Respiratory Flashcards
What characterises the presentation of asthma?
Cough (worse at night)
Shortness of breath
Wheeze
What 3 factors contribute to airway narrowing in asthma?
- Bronchial muscle contraction
- Mucosal swelling/inflammation due to mast cell and basophil degranulation
- Increased mucous production
What kind of reaction is atopic asthma?
Asthma is a type 1 hypersensitivity reaction - IgE mediated release of histamine
Name some risk factors for developing asthma
- Atopy/family history of atopy
- Pollution i.e. living in an inner-city environment
- Prematurity and low birth weight
- Viral infections in childhood e.g. bronchiolitis
What often precipitates asthma?
- Cold air - drying of airways causes cell shrinkage which triggers an inflammatory response
- Exercise
- Emotion
- Allergens
- Smoking
- Infection
- Pollution
- NSAIDs
- Beta blockers
How can asthma present?
- Dyspnoea
- Wheeze + chest tightness
- Nocturnal cough
- Acid reflux (40-60%)
- Atopic disease
- Diurnal variation in symptoms - marked morning dipping of the peak flow
What signs would you see on examination of asthma?
- Tachypnoea
- Bilateral widespread polyphonic wheeze
- Reduced air entry
- Hyperinflated chest -> hyper-resonant percussion
- Accessory muscle use
What characterises a severe asthma attack?
PEFR = 33-50% predicted
Unable to complete full sentences
Pulse > 110 bpm
RR > 25/min
What characterises a life-threatening asthma attack? How do you differentiate between this and near-fatal asthma attack?
Life-threatening = PEFR < 33% predicted
- Silent chest
- Confusion
- Exhaustion
- Cyanosis (sats < 92%)
- Bradycardia
- PaO2 < 8kPa
- Normal CO2 (would expect it to be low in asthma attack due to hyperventilation so if it is normal it indicates failing respiratory effort)
Near-fatal = raised CO2
What would you see on spirometry in asthma?
Reduced FEV1/FVC ratio < 0.7 suggesting obstructive patter
Increased residual volume
15% improvement after beta2 agonists/steroids
What is cardiac asthma?
Pulmonary oedema (due to heart failure)
What diseases are associated with asthma?
- Atopic diseases
- GORD
- Churg-Strauss aka eosinophilic granulomatosis - first presents with asthma
- Allergic bronchopulmonary aspergillosis
What is the acute management of asthma?
O SHIT ME
Oxygen 15L/min via NRBM Salbutamol 5mg neb back to back Hydrocortisone 100mg IV or prednisolone 40mg PO for 5 days Ipratropium bromide 5mcg neb Theophylline Magnesium 1.2-2g IV over 20 min Escalate
Step 1 of asthma management in adults
Step 1: mild intermittent asthma - 100% PEFR
- Inhaled SABA PRN
- If used more than 3 times a week go to step 2
Step 2 of asthma management in adults
Step 2: daily symptoms - <80% PEFR
- SABA + inhaled corticosteroid e.g. beclometasone (max 2 puffs twice a day)
Step 3 of asthma management in adults
Step 3
- SABA + ICS + LABA
Step 4 of asthma management in adults
Step 4
- Increase ICS to medium dose
- If LABA helped, keep it, if not bin it and replace with LTRA
What is the biggest cause of COPD?
Smoking - 10-20% of heavy smokers
What else can cause COPD?
Alpha-1-antitrypsin deficiency - alpha-1-antitrypsin inhibits the destruction of the alveolar wall
Pollution
Recurrent infections
Comorbidities
- CVD
- Lung cancer
- Osteoporosis
- Muscle weakness
What is COPD?
A progressive disorder characterised by irreversible obstruction of the airways
Chronic bronchitis = productive cough most days of 3 months per year for 2 years
AND
Emphysema = enlarged air spaces with destruction of alveolar walls
Distinguish between pink puffers and blue bloaters
Pink puffers = emphysema
- increased ventilation to compensate for lack of surface area for gas exchange (decreased perfusion)
- breathless but not cyanosed
Blue bloaters = chronic bronchitis
- obstruction leads to increased residual lung volume
- so there is decreased ventilation but normal perfusion
- retain carbon dioxide so they rely on hypoxic drive to breathe = type 2 respiratory failure
- cyanosed but not breathless
What signs would you see on examination of COPD?
