Download Obstructive Airwary Disease

OBSTRUCTIVE AIRWAY DISEASE
Asthma & COPD
Rachel Ventre FY1
SPIROMETRY/ PFT
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Obstructive –  FEV1/FVC ratio
Asthma
 COPD
 Bronchiectasis
 CF
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Restrictive – FVC & FEV1. Normal or  ratio.
Kyphosis/Scoliosis
 ILD
 Connective tissue diseases
 Infection - pneumonia
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DEFINITIONS
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Asthma

Common, chronic inflammatory airway disease,
characterised by variable (diurnal) reversible airflow
obstruction, airway hyper-responsiveness, bronchial
inflammation and bronchospasm.
AETIOLOGY
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Environment
maternal smoking during pregnancy
 low air quality (pollution)
 sterile environment (Hygiene hypothesis)
 occupational allergens (isocyanates, epoxy resins)
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Genetic
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FHx of atopy. +ve twin studies.
Asthma Triggers?
PATHOPHYSIOLOGY
3 main features:
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Airway narrowing – bronchiole constriction
Irritation – inflammation of mucosal lining
Blockage – excess mucous production forming plugs
EPIDEMIOLOGY
Increasing prevalence in UK
 FHx of atopy
 B>G 3:2 in children
but equal in adults
 Onset – any age
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Atopy?
Type I hypersensitivity to allergens
 Increased tendency for T lymphocyte’s to drive IgE
production on allergen exposure
 Associated with Asthma, Eczema and Allergic Rhinitis
(Hayfever). Runs in families.

PRESENTATION
Symptoms
Signs
Cough
Wheeze
Chest tightness
Occasional sputum production
Dyspnoea (mild – severe)
Pattern  worse at night,
exacerbated by exercise, cold,
allergens and physiological
stress. Drugs (NSAIDs and
βblockers)
• Common allergens  animal
dander, cats, dust mites, flour,
paints, varnishes and detergents
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Tachypnoea
Accessory muscle use
Audible wheeze polyphonic
Hyperinflated chest
Hyperesonant percussion
Reduced air entry
Prolonged expiratory phase
INVESTIGATIONS
Initial Dx & assess severity
Bedside:
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PEFR – with diary showing diurnal variation (>20%), morning dip
Pulse oximetry
Blood:
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ABG – acidotic?
Eosinophil levels, Aspergillus antibody
FBC (WCC), CRP, U&E
Blood and sputum cultures
Radiology:
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CXR – hyperinflation, pneumothorax, pneumonia?
Special tests:
 Pulmonary function tests
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FEV1/FVC < 80%
Spirometry – Flow volume loop showing obstructive picture
15% improvement post – salbutamol
Skin prick tests – allergen identification
BTS uses a ‘response to therapy’ approach to asthma Dx.
Chronic monitoring: PEFR – best comparison
MANAGEMENT
Conservative:
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Smoking cessation
Check inhaler technique
Patient education – avoid allergens/precipitants
Emergency plan – acute exacerbations
Vaccinations – pneumococcal and influenza
Medical: BTS guidelines

Start at appropriate level for severity. Move up if
necessary and step down if good control for 3 months.
Rescue steroids if required in exacerbations.
STEPWISE RX
ACUTE ASTHMA
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Acute exacerbations are common
Medical emergency
Responsible for 1000-2000 deaths/yr
?
?
MANAGEMENT
Resuscitate  ABCDE
 Monitor O2 sats, ABG and PEFR
 High flow 100% Oxygen (15L via non-rebreathable mask) aim sats
94-98%
 Nebulisers
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Systemic corticosteroids
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hydrocortisone 100-200mg IV then Prednisalone 40mg PO for 5/7
Magnesium sulphate 2g over 20mins IV
Bronchodilators IV (ITU only, need cardiac monitoring)
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SABA (Salbutamol 5mg continuously then 2-4hourly) + Ipatropium Bromide
0.5mg QDS
Aminophylline or Salbutamol
Assess severity (ventilation)
Consider ITU or intubation if worsening hypoxia and PEFR despite Rx
Hypercapnia, resp acidosis, coma, resp drepression/arrest. Also if patient is
tiring!
 Consider patient performance status (poor  poor ITU prognosis)
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Rx underlying cause – infection (ABx) or pneumothorax.
DEFINITIONS

COPD

Chronic progressive lung disorder, characterised by
(mostly) irreversible airflow obstruction, FEV1
<80% predicted and FEV1/FVC ratio <70%.
Chronic bronchitis = clinical
 Cough & sputum, most days, 3/12 over 2years
 Chronic inflam of bronchi (medium)
 Emphysema = histopathological, CXR/CT changes
 Permanent destructive enlargement of airspaces
 Distal to terminal bronchioles (alveolar) = bullae

AETIOLOGY
Bronchial and alveolar damage caused by
environmental toxins
 Cigarette smoking


Process not fully understood. Processes causing lung
damage include:
Persistent airway inflammation
Oxidant/antioxidant capacity
imbalance
Protease/antiprotease imbalance
in lungs

Cytokine release due to inflammation, body
responds to irritant particles
Oxidative stress produced by high free radical
concentration in tobacco smoke
Smoke and free radicals impair activity of
antiprotease enzymes (e.g. Alpha 1 antitrypsin).
Proteases damage lung.
Genetic

