Respiratory Flashcards
Name 4 organisms that commonly cause respiratory infections in patients with cystic fibrosis.
Staph aureus
Pseudomonas aeruginosa
Burkholderia cepacia
Aspergillus
What is the Epworth Sleep Scale out of, and what is considered normal?
Out of 24; up to 10 is normal
What are the three key features of obstructive sleep apnoea syndrome?
Snoring
Apnoeas
Daytime somnolence
How do you distinguish obstructive sleep apnoea from central sleep apnoea?
CSA - periods of absence of respiratory effort, versus attempts to overcome obstructed upper airway
What happens in REM sleep that results in less use of respiratory ventilatory muscles and decreased sats?
Skeletal muscle paralysis - this also stops you acting out your dreams during REM sleep
Name 8 conditions associated with restless leg syndrome.
Iron deficiency
ADHD
Coeliac disease
COPD
Depression/panic disorders
Fibromyalgia
Parkinson’s disease
Multiple sclerosis
Name 5 (groups of) medications that can cause restless legs syndrome?
SSRIs
Neuroleptics
Lithium
Beta blockade
Dopamine antagonists
Following conservative treatments, what medications can you give for restless legs syndrome? Name 7.
Iron replacement
Levodopa
Ropinirole
Clonazepam
Tramadol
Oxycodone
Gabapentin
What is the pathophysiology of narcolepsy, and what are the two different types?
Acquired deficiency of orexin (hypocretin) in key hypothalamic neurons
Type 1 - narcolepsy with cataplexy
Type 2 - narcolepsy without cataplexy
Diagnosed by REM intrusions on PSG
How is narcolepsy treated? Name 3 drugs.
Modafinil - treats narcolepsy but not cataplexy
Methylphenidate - treats both
Dexamphetamine - treats both
Anti-cataplectic include venlafaxine and clomipramine
Name 7 absolute contraindications for receiving a lung transplant?
Recent history of malignancy
Major organ dysfunction
Chronic infection with virulent or resistant microbes that are poorly controlled pre-Tx
BMI > 35
Current or repeated non-adherence to treatment
Severely limited functional status with poor rehabilitation potential
Name two conditions where single lung transplant can be indicated.
ILD
COPD
Single lung transplant recipients will generally be older, and they will not have an infection.
Name 4 conditions where bilateral lung transplants can be indicated.
Cystic fibrosis
Bronchiectasis
Pulmonary hypertension
Severe infection
Bilateral lung transplant recipients will be young patients
When could COPD patients get listed for a lung transplant? Name 5 stipulations.
BODE 7 or greater
FEV 15-20%
3 or more exacerbations in one year
One episode of acute hypercapnic respiratory failure
Moderate to severe pH
When could pulmonary fibrosis patients be listed for a lung transplant? Provide 4 stipulations.
Decline in FVC >10% and DLCO >15% in the prior 6 months
Development of pulmonary hypertension
Hospitalisation because of respiratory decline, acute exacerbation or pneumothorax
Significant exercise associated desaturation or requirement for oxygen
When could pulmonary vascular disease patients be listed for a lung transplant? Provide 3 stipulations.
NYHA functional class III or IV despite escalating pulmonary vasodilator therapy
Refractory or progressive right heart failure
Right heart catheter measurements of mean right arterial pressure >15 mmHg, cardiac index <2 litres/minute/m2 and mean PAP >50 mmHg
When could cystic fibrosis patients be listed for a lung transplant? Provide 7 stipulations.
Frequent hospitalisation
FEV1 <30% of predicted especially if rapid downward trajectory
Increasing antibiotic dependence or resistance
Life-threatening haemoptysis or pneumothorax
Requirement for non-invasive ventilation
Development of pulmonary hypertension
PCO2 > 50 mmHg and/or pO2 <60 mmHg (need for NIV)
What is the greatest limitation to survival in lung transplant patients?