- Tachypnoea
- Flapping tremor
- Sitting in tripod position
- Pursed lip breathing for prolonged expiration
- Use of accessory muscles
- Hyperinflated barrel chest - decreased cricosternal distance
- Decreased lung expansion
- Hyper-resonant percussion
- Cyanosis
- Quiet breath sounds over bullae
- Signs of right heart failure e.g. ankle oedema
What are some complications of COPD?
- Acute infective exacerbations
- Cor pulmonale
- Hypertension
- Polycythaemia
What would an X-ray look like in COPD?
- Hyperinflated chest = more than 6 anterior ribs seen
- Flat hemidiaphragms
- Narrow heart
- Large pulmonary arteries
- Reduced vascular markings
What is the only intervention shown to improve life-expectancy with COPD?
Stopping smoking
What index assesses the severity of COPD?
BODE index
- BMI
- Obstruction to airflow - FEV1 < 80%
- Dyspnoea
- Exercise tolerance
In order to start a COPD patient on long-term oxygen therapy, what criteria must they fulfil?
One of:
PaO2 <7.3kPa on two readings more than 3 weeks apart (hypoxaemia whilst breathing room air and are clinically stable), and are non-smokers
PaO2 of 7.3-8kPa + one of evidence of end-organ damage due to hypoxia:
- Nocturnal hypoxia
- Polycythemia
- Peripheral oedema
- Pulmonary hypertension
Terminal illness
Go through the step-wise management of chronic COPD
Step 1…
• SABA (salbutamol) + SAMA (ipratropium)
• Continue SABA as patient goes up the steps but stop SAMA if LAMA is added
Step 2…
• For patients with FEV1 > 50%
add LABA (salmeterol) + LAMA (tiotropium)
• For patients with FEV1 < 50% add LABA + ICS (fluticasone) = seretide
Step 3…
• 3 month trial of LAMA + LABA + ICS (e.g. trimbo)
• If this does not work, revert to LABA + LAMA
Step 4…
• Long Term Oxygen Therapy (LTOT)
What is the 2nd most common cancer worldwide?
Lung carcinoma
What are the 2 histological divisions of bronchial carcinoma? What is the most common bronchial carcinoma?
Small cell (oat cell) lung carcinoma
Non-small cell lung carcinoma
- Squamous
- Adenocarcinoma
- Large cell
- Adenocarcinoma in situ
Adenocarcinoma is now the most common lung cancer (40%) - it used to be squamous cell lung carcinoma until the 80s
What does small cell lung cancer arise from?
Endocrine cells (Kulchitsky cells)
What type of lung cancer is more aggressive?
Small cell lung cancer
Grows rapidly and is highly malignant
70% are disseminated at presentation
Metastasise earlier in their course so often cannot be treated by surgery
What are the main symptoms of bronchial carcinoma (in order of most common) ? Also give some other examples of symptoms.
Cough - 80%
Haemoptysis - 70%
Dyspnoea - 60%
Chest pain - 40%
Weight loss, anorexia, lethargy
Recurrent pneumonia
How does an apical Pancoast tumour present?
Hoarseness of voice
Horner’s syndrome = ptosis, miosis and anhidrosis
Severe localised pain in the apex and shoulder
On auscultation of the chest, what sounds would be heard in lung cancer?
Monophonic wheeze due to partial airway obstruction
What is a potential life threatening complication of lung cancer? How does it present?
SVC obstruction due to mediastinal tumour
- Oedematous neck
- Stridor
- Dilated veins in the chest
What are some paraneoplastic syndromes that can be caused by small cell lung carcinomas?
Excess ACTH - Cushing’s
Excess ADH - SIADH (causes low sodium)
Lambert-Eaton syndrome
What might you see on a chest Xray of someone with lung cancer?
- Nodule - central = small cell, squamous cell; peripheral = adenocarcinoma, large cell
- Hilar enlargement
- Consolidation due to post-obstructive pneumonia
- Pleural effusion - particularly unilateral
- Atelectasis
- Bony metastases
If there is suspicion of lung cancer, what investigations should be carried out?
- Chest X-Ray - is it central or peripheral?
