Obstructive airways disease

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Obstructive airways disease

• COPD
• Asthma
• Gordon Christie
• Consultant Respiratory Physician
• ARI

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Objectives

• Diagnosis assessment of severity
• Appropriate investigation
• When to refer
• Empirical treatment
• Chronic disease
• Acute exacerbations

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What is it?

• COPD

• Asthma

• No truly satisfactory definition
• Reversible airflow limitation
• Bronchial hyperreactivity
• Eosinophilic airflow inflammation

• Better defined
• Irreversible airflow obstruction
• Gradually progressive
• Inflammation
• Usually smoking associated

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Emphysema (Pathology)
Chronic Bronchitis (Symptoms)
COPD (Fixed airflow obstruction)
Asthma (Reversible Airflow obstruction)
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Epidemiology

• Asthma
• Point prevalence 8-10 in children, 5 in adults
• Severe disease much less common
• Complex genetic-environmental interaction
• COPD
• Point prevalence 1.5-2
• Much undiagnosed symptomatic disease
• Much asymptomatic airflow limitation (?5-8 of
  adult population)

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COPD Causation

• In the UK
• Overwhelmingly cigarette smoking
• Dose response relationship to smoking exposure
• Rare under 20 pack years
• Occupational dust exposure of minor ( declining)
  importance
• Some individuals at high genetic risk
• Alpha 1 antitrypsin deficiency
• Rare familial susceptibility
• Passive smoking of minor importance

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Impact on NHS Grampian

• Catchment population 560,000 (1 of UK)
• Relatively low deprivation

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Making a diagnosis

• Asthma
• Common at all ages
• Usually mild
• Usually variable symptoms
• Characterised by exacerbations
• May well be undiagnosed
• Usually frequent chest infections or
  bronchitis
• Smokers get pure asthma too !
• But may not respond to inhaled steroid nearly as
  well

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COPD

• Predominantly a disease of older adults
• Rare under 40
• Uncommon under 50
• Strong dose response relationship to smoking
  exposure
• Uncommon under 20 pack years

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Assessing the breathless patient

• Is there an existing diagnosis?
• Is it right??
• How breathless?
• MRC1Breathless on significant exertion
• MRC2Breathless on moderate exertion
• MRC3 Breathless walking with own age
• MRC4 Breathless on minimal exertion
• MRC5 Breathless at rest

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History

• Duration of breathlessness
• COPD long history, gradually progressive may
  require careful history taking to elicit
• Asthma classically symptom variability
• Often associated with triggers
• Nocturnal symptoms
• Exacerbations markers of severity/ instability
• Childhood symptoms/ school absence
• Often recurrent bronchitis or pneumonia

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Investigations

• Oximetry...hypoxaemia is bad
• Spirometry
• Fundamental
• If normal suspect asthma
• Peak flow
• Need to seek variability over time (at least 2
  weeks)
• More detailed pulmonary function
• Gas transfer
• 6 minute walk
• Chest X ray
• Primarily to exclude other diagnoses (LVF, ILD
  etc)

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Spirometry

• Severe airflow obstruction

• Normal (young, tall, male)

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Peak flow variability
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Peak flow

• Test for asthma
• Need 2 weeks or more recorded
• First 3-4 days can usually be discarded (practice
  effect)
• Look for 20 variability
• Some variability is physiological
• Look for morning dips dips with symptomatic
  periods
• Useful with trial of treatment
• But remember timescale of treatment effect

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Pulmonary function testing

• Main test of discriminant value is gas transfer
• Measure of lung parenchymal function
• Reduced (usually significantly lt50 predicted) in
  significant COPD
• Correlates with disease severity
• Normal or supranormal in asthma
• Functional tests primarily assess severity
• 6 minute walk
• Desaturation is ominous
• Shuttle walk
• Formal cardiopulmonary exercise testing
• Limited availability

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Other tests

• CXR Primarily to exclude obvious LVF, ILD etc.
• NOT a diagnostic test for airway disease!
• ECG Primarily to exclude IHD but remember RV
  changes
• Echocardiography
• Remember PA pressure/ RV hypertrophy dilatation
• HRCT
• Can be helpful assessing structural emphysema
  (normally unnecessary as diagnosis already made)
• Invaluable in assessment of interstitial lung
  disease