Chronic allograft lung dysfunction
Which hypoventilation syndrome has an association with CVD?
Central sleep apnoea
Name 4 risk factors for developing CTEPH
Pro-coagulant states (antithrombin, protein C and S deficiency)
Lupus anticoagulant and APS
Blood groups A, B and aB
Splenectomy
CTEPH patients require lifelong anticoagulation
What is the definitive treatment for CTEPH?
Pulmonary endarterectomy
Procedural mortality is 2-5%, and the operation should be done at an expert centre where 20/year are performed
What sweat chloride test result is diagnostic of cystic fibrosis?
> 60 mmol/L
40-60 is in between normal and abnormal
What is the definitive test for primary ciliary dyskinesia?
Examination of ciliary ultrastructure under electron microscopy
Expect to see abnormal ultrastructure and slow ciliary beat frequency
How is cystic fibrosis diagnosed?
Clinical features of CF or family history of CF
AND EITHER
2 CF-causing mutations OR
Positive sweat chloride on 2 occasions OR
Nasal potential difference tracing typical for CF
What is nasal potential difference?
Test for CF
Voltage correlates with movement of Na across a cell membrane; amiloride blocks epithelial Na channels; isoprotenerol stimulates CFTR
CF patients have:
A more negative baseline potential difference
Larger inhibition after addition of amiloride
Little or no change with addition of Cl free solution or isoprotenerol
What is the inheritance of cystic fibrosis, and what is the most commonly involved gene?
Autosomal recessive
Deletion on long arm chromosome 7
Delta F508
What is ivacaftor?
Treatment for CF with gene mutation G551D
Class 3 defect - CFTR reaches cell surface but channel opening is impaired
Class 4 defect - decreased conductance
Ivacaftor is a small molecule potentiator of the CFTR channel
What is lumacaftor?
CFTR corrector
Used in combination with ivacaftor for homozygous Phe508del
Small improvement in FEV1 but significant decrease in pulmonary exacerbations
What is the benefit of macrolides in cystic fibrosis?
Inhibits biofilm production
Modifies mucous production
Suppresses inflammatory markers
Indicated for CF and non-CF bronchiectasis with pseudomonas or frequent exacerbators without pseudomonas
What constitutes significant bronchodilator reversibility on spirometry?
Improvement of 12% and/or 200ml
What does exhaled nitric oxide on PFTs help to indicate?
Whether or not there is inflammation present that might be responsive to steroids
Correlates with Th2 inflammation and sputum eosinophilia
What 4 parameters are used in the GOLD ABCD assessment tool for COPD?
FEV1 (predicted) - 1 is >80, 2 is 50-79, 3 is 30-49, 4 is <30
Exacerbation Hx - A or B is 0 or 1 (not leading to hospital admission), C or D is >2 or >1 leading to hospital admission
mMRC questionnaire - A or C or 0 or 1, B or D is >2
CAT questionnaire - A or C is CAT < 10, B or D is CAT >10
What are the 4 parameters used for the BODE index in COPD?
BMI
Obstruction - FEV1
Dyspnoea - mMRC dyspnoea scale
Exercise capacity - six-minute walk distance
Which gene is responsible for the onset of alpha-1-antitrypsin deficiency?
SERPINA1
What is the pathophysiology of alpha-1-antitrypsin deficiency?
Failure to inhibit neutrophil elastase in lung
Build up of AAT polymers in liver cells
When is long term oxygen therapy indicated for COPD patients?
Non-smoking stable COPD patients who have:
PaO2 < 55
PaO2 < 55-59 with evidence of pulmonary hypertension or polycythaemia
Note - no evidence of improved outcomes in COPD patients with moderate hypoxia
Name 5 benefits of pulmonary rehabilitation.
Improved exercise capacity
Reduced perceived intensity of breathlessness
Improved health-related quality of life
Reduced hospitalisation and hospital days
Reduced anxiety and depression in COPD
Name 7 bacteria that can be seen in bacterial exacerbations of COPD.