- CT scan - signs of malignancy
- PET scan
- Bronchoscopy and biopsy = confirmatory test
○ Bronchoscopy with transbronchial biopsy for central nodes
○ CT-guided transthoracic biopsy for peripheral nodes - CT scan of chest-abdo-pelvis for staging
- Lung function tests to check suitability for lobectomy
Who is most at risk of a primary spontaneous pneumothorax?
Tall, skinny, young males - rupture of subpleural bullae
What are the main causes of secondary pneumothorax
Connective tissue disease
- Marfan’s syndrome
- Ehlers-Danlos syndrome
Obstructive lung disease
- Asthma
- COPD
Infective lung disease
- TB
- Pneumonia
Fibrotic lung disease
- Cystic fibrosis
- Idiopathic pulmonary fibrosis
Neoplastic disease
- Bronchial carcinoma
What are the two groups of traumatic causes of pneumothorax? Give examples of each
Iatrogenic
- Insertion of a central line
- Positive pressure ventilation
Non-iatrogenic
- Penetrating trauma
- Blunt trauma with rib fracture
In women what is a risk factor for pneumothorax?
Endometriosis - occur during menstruation
How does it classically present?
Sudden onset of unilateral pleuritic pain with progressively worsening breathlessness
What signs would you find on examination of a pneumothorax?
- Reduced chest expantion expansion
- Hyper-resonant percussion note
- Reduced/absent breath sounds, with no added sounds
- Reduced vocal resonance
- Pulsus paradoxicus - pulse slows on inspiration
What additional signs would be seen in a tension pneumothorax?
- Tracheal deviation away from affected side
- Raised JVP
- Haemodynamic instability - low BP, high HR
- Distended neck veins (mediastinum is pushed over and compressing the great veins)
What is the most important investigation in a suspected pneumothorax?
Chest X-Ray - will show areas devoid of lung markings
don’t do a CXR in tension pneumothorax as it delays management
How do you treat a primary pneumothorax depending on the size?
Size < 2cm and/or patient is not breathless - consider discharge and review in 2-4 weeks
Size > 2cm - aspirate with 16/18G cannula in 2nd intercostal space mid-clavicular line under local anaesthetic
- If resolves and breathing improves, consider discharge and review in 2-4 weeks
- If doesn’t resolve, insert chest drain in 5th intercostal space mid-axillary line and admit patient
How do you treat secondary pneumothorax depending on the size?
Size < 1cm - admit and give high flow oxygen and observe for 24 hours
Size 1-2cm - aspirate with 16-18G cannula
- If successful and size now <1cm, admit for 24 hours and give high flow oxygen
- If unsuccessful, chest drain required
Size > 2cm - Chest drain in 5th intercostal space mid-axillary line
What are the different divisions of a pleural effusion?
Transudates - protein < 25g/L
Exudates - protein > 35g/L
Haemothorax = blood in pleural space
Chylothorax = lymph with fat in pleural space
Empyema = pus in the pleural space
Haemopneumothorax = both blood and air in pleural space
What causes a transudative pleural effusion?
Increase in venous pressure causing increased hydrostatic pressure
- Cardiac failure
- Constrictive pericarditis
Hypoproteinaemia causing reduced oncotic pressure
- Liver cirrhosis
- Nephrotic syndrome
- Malabsorption
- CKD
Others
- Hypothyroidism
- Meig’s syndrome - ascites, pleural effusion, benign ovarian tumour
What causes an exudative pleural effusion?
Increased leakiness of the pleural capillaries secondary to infection, inflammation and malignancy
Infection
- Pneumonia
- TB
Malignancy
- Bronchial carcinoma
- Lymphoma
- Mesothelioma
PE - Pulmonary infarction
Autoimmune
- Rheumatoid arthritis
- SLE
How does a pleural effusion present?
Small pleural effusions (<300ml) are often asymptomatic
OR
Dyspnoea
Pleuritic chest pain
Dry, non-productive cough
What signs might you see on examination of pleural effusion?
Palpation
- Decreased expansion
- Decreased tactile vocal fremitus
- Tracheal deviation away from effusion (mediastinal shift = effusion > 1L)
Percussion
- Stony dull percussion note
Auscultation
- Diminished breath sounds
- Decreased vocal resonance
- Bronchial breathing above the effusion where lung is compressed
What can be seen on a chest x-ray in pleural effusion?
