Respiratory Lectures Flashcards
Define FEV1.
Volume forcibly expired after maximal inspiration within 1 second.
Define FVC.
Total volume forcibly expired after maximal inspiration.
What is a normal FEV1?
> 80% of predicted FEV1.
What is an abnormal FEV1?
<80% of predicted FEV1.
What is a normal FVC?
> 80% of predicted FVC.
What is an abnormal FVC?
<80% of predicted FVC.
What does a low FVC indicate?
Airway restriction.
Define airway obstruction using FEV1 and FVC. (3)
1) FEV1/FVC < 0.7 (low)
2) FEV1 < 0.8 (low)
3) FVC > 0.8 (normal)
Define airway restriction using FEV1 and FVC. (3)
1) FEV1/FVC > 0.7 (normal)
2) FEV1 < 0.8 (low)
3) FVC < 0.8 (low)
Define type 1 respiratory failure. (2)
1) low pO2
2) low/normal pCO2
What can cause type 1 respiratory failure?
Pulmonary embolism.
Define type 2 respiratory failure. (2)
1) low pO2
2) high pCO2
What can cause type 2 respiratory failure?
Hypoventilation.
What is an easy way to remember the difference between type 1 and type 2 respiratory failure?
1) type 1 has 1 partial pressure change (low pO2)
2) type 2 has 2 partial pressure changes (low pO2 and high pCO2)
List 3 general causes of respiratory failure.
1) impaired ventilation
2) impaired perfusion
3) impaired gas exchange
List 5 signs of hypercapnoea (high CO2).
1) bounding pulse
2) flapping tremor
3) confusion
4) drowsiness
5) loss of consciousness
Define transfer co-efficient.
Ability of oxygen to diffuse across alveolar membrane.
How can transfer co-efficient be measured?
1) small amount of CO inspired
2) breath held for 10 seconds
3) CO transferred is measured
List 5 causes of a low transfer coefficient.
1) COPD (inc. emphysema)
2) fibrosing alveolitis
3) idiopathic pulmonary fibrosis
4) pulmonary hypertension
5) anaemia
What is a cause of a high transfer coefficient?
Pulmonary haemorrhage.
What two things generally coexist in COPD?
Chronic bronchitis and emphysema.
What V/Q is found in chronic bronchitis?
V/Q mismatch.
What V/Q is found in emphysema?
Matched V/Q deficit.
Describe how chronic bronchitis leads to heart failure. (4)
1) alveolar hypoxia
2) pulmonary shunting
3) pulmonary hypertension
4) cor pulmonale
What causes early onset COPD?
Alpha-1-antitrypsin deficiency.
How is chronic bronchitis defined?
Clinically.
Define chronic bronchitis.
Cough with sputum for 3 months for 2 years running.
How is emphysema defined?
Histologically.
Define emphysema.
Enlarged acini distal to terminal bronchioles with alveolar destruction.
What can patients not have both of? (2)
1) chronic obstructive pulmonary disease
2) asthma
List 2 types of asthma.
1) allergic/atopic/extrinsic (70%)
2) non-allergic/non-atopic/intrinsic (30%)
Where are IgEs produced in atopic asthma?
Systemically.
Where are IgEs produced in non-atopic asthma?
Locally.
List the atopic triad. (3)
1) asthma
2) atopic dermatitis
3) allergic rhinitis
What type of helper t-cells are predominately found in healthy lungs?
T helper 1 cells - cell mediated immunity.
What type of helper t-cells are predominately found in asthmatic lungs?
T helper 2 cells - humoral mediated immunity.
List the asthmatic triad. (3)
1) airway obstruction
2) airway hyperresponsiveness
3) airway inflammation
What type of hypersensitivity reaction is asthma?
Type 1 (IgE mediated).
What are peak expiratory flow measurements compared to? (2)
1) normal values based on height and gender
OR
2) past measurements
What age of onset asthma is associated with a more genetic cause?
Childhood.
What age of onset asthma is associated with a more environmental cause?
Adult.
Define silent chest.
Inability to generate enough airflow to wheeze due to fatigue/exhaustion.
How is ADAM33 cause asthma? (2)
1) airway hyperresponsiveness
2) tissue remodelling
List 2 foods that protective against asthma.
1) fruit
2) veg
What drug should you never prescribe to asthmatic?
Beta-blockers.
What is a good indicator of mast cell activity and why?
Tryptase, its only found in mast cells.
How do corticosteroids affect eosinophils?
Decrease eosinophil activation.
List 5 types of lung cancer.
1) lung adenocarcinoma (45%)
2) lung squamous cell carcinoma (25%)
3) lung small cell carcinoma (20%)
4) lung large cell carcinoma (10%)
What is small cell lung carcinoma also known as?
Oat cell carcinoma.
What percentage of small cell lung carcinomas present with metastasis?