H influenza
Strep pneumoniae
M catarrhalis
Mycoplasma
Chlamydia
In more severe disease - Staph aureus, Pseudomonas
When would you consider referral for lung transplants in COPD patients? Name 5 considerations.
When the majority of the following are present…
Progressive symptoms, despite maximal treatment including medication, pulmonary rehabilitation and oxygen therapy
Patient is not a candidate for endoscopic or surgical lung volume reduction surgery
BODE index of 5-6
PaCO2 > 50 and/or PaO2 < 60
FEV1 < 25% predicted
What is a DECAF score, and what are its constituent parts?
Predictor of in-hospital mortality from COPD exacerbations
Dyspnoea
Eosinopaenia
Consolidation
Acid anemia
Atrial fibrillation
Score of 0-1 low risk; 2 intermediate risk; 3-6 high risk
Which vaccinations are recommended for COPD patients?
Influenza
Pneumococcal
When would you consider adding an ICS to treatment for COPD?
If FEV1 < 50%
2 or more hospitalisations within a year
All despite LABA and LAMA therapy
Name 4 viruses that can cause viral exacerbations of COPD
Influenza
Rhinovirus
RSV
Metapneumovirus
Name the main 3 cell types and cytokines that are involved in the pathogenesis of asthma.
Cells
- Th2 cells
- mast cells
- eosinophils
Cytokines
- IL-4
- IL-5
- IL-13
What are the pathological processes that occur in asthma? Name 5.
Mucosal inflammation
Mucoid exudate
Goblet cell metaplasia
Epithelial basement membrane thickening
Smooth muscle hypertrophy, hyperplasia and contraction
How is asthma diagnosed on spirometry?
FEV1 increase >200ml and >12% from baseline post bronchodilator
What does an increased exhaled nitric oxide test suggest on spirometry?
Suggests steroid-responsive airway disease.
What are the stages of treatment for asthma?
Stage 1 - SABA as required
Stage 2 - Low dose regular preventer (ICS) + SABA as required
Stage 3 - Low dose combo regular preventer (LABA + ICS) + reliever as required
- budesonide/formoterol (low dose) maintainence-and-reliever therapy
- ICS/LABA combo (low dose) as maintenance
Stage 4 - High dose combo regular preventer (LABA + ICS) + reliever as required
- budesonide/formoterol maintenance (medium dose) and reliever (low dose) therapy
- ICS/LABA combo (moderate-high dose) as maintenance therapy
Stage 5 - specialised treatments
What is SMART therapy for asthma?
Single Inhaler Maintenance and Reliever Therapy (SMART)
Budesonide/formoterol combination inhaler, 2 puffs BD and PRN
Used in moderate-to-severe asthma
What is omalizumab, and what stipulation is required to use it?
Anti-IgE - mAb that binds the Fc portion of IgE to prevent if from activating the high-affinity IgE receptor on mast cells, basophils and dendritic cells
Used in asthma principally
Baseline IgE needs to be <1300 IU/mL, otherwise too much IgE to bind
What is the main adverse effect of omalizumab?
Anaphylactoid reactions
What is mepolizumab?
Anti IL-5 - mAb that reduces production and survival of eosinophils
Used in severe asthma; reduces exacerbations and has a steroid-sparing effect
Name 2 drugs that can be used for the treatment of IPF?
Pirfenidone
Nintedanib
Name 4 features on HRCT consistent with usual interstitial pneumonia
Pleural/subpleural predominance
Traction bronchiectasis
Reticular shadowing
Honeycombing
Name 6 conditions associated with lymphocytic interstitial pneumonia.
Sjögren’s syndrome
Rheumatoid arthritis
HIV infection
SLE
Myasthenia Travis
Chronic active hepatitis infections
Name 2 features on HRCT of lymphocytic interstitial pneumonia.