Blunting of costophrenic angles - 200ml of fluid required to be seen
Meniscus-shaped margin
Large effusion (>1L)
- Complete opacification of the lung
- Mediastinal shift
- Tracheal deviation away from the effusion
What is used for diagnosis of the pleural effusion?
Diagnotic thoracentesis
- Percuss upper border of pleural effusion and choose a site 1 or 2 intercostal spaces below it
What cytology results would indicate what in pleural fluid analysis?
Neutrophils ++
- Pneumonia
- PE
Lymphocytes ++
- Malignancy
- TB
- RA, SLE, sarcoidosis
Mesothelial cells ++
- Pulmonary infarction
What clinical chemistry results would indicate what in pleural fluid analysis?
Protein
- <25g/L = transudate
- > 35g/L = exudate
Low glucose, low pH, high LDH
- Empyema
- Malignancy
- TB
- RA, SLE
Raised amylase
- Pancreatitis
What is calculated if the protein content of the effusion is equivocal (25-35g/L)? What levels are indicative of which type of pleural effusion?
Calculate Light’s Criteria
Transudative…
• Pleural fluid protein: serum protein ration < 0.5
• Pleural fluid LDH: serum LDH ratio < 0.6
• Pleural fluid LDH < 2/3 the upper limit of normal serum LDH
Exudative…
• Pleural fluid protein: serum protein ration > 0.5
• Pleural fluid LDH: serum LDH ratio > 0.6
• Pleural fluid LDH > 2/3 the upper limit of normal serum LDH
What are the most common organisms to cause a CAP?
- Streptococcus pneumoniae
- Haemophilus influenzae
- Moraxella catarrhalis
Name some atypical causes of CAP
Mycoplasma pneumoniae
Legionella
Chlamydia pneumoniae
What is HAP defined as?
Pneumonia 48 hours after admission (or 5+ days depending on trust) or has been in hospital in past month
What most commonly causes a hospital acquired pneumonia?
- Gram negative enterobacteria
- Staphylococcus aureus
- Pseudomonas
- Klebsiella pneumoniae
What are the main symptoms of pneumonia?
- Shortness of breath
- Cough
- Productive in adults - purulent sputum
- Often dry in infants/elderly or atypical pneumonia
- Sometimes haemoptysis
• Pleuritic chest pain - most painful on inspiration
- Fever, rigors
- Vomiting
What microbiological studies may be done in pneumonia?
Blood cultures
Sputum culture and gram stain
Legionella/Pneumococcal urinary antigens
What investigation is diagnostic of pneumonia?
Chest X-ray
What would loss of right heart border show?
Right middle lobe pneumonia
What severity score is used in pneumonia? Interpret each score
CURB-65
Confusion - AMTS < 8 Urea > 7mmol/L Respiratory rate > 30/min BP < 90/60 mmHg Age > 65
0-1 = PO antibiotics as an outpatient 2 = consider hospital admission 3 = definite hospital admission/consider ITU
What is the main cause of a PE?
Venous thrombosis from a deep vein of the leg/pelvis
Clots break off, pass through veins to the right side of the heart before lodging in a pulmonary artery
What types of emboli exist?
Septic emboli from endocarditis - IVDU Fat - long-bone fractures Air - surgery, trauma Neoplastic cells - prostate/breast cancers most commonly Parasites Amniotic fluid embolism Foreign bodies - IVDU, iatrogenic
List the main risk factors for PE
Recent surgery (abdo/pelvic/hip/knee) Pregnancy, COCP, HRT Leg fracture Thrombophilia e.g. antiphospholipid syndrome Reduced mobility Maligancy Previous PE Nephrotic syndrome
How does a PE present?
Sudden onset SOB
Pleuritic chest pain, worse on inspiration
Haemoptysis
Syncope
What signs might you find on examination of a PE?
- Pyrexia
- Cyanosis
- Tachypnoea
- Tachycardia
- Hypotension
- Raised JVP
- Pleural rub
- Pleural effusion
- signs of DVT
What investigation is both diagnostic and prognostic of a PE?
CTPA
What bloods must you do in suspected PE?
Bloods
- FBC
- Coagulation screen
- D-dimer
How might an ECG look in PE?
ECG
- Tachycardia
- Right bundle branch block
- Right axis deviation
- S1 Q3 T3 pattern - deep S wave in lead 1, Q wave inverted in lead 3, inverted T wave in lead 3
What other test is useful in PE?