67%.
List 3 hormones secreted by small cell lung carcinoma.
1) PTH
2) ADH
3) ACTH
List 7 substances that are occupational risk factors for lung cancer.
1) asbestos
2) coal
3) arsenic
4) chromium
5) nickel
6) petroleum products
7) iron oxide
What lung cancer is most associated with smoking?
Lung squamous cell carcinoma.
What cells are lung squamous cell carcinomas associated with?
Keratin producing epithelial cells.
What lung cancer is most common in non-smokers?
Lung adenocarcinoma.
List 6 common metastasis sites of lung cancers.
1) pleura
2) lymph nodes
3) bone
4) brain
5) liver
6) adrenal
What is the main lung lymphoma?
BALToma (bronchus associated tissue lymphoid tissue lymphoma —> B cells).
What is more common a primary or secondary lung cancer?
Secondary lung cancer.
List 4 organs whose cancers commonly metastases to the lungs.
1) kidney
2) breast
3) bowel
4) bladder
What is the most common cancer to metastases to the lungs?
Renal cell carcinoma.
What percentage of lung tumours are paraneoplastic?
10%.
Define hypertrophic pulmonary osteoarthopathy.
Condition characterised by clubbing, periostitis, arthropathy.
What triad characterises hypertrophic pulmonary osteoarthropathy?
1) digital clubbing
2) periostitis (esp. of small hand joints - DIP, MCP)
3) arthropathy (esp. of large joints - knee)
Define paraneoplastic syndrome.
Syndrome due to humoral (hormones, cytokines) factors secreted by tumour cells or immune cells against tumour cells
List 5 paraneoplastic complications of lung cancer.
1) hypercalcaemia (PTH)
2) SIADH (ADH)
3) Cushing’s syndrome (ACTH)
4) hypertrophic pulmonary osteoarthropathy (VEGF)
5) DIC
Define superior vena cava syndrome.
Partial blockage or compression of the superior vena cava.
List 3 treatments of superior vena cava syndrome.
1) stent
2) radiotherapy
3) dexamethasone
List 3 symptomatic treatments of airway narrowing.
1) tracheal stunting
2) cryotherapy
3) brachytherapy
What percentage of pleural mesotheliomas are caused by pulmonary asbestosis?
20%.
What is the latency period between asbestos exposure and mesothelioma development?
20-40 years.
What is the average time between diagnosis and death in mesothelioma?
8 months.
In what lung cancer are all deaths reported to the HM coroner?
Mesothelioma.
List 2 lung cancers found centrally.
1) lung small cell carcinoma
2) lung squamous cell carcinoma
List 2 lungs cancers found peripherally.
1) lung large cell carcinoma
2) lung adenocarcinoma
What is the triad in Horner’s syndrome?
1) miosis
2) ptosis
3) anhidrosis
What are the ECG changes in pulmonary embolism? (3)
S1, Q3, T3
1) prominent S wave in lead 1
2) prominent Q wave in lead 3
3) inverted T wave in lead 3
What percentage of DVTs cause PEs?
51%.
Why do you check for atrial septal defects after a pulmonary embolism?
1) patient at risk of emboli stroke
2) embolus can bypass lungs —> systemic circulation —> brain
Define pulmonary infarction.
Necrosis of lung tissue due to ischaemia.
What should you suspect in a patient who collapses 1-2 weeks after surgery?
Pulmonary embolism.
Where do the most clinically relevant pulmonary embolisms occur from?
DVTs from abdominal and pelvic veins.
What is the 5 year survival rate of idiopathic pulmonary fibrosis?
50%.
What should you not administer in idiopathic pulmonary fibrosis?
High dose steroids.
Describe basal and subpleural reticulation and honeycombing.
Net and honeycomb appearance of the lung base and between pleura and body wall.
List 4 types of interstitial lung disease.
1) idiopathic pulmonary fibrosis
2) sarcoidosis
3) hypersensitivity pneumonitis
4) asbestosis
Define interstitial lung disease.
Fibrosis distal to terminal bronchioles.
What organs does sarcoidosis generally effect? (4)
1) lungs*
2) lymph nodes (esp. hilar)
3) skin
4) eyes
How are Afro-Caribbeans affected by sarcoidosis?
More severely, with more extra-thoracic manifestations.
List 2 hormones realised by sarcoidosis granulomas.
1) ACE
2) calcitriol —> hypercalcaemia
What sarcoidosis patients should not be treated? (3)
1) symptomatic stage 1
2) asymptomatic stage 2
3) asymptomatic stage 3
What sarcoidosis patients should be treated? (3)
1) symptomatic stage 2
2) symptomatic stage 3
3) stage 4
Define lupus pernio.
Hardened purple plaques on forehead, nose, cheeks, lips, ears.