Discrete peribronchovascular cysts
Varying degrees of ground glass opacities
Note - lot of overlap with NSIP, gold standard of diagnosis is biopsy
What are the two different types of NSIP that can be seen?
Cellular
Fibrotic
What features would you expect to see on HRCT with hypersensitivity pneumonitis? Name 3 features.
Upper zone predominant
Fine nodules (starry sky) with airway involvement
Inspiratory/expiratory scans demonstrate segmental air trapping and hence mosaic ventilation patterns
What are the features of cryptogenic organising pneumonia on HRCT?
Pleurally based
Dense consolidation in triangular, pleural areas
Air bronchograms
Peribronchovascular densities
What is pulmonary lymphangioleiomyomatosis?
A diffuse bilateral cystic disease that is either sporadic or associated with tuberous sclerosis complex
Associated with angiomyolipomas of the kidneys and meningiomas
Management is with mTOR inhibitors or lung transplantation
Name 2 radiographic patterns on HRCT associated with smoking.
RBILD (respiratory bronchiolitis-associated interstitial lung disease)
DIP (desquamative interstitial pneumonia)
DIP is a later presentation and likely represents the end stage of RBILD
What are the features on HRCT you would expect to see with RBILD (respiratory bronchiolitis-associated interstitial lung disease)? Name 5.
No zonal predominance
Bilateral
Prominent ground glass
Bronchial wall thickening
Coexisting centrilobar emphysema
Name 3 epidemiological factors associated with Langerhans cell histocytosis X (LCHC).
Young adults (20-40)
Smokers
Male > female
Name 4 features/disease associations with Langerhans cell histocytosis X.
Diabetes insipidus
Lytic bone lesions
Lymphoma
Pituitary hormone deficiencies
Where does CT prove to be more beneficial than PET scanning when looking for malignancy lung nodules?
When nodules are small (<0.7cm)
Also with bronchoalveolar Ca and carcinoid, as these exhibit low uptake
Name 2 confounding factors that can result in increased nitric oxide upon exhalation testing.
URTI
Air pollution exposure
Name 4 confounding factors that can result in decreased nitric oxide upon exhalation testing.
Steroids
Leukotriene receptor antagonists
Exercise
Smoking
Name 2 bacteria that are strongly linked to sarcoidosis.
Mycobacteria
Proprionibacteria
What are the characteristic findings on CT of sarcoidosis? Name 4.
Mediastinal and hilar lymphadenopathy
Lung disease with upper lobe predominance
Peribronchial irregularities
Subpleural micronodules
What is found on histology for sarcoidosis?
Non-caseating granulomas
Occasionally necrosis
What is the treatment for sarcoidosis.
50-60% of cases spontaneously remit
Corticosteroids for severe or progressive disease
Immunosuppressive treatment if steroid failure
- methotrexate is slow-acting, may take up to 6 months for benefit
- cyclophosphamide is treatment of choice for CNS sarcoidosis
- antimalarials have a role in skin, splenic involvement and hypercalcaemia
What are the characteristic features of bronchiectasis on HRCT? Name 3.
Airway dilatation
Bronchial wall thickening
Mucous plugging of airways - with tree-in-bud pattern
What is the alveolar gas equation?
paO2 = FiO2 (pATM - pH2O) - (paCO2 (1 - FiO2 (1 - RER)))/RER
paO2 = alveolar partial pressure of O2
FiO2 = fraction of inspired gas that is O2 (0.21)
pATM = prevailing atmospheric pressure (usually 760 at sea level)
pH2O = water vapour pressure (usually 47 at sea level)
paCO2 = partial pressure of carbon dioxide
RER = respiratory exchange ratio (0.8)
Simplified version, putting the numbers in, assuming sea level: 150 - (paCO2 x 1.25)
What does peptostreptococcus typically cause?
Empyemas - anaerobic infection
Foul tasting sputum is characteristic