V/Q scan to see if there is a ventilation-perfusion mismatch
What score assesses the clinical probability of a PE? What do the scores indicate and how do they affect your subsequent investigations?
Well’s score (if score is greater than 4, immediate CTPA or treat with LMWH)
- Clinical signs of DVT
- Pulse > 100 bpm
- Recent surgery
- Previous DVT
- Haemoptysis
- Cancer
- Alternative diagnosis is less likely than PE
Score < 4 = low-risk -> do D-Dimer, if positive do CTPA, if negative discharge
Score >4 = high-risk -> do CTPA
What is the treatment for PE?
If haemodynamically unstable, thrombolyse with alteplase
LMWH for 5 days
Unfractioned heparin if renal impairment
Then start DOAC or warfarin for 3 months
If unprovoked PE, continue anticoagulation for longer than 3 months.
If caused by malignancy, continue for 6 months
What pathological features are there in pulmonary fibrosis?
- Fibrosis and remodelling of the interstitium
- Chronic inflammation
- Hyperplasia of type II epithelial cells (the ones that secrete pulmonary surfactant to decrease surface tension within alveoli)
What are some risk factors for developing pulmonary fibrosis?
Smoking
Occupation - silica, asbestos, heavy metals, mouldy foliage
Chronic viral infections - hepatitis C, EBV
GORD with micro-aspiration
Drugs e.g. methotrexate, nitrofurantoin, amiodarone, bleomycin
Rheumatological conditions e.g. sarcoidosis, ankylosing spondylitis, RA, scleroderma
How does pulmonary fibrosis present?
Dry cough Exertional dyspnoea Malaise Weight loss Arthralgia
What signs would you see on examination of pulmonary fibrosis?
Clubbing in 50%
Bilateral fine end-inspiratory crepitations
Decreased chest expansion
What are the main complications of pulmonary fibrosis?
Respiratory failure
Increased risk of lung cancer
What are the diagnostic tests for pulmonary fibrosis?
Bronchoscopy
Lung biopsy
What would you see on CT scan of pulmonary fibrosis?
Honeycombing
Loss of architecture
Reticular abnormality
Interlobular septal thickening
What would spirometry show in pulmonary fibrosis?
Restrictive pattern i.e. FEV1/FVC > 0.7
How do you manage a patient with pulmonary fibrosis?
- Supportive oxygen therapy
- Flu vaccination
- High dose prednisolone
- Opiates for excessive cough in end stage disease
- Smoking cessation
- Palliative care
Why does hyperventilation lead to peripheral paraesthesia?
- Hydrogen ions and calcium are bound to serum albumin
- When blood becomes alkalotic, the bound hydrogen ions dissociate from albumin
- The albumin can bind with more calcium so there is less freely ionised calcium, leading to hypocalcaemia
What causes a type 1 respiratory failure?
V/Q mismatch
- Reduced ventilation but normal perfusion e.g. pulmonary oedema, bronchoconstriction
- Reduced perfusion but normal ventilation e.g. PE
Name 4 categories of causes of type 2 respiratory failure
- Increased resistance due to airway obstruction e.g. COPD
- Reduced compliance of lung tissue/chest wall e.g. rib fractures, obesity
- Reduced strength of respiratory muscles e.g. MND, Guillan-Barré
- Drugs acting on respiratory centre e.g. opiates
What is fluoroscopy used for in respiratory?
It is used to view the function and movement of lungs, diaphragm and chest movements
Used to check for masses in chest, obstruction, pleural effusions and loss of elasticity
What are the normal ranges on an ABG?
pH : 7.35-7.45 PaCO2: 4.7-6.0 PaO2: 11-13 HCO3-: 22-26 Base excess: -2 to +2
List some causes of a chronic cough (8+ weeks)
· Cigarette smoke · Use of ACE inhibitor · Asthma · Gastro-oesophageal reflux disease · COPD · Eosinophilic bronchitis · Post-nasal drip · Tumour – bronchial carcinoma, lymphoma, metastatic carcinoma
What is a MART?
Maintenance and reliever therapy (MART) = a form of combined ICS and fast-acting LABA treatment in a single inhaler
What are the side effects of beta-2 agonists?