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Making a diagnosisCOPD

• Symptoms
• Exacerbations
• Smoking history
• Signs of hyperinflation clinically if severe
• Spirometry confirms obstruction correlates with
  severity
• Significant function limitation lt50 predicted
• Often housebound lt1 litre absolute FEV1
• Gas transfer may help if uncertain
• Beware pulmonary hypertension if advanced disease
• May merit echo, 6 minute walk
• HRCT rarely necessary

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Making a diagnosis Asthma

• Variable exertional breathlessness
• Childhood family history common
• History of precipitants (exercise, cats, cold,
  pollen, paint, perfume)
• Associated atopy (hayfever, eczema)
• Peripheral blood eosinophilia, raised total
  specific IgE
• Persistent symptoms (cough, sputum, wheeze) imply
  poor control
• Usually no signs on examination normal
  spirometry
• Peak flow variability common, trial of treatment
  useful
• Sometimes chronic airflow limitation
  indistinguishable from COPD but exercise
  tolerance better than expected from spirometry
  gas transfer preserved

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When to refer

• Early! (..the drugs take time to work)
• Concurrent with trial of empirical treatment
• Concurrent with requests for additional
  straightforward tests (pulmonary function, echo
  primarily)
• If real diagnostic doubt
• Poorly controlled disease (persistent symptoms,
  frequent exacerbations)
• Advanced disease
• COPD with low absolute FEV1, evidence of right
  heart failure
• Asthma with significant fixed airflow limitation

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When to treat empirically

• Majority of situations
• If convincing history evidence of airflow
  obstruction
• Response to treatment often helpful in secondary
  assessment
• With monitoring of outcomes (peak flow chart,
  review with repeat spirometry), usually after 6-8
  weeks treatment

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Empirical treatment

• Should be designed to achieve rapid results in
  context of preassessment
• Drugs are (generally) safe in short term at high
  doses
• Mainstay is inhaled corticosteroid
  (beclometasone, budesonide, fluticasone)
• Usually combined with long acting beta2 agonist
  (salmeterol, formoterol)
• Bronchodilator for symptom relief
• Salbutamol, terbutaline

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Inhalers made eas(ier)..

• Traditional pressurised MDIs...
• Deliver 10-15 dose to the lungs
• Delivered dose doubled by spacers
• Are difficult to use-require coordination
  timing
• Doses changing with CFC free inhalers
• Deposition patterns may change with CFC inhalers
  (smaller inhaled particles)
• Breath actuated devices (easibreathe etc.)
• Much liked by health economists extrapolating
  from RCTs, less favoured by patients their
  doctors

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Dry powder inhalers

• Better drug deposition (up to 30-35 delivered
  dose)
• Simpler to use (no requirement for timing)
• Effective even at low peak inspiratory flow
• Often preferred by patients
• Better range of combination inhaled steroid/ LABA
  products available

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Practical empirical treatment

• Start reliever bronchodilator (usually salbutamol
  200mcg as required)
• Start combined ICS/LABA
• Seretide (50-100-125-250-500 mcg fluticasone
  50mcg salmeterol)
• Symbicort (100-200-400 mcg budesonide 6-12 mcg
  formoterol)
• Monitor outcomes
• Peak flow (if asthma)
• Clinical review with repeat spirometry in 6-8
  weeks

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Treatment COPD

• COPD
• Recent trials
• TORCH (COPD, FEV1lt60 predicted RCT, n6000,
  placebo vs fluticasone 500 mcg bd alone vs
  salmeterol 50 mcg bd vs combined fluticasone
  500mcg-salmeterol 50mcg bd over 3 years)
• Exacerbations, lung function quality of life
  all improved with all active teatment
• Lung function improved with combination,
  salmeterol alone
• Effects of combination treatment additive
  compared to single drugs alone
• Borderline effect on mortality (p0.052!)
• Combination probably represents current standard
  of care
• Some concern about increased incidence of
  pneumonia over 3 year followup

