cushing’s syndrome?
- Truncal obesity
- Facial plethora
- Pathologic striae
- Dorsocervical fat pad enlargement
- Proximal muscle weakness
- Hyperpigmentation
- Psychosis, and confusion
Note - ECS caused by small cell lung cancer (SCLC), or other aggressive tumours, may have an atypical presentation with muscle wasting and weight loss instead of classical sings of hypercortisolism such as moon facies and weight gain.
What electrolyte abnormalities are seen in Ectopic Cushing’s syndrome? (Na, K+)
Hypokalaemia & hypernatraemia
What type of lung cancer is ectopic Cushing’s syndrome typically associated with?
Small cell lung cancer
What is the most common neurological manifestation of small cell lung cancer
Lambert-Eaton myasthenic syndrome (LEMS)
What is LEMS?
LEMS is a rare autoimmune disorder of the neuromuscular junction and may precede the diagnosis of lung cancer.
What is typically the initial symptom of LEMS?
Progressive proximal, lower greater than upper extremity weakness is nearly always the initial symptom.
LEMS vs myasthenia gravis?
Myasthenia gravis → the acetylcholine receptor on the nerve is affected,
LEMS → the voltage gated calcium channel on the nerve is affected
Why is thoracentesis not indicated in a pleural effusion in heart failure patients?
Patients who present with clearcut evidence of conditions known to cause pleural effusions, such as congestive heart failure, do not require thoracentesis.
What type of pneumonia is associated with erythema multiforme?
Mycoplasma pneumonia
Define pneumococcal infection
Pneumococcal disease is a name for any infection caused by bacteria called Streptococcus** **pneumoniae.
What is a PE?
When blood clot in pulmonary arterial vasculature develops, usually from an underlying DVT of the lower limbs.
Give some risk factors for a PE
- Immobility
- Recent surgery
- Long haul flights
- Pregnancy
- Hormone therapy with oestrogen
- Malignancy
- Polycythaemia
- SLE
Every patient admitted to hospital should be assessed for their risk of VTE. If they are at increased risk of VTE they should receive prophylaxis with what?
low molecular weight heparin (LMWH) such as enoxaparin unless contraindicated
anti-compression stocking also used unless contraindicated
Give 2 main contraindications for LMWH
- Active bleeding
- Existing anticoagulation with warfarin or NOAC
What is the major contraindication for compression stockings?
Significant peripheral arterial disease
What is the typical triad of symptoms of a PE?
- Sudden onset SOB
- Pleuritic chest pain
- Haemoptysis
Massive PE → above + syncope/shock
Small PE → may be asymptomatic
What is the most common ECG sign of a PE?
Sinus tachycardia
12-lead ECG signs seen in a PE?
- Can be normal
- Can show sinus tachycardia
- Massive PE → evidence of right heart strain; P pulmonale, right axis deviation, RBBB, non-specific ST/T wave changes
Give some ECG changes seen in right heart strain
- P pulmonale
- right axis deviation
- RBBB
- non-specific ST/T wave changes
What is p pulmonale?
P pulmonale are big, tall, peaked P waves on ECG → indicates right atrial enlargement (e.g. PE)
Most common cause of right axis deviation?
Right ventricular hypertrophy
What may an ABG show in a PE?
- May be normal
- May show type 1 respiratory failure (hypoxia without hypercapnia) and/or respiratory alkalosis (due to hyperventilation 2ary to hypoxia)
Why may a PE cause anaemia?
due to haemoptysis
Describe the negative predictive value of a d-dimer test
Highly non-specific but has 95% negative predictive value (i.e. useful in ruling out PE if negative)
Describe CXR in PE
typically normal in PE
What is the diagnostic test of choice in a PE?
CT pulmonary angiogram (CTPA) → will show filling defect in pulmonary vasculature
What is the 1st line investigation in a PE in pregnancy?
Duplex US (instead of CTPA)
Why may a bedside echocardiogram be useful in a massive PE?
In order to assess suitability for thrombolysis
How can the Well’s score be used to guide further investigations for a PE?
If the Well’s score is 4 or less → measure d-dimer (this has a high negative predictive value but a low specificity so only useful if the clinical suspicion of a PE is low):
If the Well’s score is >4 → further diagnostic imaging is required
If the Well’s score is 4 or below and a d-dimer is performed, what does a low d-dimer mean? What does a raised d-dimer mean?
- A low d-dimer excludes a PE
- A raised d-dimer is an indication for diagnostic imaging (by CTPA or V/Q scan)
Immediate harmacological management of a PE?
- Thrombolysis (IV bolus of Alteplase) → indicated in massive PE
- Initial pharmacological management – start immediately before confirming diagnosis:
- 1st line → DOACs apixaban or rivaroxaban
- LMWH (e.g. enoxaparin, dalteparin) → alternative if DOACs not suitable, or in antiphospholipid syndrome
What are the long-term anticoagulation options for a PE?
- DOACs
-
Warfarin:
- Target INR is 2-3
- When switching to warfarin, continue LMWH for 5 days
- LMWH → First line treatment in pregnancy or cancer
Describe the length of coagulation in a PE with an obvious reversible cause
3 months
Describe the length of coagulation in a PE if the cause is unclear, there is recurrent VTE or there is an irreversible underlying cause e.g. thrombophilia
3+ months (or lifelong)
Describe the length of coagulation in a PE in active cancer
6 months
Give some causes of drug induced pulmonary fibrosis
- Amiodarone
- Nitrofurantoin
- Methotrexate