Fine tremor
Headache
Muscle cramps
Palpitations
What is the MRC Dyspnoea Scale?
- Not troubled by breathlessness except on strenuous exercise
- Short of breath when hurrying or walking up a slight incline
- Walks slower than contemporaries on level ground because of breathlessness
or has to stop for breath when walking at own pace - Stops for breath after walk about 100m or after a few minutes on level ground
- Too breathless to leave the house or breathless on dressing/undressing
What are the different stages of COPD on spirometry?
Stage 1 = Mild - FEV1 ≥ 80%
Stage 2 = Moderate - FEV1 50-79%
Stage 3 = Severe - FEV1 30-49%
Stage 4 Very Severe FEV1 <30%
What are some contraindications to spirometry?
Recent MI
Current ACS
Recent thorax surgery
Haemoptysis
How would you treat a mild asthma attack?
Up to 10 puffs salbutamol inhaler
What is the management of a tension pneumothorax?
- Sit patient up
- Oxygen - high flow 15L/min NRBM
- Aspirate - 16/18G cannula in 2nd intercostal space mid-clavicular line
- Then insert chest drain in 5th intercostal space mid-axillary line
What is an open pneumothorax?
Large defect (>60% size of trachea) in chest wall When chest expands, air goes in through defect rather than down trachea No gas exchange in pleural space No tension
Give examples of what can cause hyperventilation
CNS infection Subarachnoid haemorrhage Panic attack Pulmonary emboli (through reflex hyperventilation) Aspirin overdose Any cause of hypoxia (through hyperventilation driven by peripheral chemoreceptors) Anaemia DKA initially
What medication can be given for COPD patients who struggle with thick phlegm?
Carbocisteine = mucolytic
What features are characteristic of aspiration pneumonia?
- Occurs in patients with unsafe swallow e.g. stroke, myasthenia gravis, achalasia
- R lung more commonly affected because right bronchus is wider and more vertical which facilitates passage of aspirate
What features are characteristic of klebsiella pneumonia?
- More common in immunocompromised, elderly, diabetics, alcoholics, malignancy
- Red-currant sputum
- Primarily affects upper lobes - causes cavitating pneumonia
- Gram-negative anaerobic rod
- Increased risk of empyema, lung abscess, pleural adhesions
What features are characteristic of staphylococcal pneumonia?
- Bilateral cavitating bronchopneumonia
* More common in IVDU, elderly patients or those who already have influenza infection
What features are characteristic of mycoplasma pneumonia?
- Presents with flu-like symptoms - arthralgia, myalgia, dry cough, headache
- Usually affects younger patients
- Can have auto-immune manifestation due to cold agglutinins causing autoimmune haemolytic anaemia
What are some potential complications of mycoplasma pneumonia?
Erythema multiforme
Stevens-Johnson syndrome
Guillain-Barre
Meningoencephalitis
What features are characteristic of chlamydophila psittaci pneumonia?
- Acquired from contact with infected birds, cattle, horse, sheep
- Can cause hepatitis, splenomegaly, nephritis, infective endocarditis, meningoencephalitis, rash
What is the empirical therapy for CAP in outpatients?
Antibiotics given for 5 days
Previously healthy pts -monotherapy with amoxicillin/doxycycline/macrolide
Patients with comorbidities
- Combination therapy: co-amoxiclav/cefuroxime + macrolide/doxycycline
What antibiotic is given for chlamydia pneumoniae?
Tetracyclines e.g. doxycycline
What antibiotic is given for legionella and pseudomonas?
Quinolone e.g. ciprofloxacin/levofloxacin
What are some potential complications of pneumonia?
Within days
• Pleural effusion
• Empyema - patient has partially recovered but then develops spike in temperature
• Lobar collapse - result of sputum retention
• VTE
• Pneumothorax - particularly with Staphylococcus aureus
Days to weeks
• Lung abscess
• Sepsis
• Respiratory failure, ARDS
Summarise the pathophysiology of sarcoidosis
Formation of non-caseating granulomas within the lungs and lymphatic system
A granuloma is a collection of WBCs (mononuclear cells and macrophages) , surrounded by lymphocytes, plasma cells, mast cells, fibroblasts, and collagen
What are the stages of chronic sarcoidosis based on CXR findings?