What percentage of cystic fibrosis has lung and GI involvement?
80%.
What percentage of cystic fibrosis has only lung involvement?
15%.
What is the cause of death in majority of cystic fibrosis patients?
Respiratory disease.
What is a general presenting feature of children with cystic fibrosis?
Recurrent respiratory infections.
Define meconium ileus.
Bowel obstruction due to thickened meconium - 1st stool.
What’s the median survival rate of cystic fibrosis in the UK?
41 years old.
List 5 professionals involved in a cystic fibrosis MDT.
1) general practitioner
2) physician
3) physiotherapist
4) specialist nurse
5) dietician
List 6 features of Mycobacterium tuberculosis.
1) bacilli (rods) 2 aerobic 3) non-motile 4) non-sporing 5) thick waxy capsule 6) slow growing (15-20 hour generation)
Why does Mycobacterium tuberculosis form granulomas?
Resistant to macrophage phagocytosis.
List 2 stains of Mycobacterium tuberculosis.
1) Ziehl-Nielsen stain - red/pink (acid-fast bacilli)
2) Gram stain - weakly positive (purple) (high lipid cell wall)
What percentage of latent tuberculosis reactivate?
10%.
What part of the GI tract can be affect ed by tuberculosis?
Ileocaecal valve.
List 4 lymph nodes associated to tuberculosis.
1) hilar
2) mediastinal
3) paratracheal
4) subclavicular
List organs other than the lungs that can be affected by tuberculosis
1) gastrointestinal
2) spinal (Pott’s vertebrae)
3) CNS (meningitis and high ICP)
4) genitourinary
5) cardiac (esp. pericardium)
6) skin (lupus vulgaris)
What is another name for the tuberculin skin test of latent TB?
Mantoux test.
Describe timeline of tuberculosis sputum diagnosis. (3)
1) sputum NAAT - <8 hours
2) sputum smear - <24 hours
3) sputum culture - 1-3 weeks (liquid media), 4-8 weeks (solid media)
Is testing for latent TB good?
No, both tuberculin skin test and interferon gamma release assays have a false negative of 20-25%.
When should TB be considered in chronic illness?
Fever and weight loss present.
Why is neonatal BCG no onset offered?
Not cost effective.
Define Ghon focus.
Initial subpleural caseating granuloma in tuberculosis.
Define Ghon complex.
Subpleural and associated lymph nodal caseating granulomas in tuberculosis.
Define Ranke complex.
Calcified subpleural and associated lymph nodal caseating granulomas in tuberculosis.
List 5 mechanisms the upper respiratory tract has against infection.
1) cough reflex
2) mucus
3) mucocillary escalator
4) surface secretions (e.g. defensins, complement)
5) immune system
List 2 upper respiratory tract infections that difficult to differentiate between.
1) tonsillitis
2) pharyngitis
What is an important differential diagnosis of tonsillitis?
Glandular fever.
What antibiotics can Haemophilus influenza be resistant to?
Amoxicillin.
What age does epiglottis generally present.
<5 years old.
What age does whooping cough generally present?
<5 years old.
Why does the use of acid-reducing drugs (e.g. PPI or H2a) increase the risk of pneumonia?
Decreased gastric acid secretion allows bacteria to colonise the upper respiratory tract.
What is better at diagnosing pneumonia, x-ray or CT scan?
CT scan.
List 3 reasons that an x-ray is preferred to a CT scan when diagnosing pneumonia.
1) cheaper
2) less radiation
3) bedside testing
Why aren’t blood/sputum MS&Cs required investigations in community acquired pneumonia?
Good prognosis with empirical antibiotics.
Define empirical therapy.
Therapy based on experience, i.e. educated clinical guess.
List 3 macrolide antibiotics.
1) azithromycin
2) clarithromycin
3) erythromycin
Define lung abscess.
Pus filled cavity within lung parenchyma.
Define empyema.
Pus within pleural space.
What is the difference between empyema and lung abscess?
Pus in pleural space (empyema), vs pus in lung parenchyma (lung abscess).
List 2 tests that repeated if pneumonia worsens.
1) chest x-ray
2) CRP
What is the mortality of CAP with a CURB-65 ≥3?
15-40%
When is there a follow up for pneumonia?
6 weeks ± chest x-ray.
Define ventilator associated pneumonia.
Pneumonia >48 hours after endotracheal intubation (type of HAP).
How many serotypes of Streptococcus pneumoniae does the pneumococcal vaccine protect against?
23.
What is another name for thoracentesis?
Pleural tap.
Define consolidation.
Lung tissue filled with fluid instead if air.
List 3 occasions when ITU is considered in pneumonia.
1) shock
2) hypercapnia
3) persistent hypoxia
What is the mortality of HAP?
21%.
What percentage of CAP is caused by viral infections?