Alpha 1 antitrypsin deficiency (<1%)  Emphysema
EPIDEMIOLOGY
Very common, many undiagnosed
 More common in lower socioeconomic status
(relates to smoking prevalence)
 Presents in middle age or later
 M>F due to smoking tendencies in past

PRESENTATION

Symptoms

Chronic productive cough
Following colds and in winter months
 Increase severity and frequency over time
 Sputum – can be blood stained in advanced disease

Recurrent respiratory infections
 Exertional dyspnoea & reduced exercise tolerance
 Regular morning cough
 Wheeze

PRESENTATION

Signs:
Inspection
Percussion
• Wheeze on forced expiration
• Tracheal tug
• Tracheal descent in inspiration,
reduced cricosternal distance
• Accessory muscle use
• sternocleidomastoid and scalenes
• Suprasternal and supraclavical
fossae excavation (prominent)
• Indrawn costal margins and
intercostal spaces
• Pursed lip breathing
• hyperinflation/barrel chest
• Increased AP diameter
• Weight loss
• Central cyanosis
• CO2 flapping tremor and bounding
pulse (hypercapnia)
• Hyper-resonant percussion
• Loss of liver and cardiac dullness
Auscultation
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Quiet breath sounds
Prolonged expiration
Wheeze
Crepitations if infected
INVESTIGATIONS
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Bedside:
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PEFR – reduced
Blood:
Secondary polycythaemia
 ABG - Hypoxia, normal or raised CO2
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Radiology:
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CXR
Chest CT – bullae and lung volumes
Special tests:

Pulmonary function tests
Spirometry – reduced FEV1 <80%
 FEV1/FVC ratio – reduced <70% (see below)
 Increased lung volumes
 CO gas transfer coefficient decreased when significant alveolar
destruction
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ECG/Echo – cor pulmonale?
 Sputum/blood culture
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CXR
• Hypertranslucent lung
fields
• Low flat diaphragm
• Bullae
• Hyperinflation
• >6ribs ant
•  peripheral lung
markings
• Elongated cardiac
shadow
DIAGNOSIS/SEVERITY
4 classifications of severity of COPD:
MANAGEMENT

Conservative:

Avoid bronchial irritation
Smoking cessation  limits FEV1 decline
 Occupational allergens
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Exercise
 Pulmonary rehabilitation
 Weight loss – correct obesity, nutritional improvement
 Rx depression/social isolation – often associated

MANAGEMENT - MEDICAL
MANAGEMENT

Surgery:
Lung transplant in lung patients with alpha 1
antitrypsin deficiency
 Bullaectomy
 lung volume reduction surgery (Lobectomy – now
close off the lobe using a filter)
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ACUTE COPD MX
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Rescusitation – ABCDE
24% O2, 2L via nasal cannula or non-variable flow venture mask.
If Type II resp failure target 88-92%
Nebulisers - bronchodilators
Corticosteroids (oral/IV)
Fluids
Theophylline IV
Empirical ABx IV if infection (+/- pseudomonal cover? Tazocin,
Meropenum, Gentamycin)
Consider ventilation
Consider NIV, intubation or ITU in severe cases.
Indication for NIV  persistent hypercapnia type II RF,
deterioration despite 1hr best medical Rx and patient tiring.
VIDEO BY ASTHMA UK
PEFR
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http://www.youtube.com/watch?v=DxBDfqPmaZ
U
VIDEO ASTHMA UK
INHALER TECHNIQUE
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MDI
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http://www.youtube.com/watch?v=FqztOZLqFhE
All other inhalers
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http://www.asthma.org.uk/knowledge-banktreatment-and-medicines-using-your-inhalers
LTOT
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Indications:

Chronic hypoxaemia e.g COPD, ILD, Lung Ca
PaO2 <7.3kPa on air when clinically stable
 PaO2 7.3-8kPa if 2* polycythaemia or pulmonary hypertension
(clinical/echo)
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Nocturnal hypoventilation
e.g obesity, OSA, chest wall disease
 Specialist referral. Usually with CPAP or NIV.
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Palliative care
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For Rx of dyspnoea in terminal illness.
Assessed by respiratory physiologists
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requires ABG on and off O2.
ANY QUESTIONS
REFERENCES
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BTS guidelines asthma - http://www.britthoracic.org.uk/Portals/0/Guidelines/AsthmaGuidelines/qrg101%2020
11.pdf
BTS guideline COPD http://www.nice.org.uk/nicemedia/live/13029/49399/49399.pdf
BTS guidlein LTOT - http://www.britthoracic.org.uk/Portals/0/Clinical%20Information/Home%20Oxygen%
20Service/clinical%20adultoxygenjan06.pdf
Spirometry guideline - http://www.britthoracic.org.uk/Portals/0/Clinical%20Information/COPD/COPD%20C
onsortium/spirometry_in_practice051.pdf
Asthma UK
Patient.co.uk – professional
Acutemed.co.uk
http://www.eguidelines.co.uk/eguidelinesmain/gip/vol_13/aug_10/jone
s_copd_aug10.php#.UlqCeBDZIa8
Good books for finals: Clinical cases uncovered