Stage 0 - normal findings (but positive bronchoalveolar lavage)
Stage I - bilateral hilar lymphadenopathy
Stage II - bilateral hilar lymphadenopathy with reticular or ground-glass opacities (peripheral infiltrates)
Stage III - bilateral reticular or ground-glass opacities without hilar lymphadenopathy
Stage IV - pulmonary fibrosis
How does acute sarcoidosis present? Also, what syndrome is a subtype of sarcoidosis with an acute presentation and what are the main features?
- General non-specific symptoms e.g. fever, malaise, anorexia, weight loss
- Breathlessness, cough and chest pain
Lofgren syndrome
• Highly acute presentation with FEVER and following triad:
1. Migratory polyarthritis - symmetrical arthritis that primarily affects the ankles
2. Erythema nodosum - primarily affects extensor surfaces of lower legs
3. Bilateral hilar lymphadenopathy
What are some extra-pulmonary manifestations of chronic sarcoidosis?
- Constitutional: fatigue, weight loss, arthralgia, and low-grade fever. Peripheral lymphadenopathy is most frequent extra-pulmonary manifestation
- Neurological: meningitis, peripheral neuropathy, bilateral Bell’s palsy
- Ocular: uveitis, keratoconjunctivitis sicca, blurred vision
- Cardiac: arrhythmias, restrictive cardiomyopathy.
- Abdominal: hepatomegaly, splenomegaly, renal stones.
- Dermatological: erythema nodosum, lupus pernio (purple skin lesions on nose, cheeks, chin, ears)
What is the gold standard test for diagnosis of sarcoidosis?
Bronchoscopy + biopsy - shows evidence of a non-caseating granuloma
What is the prognosis of the different stages of sarcoidosis?
Stage 0 and 1 – usually resolve spontaneously
Stage 2+ and acute disease – may improve with NSAIDs and bed rest
If a patient with sarcoidosis has extrapulmonary manifestations, what is the treatment?
Steroids (prednisolone 40mg for 4-6 weeks then taper dose over 1 year) - first line
Methotrexate - second line
Hydroxychloroquine - third line
Name some diseases that also feature non-caseating granulomas and are possible DDx for sarcoidosis
- Hodgkin lymphoma - alcohol-induced pain, pruritis, hx of EBV, Reed-Sternberg cells
- Non-Hodgkin lymphoma - lymphadenopathy, splenomegaly, bone marrow suppresion
- Pneumoconiosis - exposure to mineral dust, chronic cough, progressive exertional dyspnoea
- Granulomatosis with polyangiitis (Wegener’s) - chronic sinusitus with thick purulent discharge, treatment-resistant pneumonia, glomerulonephritis
What is the pathophysiology behind dormant TB?
Mycobacteria enter the alveoli where they are engulfed by alveolar macrophages and replicated within them - in most cases, the initial infection is contained in the lungs (hilar lymph nodes) by the immune system and does not spread so does not cause an acute illness
What area of the lung does TB usually affect?
Upper lobe
What are the main pulmonary symptoms of TB?
- Chronic productive cough +/- haemoptysis
* Shortness of breath
What is miliary TB?
Some patients’ immune systems are not able to contain the primary infection, and so it disseminates widely via the bloodstream
It is known as miliary TB due to the characteristic pattern on CXR like ‘millet-seeds’ when re-infection of lungs occurs after passing through circulation.
What is the second most affected organ system (after the lungs) in TB? How does it present?
Genito-urinary system
Sterile pyuria Kidney pathologies Abscesses Salpingitis and infertiltiy Epididymo-orchitis
What investigations are done in active TB?
- CXR
- 3 separate sputum samples including one early morning sample
- Samples are Ziehl-Neelsen stained - rapid direct microscopy for acid-fast bacilli
- For culture, Lowenstein- Jensen media is needed (takes 4-8 weeks due to slow bacterial growth and sensitivities take 3-4 weeks more)
What test screen people at high risk for TB? What causes false positives and false negatives?
Mantoux tuberculin skin test
- Tuberculin protein is injected into the dermis
- After 48-72 hours, level of inflammation is assessed by measuring diameter
False positives in previously immunised
False negatives in sarcoidosis, Hodgkin’s lymphoma
What test for latent TB is not affected by previous vaccination?
Interferon-Gamma Release Assays
Positive test indicates immune system has prior recognition of TB antigens = previous, latent or active TB
What is the treatment of TB?