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COPD Drug choices

• INSPIRE ICS/LABA vs Tiotropium (long acting
  anticholinergic bronchodilator)
• Both improved quality of life, lung function,
  reduced exacerbations
• Combination superior to tiotropium
• Cochrane review suggests combination treatment
  does not have mortality benefit
• Clear benefits in exacerbation frequency (down
  30-40), quality of life lung function
  (although latter are modest)
• UPLIFT Tiotropium vs placebo
• Reduction in exacerbation frequency improved
  quality of life
• No mortality benefit (P0.09)
• Increased rate of vascular death reported in US
  meta analysis of anticholinergic treatment in
  COPD (but not UPLIFT)
• No trials of combination ICS/LABA/long acting
  anticholinergic

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Other drugs

• Mucolytics
• 2 good trials (BRONCUS, PEACE) suggesting
  reduced exacerbation frequency in inhaled steroid
  naive only
• Much cheaper relevant in resource poor
  settings, less so in UK
• Theophylline
• Few good trials but extensively used
• Probably safer than was believed used at low
  doses no need to chase therapeutic drug levels
• Narrow therapeutic index
• Boutique theophyllines (rofilumilast,
  cilomilast on horizon)-unclear if additional
  benefit justifies expense
• Nebulisers
• Inefficient-delivered drug dose usually 5
• Useful acutely
• Not for maintenance treatment

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Pulmonary rehabilitation

• Usually physiotherapist led
• 10 week course, twice weekly sessions
• Variety of programmes but usually
• Exercise (circuits, upper body)
• Breathing control, pacing
• Education/ anticipatory care
• Smoking cessation
• Impressive effects
• Significant improvement in exercise function
• Improvement in quality of life (greater than drug
  effects)
• Shorter readmissions (though not necessarily
  fewer)
• Developing interest in acute pulmonary
  rehabilitation around acute exacerbations

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..so what do I do?

• ENCOURAGE SMOKING CESSATION!
• Brief advice
• Refer to local service
• Bronchodilator for symptom relief
• Combined inhaled steroid/ long acting
  bronchodilator
• Currently Seretide 500 bd via dry powder device
  (accuhaler) for simplicity concordance
• Probably a class effect
• Tiotropium
• Low dose theophylline (200mg bd) as next step
• Refer for pulmonary rehabilitation (where
  available)

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Treatment Asthma

• Empirical treatment
• Step 1 Bronchodilator only
• Step 2 Bronchodilator regular inhaled steroid
• Step 3 Add LABA (in practice combination
  inhalers, as in COPD) or theophylline or
  leukotriene receptor antagonist
• Step 4 Maximise inhaled steroid
• Step 5 Add regular oral steroid

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Empirical treatment

• Depends on previous treatment step current
  symptoms
• Aiming for good perioperative control
• Increase to BTS 3-4 if concerned
• Will usually take 2-4 weeks to see effect of
  additional drug 6-8 weeks to see effect of
  increased inhaled steroid
• GOAL study suggests that benefit of increasing
  ICS continues to increase over up to 12 months

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Asthma Other issues

• Treat nasal symptoms aggressively if present
  (one airway) in addition to lower airway
• Nasal steroid
• Leukotriene receptor antagonists
• Antihistamines
• Gastro oesophageal reflux also worth treating
  vigorously

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Acute exacerbations

• Asthma
• Oxygen
• Nebulised bronchodilators, add ipratropium if
  severe
• IV then Oral steroid (0.5mg/kg usually 30-40mg/
  day)
• Consider magnesium, possibly repeat if severe
• Consider IV aminophylline
• Antibiotics rarely indicated, some evidence of
  macrolides

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Acute exacerbations

• COPD
• Oxygen (controlled!)
• Nebulised bronchodilators
• Reasonable evidence for oral steroid
• Appropriate antibiotics
• Consider aminophylline
• NIV....

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NIV

• Good evidence for mortality benefit in acute
  exacerbations with hypercarbia
• Widely available can be used in ward setting
• Preferable to intubation in many circumstances
• Provides ventilatory support while other
  treatment works
• Not (routinely) for hypoxic respiratory failure
  in most circumstances

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Summary

• Diagnosis assessment of severity
• Appropriate investigation
• Empirical treatment
• Chronic disease
• Acute exacerbations
• When to refer