15% (esp. Haemophilus influenzae).
Define hospital acquired pneumonia.
New onset purulent productive cough with chest x-ray consolidation signs in patients hospital admitted greater than 48 hours ago.
What is the second most common hospital acquired infection after UTI?
HAP.
Why does pneumonia generally not respond well to penicillin?
Most causative pathogens of pneumonia don’t have cell walls.
Absence of what type of symptoms is indicative of pneumonia?
Upper respiratory tract symptoms (e.g. rhinorrhoea).
List 4 upper respiratory tract symptoms.
1) rhinorrhoea
2) sore throat
3) odynophagia
4) dysphagia
Why is a chest x-ray repeated 2-3 days later if CAP is clinically suspected but not radiologically confirmed?
Radiological abnormalities lag behind clinical signs.
What is type I respiratory failure also known as?
Hypoxia respiratory failure.
What is type II respiratory failure also known as?
Hypercapnic respiratory failure.
What is the mnemonic for respiratory failure symptoms? (4)
A) anxiety
B) breathlessness
C) confusion
D) drowsiness
What does CPAP stand for?
Continuous positive airway pressure.
What is the aim of respiratory failure treatment?
Correct hypoxia.
Why should you be careful administering oxygen in type II respiratory failure? (4)
1) patient may have lost hypercapnic drive (e.g. COPD)
2) patient relying on hypoxic drive
3) administering oxygen dampens hypoxic drive
4) patient loses ability to breathe
What is the ABG in metabolic acidosis? (3)
1) low pH
2) low HCO3-
3) normal PaCO2
What is the ABG in metabolic alkalosis? (3)
1) high pH
2) high HCO3-
3) normal PaCO2
What is the ABG in respiratory acidosis?
1) low pH
2) normal HCO3-
3) high PaCO2
What is the ABG in respiratory alkalosis?
1) high pH
2) normal HCO3-
3) low PaCO2
What produces and reabsorbs pleural fluid?
Parietal pleura.
Where does the majority of pleural fluid reabsorption occur?
Posteriorly and inferiorly.
What is the parietal pleura highly sensitive to?
Pain.
List 4 substances that pleural effusions can rarely contain.
1) air - pneumothorax
2) blood - haemothorax
3) lymph - chylothorax
4) pus - empyema
List 3 appearances of pleural fluid in diagnostic thoracentesis and what they mean.
1) purulent - empyema
2) turbid - infected
3) milky - chylothorax
Define parapneumonic effusion.
Pneumonia with associate pleural effusion.
Define diaphoresis.
Sweating.
Define tension pneumothorax.
Pneumothorax displaces mediastinal structures, significantly impairing gas exchange and/or blood circulation.
How long does a 50% pneumothorax collapsed lung take to reabsorb?
40 days.
Define bronchopleural fistula.
Long term communication between lung and pleural space.
When should you not request a chest x-ray in pneumothorax?
If it is a tension pneumothorax.
What needs to be immediately carried out in a tension pneumothorax patient?
Needle aspiration.
List 2 alternative names for a tube thoracostomy.
1) chest tube
2) chest drain
Define apnoea.
Temporary cessation of breathing.
Why is surgery carried out in obstructive sleep apnoea?
To release pharyngeal or nasal obstruction.
What tests are involved in polysomnography for diagnosing obstructive sleep apnoea? (5)
During sleep:
1) pulse oximetry
2) airflow at nose and mouth
3) electrocardiogram
4) electromyogram
5) abdominal wall movement
Define somnolence.
Strong desire to sleep.
Define pleurodesis.
Adhesion of parietal and visceral pleura - prevents effusion re-accumulation.
Define intercostal space retraction.
Intercostal muscles pull ribs in.
List 4 types of causes of hypersensitivity pneumonitis.
1) bacteria
2) fungi
3) animal proteins (esp. avian)
4) chemicals (e.g. acid anhydrides)
List 5 conditions at that can make up occupational lung disorders.
1) acute bronchitis
2) pulmonary fibrosis
3) asthma
4) hypersensitivity pneumonitis
5) lung cancer
Inhalation of coal dust particles for how long leads to coal-workers pneumoconiosis?
15-20 years.
List 5 occupations associated with silicosis.
1) stonemasons
2) sand-blasters
3) pottery
4) ceramic workers
5) foundry workers
What is the chest x-ray pattern in silicosis? (2)
1) diffuse nodular in upper and mid zone
2) thin streak calcification of hilar nodes
What type of asbestos is most likely to cause asbestosis?
Crocidolite.
Define plasmapheresis.
Removal of anti-GBM antibodies from blood.
What are anti-GBM antibodies?
Autoantibodies to alpha-3 chain of type IV collagen found in Goodpasture’s syndrome.
What ethnicity is predominately affected by Wegener’s syndrome?
Caucasian (90%).