Isoniazid, rifampicin, ethambutol and pyrazinamide for 2 months
Then isoniazid and rifampicin for a further 4 months
What are the side effects of isoniazid?
- Constipation
- Peripheral neuropathy - give pyridoxine to prevent this
- SLE-like symptoms
- Hepatitis
What are the side effects of rifampicin?
- Anorexia
- Pseudomembranous colitis
- Orange colouration of excreted bodily fluids
- Drug interactions (CYP450 inducer)
- Liver toxicity
What is the main side effect to be aware of of ethambutol?
Optic neuritis - red/green colourblindness
What are the side effects of pyrazinamide?
- Sideroblastic anaemia
- Arthralgia
- Hepatotoxicity
What are some risk factors for sleep apnoea?
• Obesity - especially around the neck - most important risk factor
• Alcohol consumption before sleep
• Sedative/beta-blocker use before sleep
• Smoking
• Family history
• Hypothyroidism
• Structural abnormalities that impair respiratory flow
○ Adenotonsillar hyperplasia - in children
○ Nasal septum deviation
○ Enlarged uvula, tongue, soft palate
○ Overbite with small chin
• Neuromuscular disease
What is the gold standard test for sleep apnoea?
Polysomnography:
- EEG
- Electro-oculogram to measure REM sleep
- Electromyogram to measure muscle movement
How many apnoeas per hour is diagnostic of sleep apnoea?
At least 5 apnoeas (>10 seconds without breathing) per hour + symptoms = diagnostic
Mild OSA = 1-14/hour
Moderate OSA = 15-30/hour
Severe OSA = >30/hour
What is the most effective intervention for sleep apnoea/
Weight loss
What is the therapy of choice for symptomatic sleep apnoea/
CPAP - delivered via a nasal mask or full face mask
Needs to be worn for 8 hours each night
What is the most common cause of bronchiectasis in developed countries and what is the most common worldwide?
Cystic fibrosis - developed countries
TB - worldwide
What is the main symptom of bronchiectasis?
Chronic cough \+/- Production of large amounts of foul smelling sputum \+/- Sputum may contain flecks of blood Worse in the mornings Can be brought on by changes in posture
What are the classic risk factors for carbon monoxide poisoning?
Recent house move Faulty/old boiler House fire Use of gas fire BBQ in tent to warm up Motor vehicle exhausts Poorly ventilated areas
By which mechanisms does an increase in carboxyhaemoglobin cause hypoxia?
The affinity of haemoglobin for CO is 240x stronger than for O2
Increased COHb causes hypoxia via:
- Decreased oxygen-carrying capacity of Hb
- Shift in O2 dissociation curve to the left, increasing affinity for O2 but decreasing release of O2 in tissue
- Binding of CO to myoglobin leading to cardiac ischaemia and decreased cardiac output
How does someone with carbon monoxide poisoning present?
- Headache, dizziness, fatigue, nausea/vomiting
- Altered mental status, seizures, loss of consciousness/coma
- Cherry-red lips
How do you diagnose carbon monoxide poisoning?
Abnormal COHb level on venous/arterial CO oximetry on ABG/VBG
>3-4% in non-smokers
>10-15% in smokers
Pulse oximeters cannot distinguish between COHb and oxyhaemoglobin so sats will appear normal!
What is the management for carbon monoxide poisoning?
Secure airway if necessary
100% Oxygen immediately via NRBM - continue giving until patient is asymptomatic for at least 6 hours and COHb level normalises
Fluids to improve perfusion
Where are mesothelial cells?
They line the body’s cavities e.g. pleura, peritoneum, pericardium, testes
What causes pleural mesothelioma?
Asbestos exposure
What are the most common symptoms of pleural mesothelioma?
Shortness of breath Chest pain (non-pleuritic)
What is the diagnostic investigation of pleural mesothelioma?
Pleuroscopy with stained biopsy - mesothelioma cells and psammoma bodies
How is pleural mesothelioma broadly managed?
- Radiotherapy +/- chemotherapy
* Pleurectomy or pneumonectomy in cases of severely impaired pulmonary function
What physio technique is commonly used to remove excess sputum?
Postural drainage - relies of effects of gravity to drain secretions from lung segments into the central airways where it can be removed via coughing techniques
