Dr Rickbir Singh Randhawa FY1 Definition Asthma Chronic inflammatory airway disease characterised by reversible airway obstruction airway hyperresponsiveness and bronchial inflammation Three factors contribute to reversible airway narrowing ID: 774904
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Slide1
Respiratory Medicine:Asthma and COPD
Dr Rickbir Singh Randhawa
FY1
Slide2Definition:Asthma
Chronic inflammatory airway disease characterised by
reversible airway obstruction
, airway hyper-responsiveness and bronchial inflammation.
Three factors contribute to reversible airway narrowing:
1. Bronchial smooth muscle contraction triggered by a variety of stimuli
2. Mucosal swelling/inflammation caused by mast cell and basophil degranulation- release of inflammatory mediators
3. Increased mucus production
Slide3Definition:COPD
Chronic progressive lung disorder characterized by
airway obstruction with little or no reversibility.
It includes the following:
Emphysema:
defined histologically as permanent destructive enlargement of air spaces distal to the terminal bronchioles
Chronic Bronchitis:
defined clinically as a chronic cough with sputum production on most days for 3 months per year over 2 successive years.
Slide4AetiologyAsthma
Genetic factors-
+VE family Hx, atopic (eczema, allergic rhinitis), linkages to multiple chromosomal locations genetic heterogeneity
Environmental triggers-
Allergens (House dust mite, pollen, pets (fur)), cigarette smoke, viral URTI, occupational allergens (isocyanates-spray paints, epoxy resins-adhesives/fibreglass fabrics)
Slide5PathophysiologyAsthma
Type 1 hypersensitivity reaction in atopic asthma
Early phase (up to 1 hour)
After exposure to inhaled allergen in a presensitized individual results in cross linking of IgE antibodies on the surface of mast cells. Release of inflammatory mediators-bronchial smooth muscle contraction (bronchoconstriction), mucous hyper secretion and airway oedema and obstruction.
Late phase (after 6-12 hours)
Recruitment of
eosinophils
,
basophils,neutrophils
and Th2 lymphocytes results in the perpetuation of the airway inflammation and bronchial hyper-responsiveness.
Slide6Aetiology/Risk factorsCOPD
Bronchial and alveolar damage due to environmental toxins-
smoking (cigarette smoke)
Indoor
air pollution (such as solid fuel used for cooking and heating
)
Outdoor
air
pollution
Occupational
dusts and chemicals (
vapours
, irritants, and fumes
)
Frequent
lower respiratory infections during
childhood.
Rare cause is
α
1-antitrypsin deficiency (<1%) consider in non smokers or in younger patients
Slide7HistoryAsthma
Intermittent wheeze
Breathlessness (dyspnoea)
Cough (often nocturnal)
Occasionally sputum
Diurnal variation in symptoms/ peak flow- morning dips of peak flow recordings
Slide8HistoryAsthma: Precipitating factors
Cold air
Exercise
Allergens (house dust mite, pollen, pets-animal fur)
Emotions
Smoking/passive smoking exposure
Viral URTI
Hx of
atopy
(eczema/
hayfever
-allergic rhinitis)
FHx
Drugs (Beta blockers, NSAIDS-
ask OTC meds
)- OSCE !
Slide9HistoryAsthma: things to also ask!
Precipitating factors if present
C
ompliance with medication
R
eliever usage (inhaler) – gauge severity
O
ccupational Hx-cause
S
leep- interference? Severity
S
moking Hx
E
czema/
hayfever
-
atopy
D
ays off school/work – gauge severity
Remember
CROSSED
mnemonic!
Slide10HistoryCOPD
Chronic breathlessness
Chronic Cough/sputum production
Wheeze
Smoker!
Minimal diurnal variation in symptoms compared to asthma
Age of onset >35 years (
Rare cause is
α
1-antitrypsin deficiency (<1%) consider in non smokers or in younger
patients)
Slide11Clinical signs O/E
Asthma
COPD
TachypnoeaUse of accessory muscles of respirationHyper inflated chest (reduced chest expansion)Hyper resonant percussion noteReduced air entryPolyphonic wheeze
Tachypnoea
Use of accessory muscles of
respiration
Purse lip breathing
Hyper inflated chest (reduced chest expansion)
Hyper resonant percussion
note
Reduced air entry-prolonged expiration
Wheeze, crackles if infective exacerbation
cyanosis
Slide12Severity of Asthma
Moderate exacerbation:
Increasing symptoms
PEF >50-75% of best or predicted
No features of severe asthma
Severe exacerbation:
Unable to complete sentences in one breath
PEF 33-50% of best or predicted
RR ≥ 25/min
HR ≥110/min
Slide13Severity of Asthma
Life threatening attack: Any of
PEF <33% of best or predicted
Silent chest
Cyanosis
Feeble respiratory effort
Hypotension
Exhaustion/confusion/coma (CO2 retention)
ABG:
normal or high CO2 (normal PaCO2 4.6-6.0
k
P
a
)
PaO2 <8kPa/O2
sats
<92%
Low pH <7.35 acidosis (CO2 retention)
Slide14Severity of COPD
Severity
FEV1 (% predicted)
Mild
≥80%
But FEV1/FVC <70%
Moderate
50-79%
Severe
30-49%
Very Severe
<30%
Slide15InvestigationsAsthma
Acute exacerbation:
Peak flow- PEF reading to classify the severity
Basic Obs include pulse oximetry- classify severity
ABG-respiratory failure
CXR- exclude differentials i.e. pneumothorax, pneumonia
Bloods- FBC (raised WCC infective exacerbation),
U+E’s,
CRP
Blood culture (febrile)
Sputum culture
Slide16InvestigationsAsthma
Chronic Asthma:
PEF monitoring with peak flow diary- diurnal variation >20% on ≥3days a week for 2 weeks with morning dips in readings.
Pulmonary function test- obstructive defect with improvement of FEV1 usually >15% improvement after a trial of a Beta 2 agonist.
Bloods- eosinophilia, raised IgE levels in atopic asthma.
Skin prick tests- help identify any allergens
Aspergillus antibody titres- for allergic aspergillus lung disease
Slide17InvestigationsCOPD
Acute exacerbation:
ABG- respiratory failure
Bloods- FBC (raised WCC infection),U+Es, CRP
Bloods cultures if febrile
Sputum culture
CXR –exclude differential i.e. pneumothorax, pneumonia
ECG-
cor
pulmonale right axis deviation (RVH)
Slide18InvestigationsCOPD
Chronic COPD:
Spirometry/pulmonary function tests- obstructive defect FEV1/FVC <70% also with FEV1<80% predicted
CXR- normal or show lung hyperinflation( >6 anterior ribs seen, flat hemi-diaphragms), large central pulmonary arteries, decreased peripheral vascular markings
ABG- hypoxia and/or hypercapnia
Bloods- FBC (increased
Hb
and PCV due to secondary polycythaemia secondary to hypoxia).
ECG and echocardiogram-
cor
pulmonale, pulmonary hypertension
α
1-antitrypsin levels- in young patients or with minimal smoking Hx
Slide19Obstructive vs Restrictive defectSpirometry/PFT
FEV1
FVC
FEV1/FVC
Obstructive
lung disease
Decreased (<80%)
Decreased
Decreased
(<0.7)
Restrictive lung disease
Decreased
Decreased (<80%)
Normal
(>0.7) or increased
Slide20ManagementAcute life threatening Asthma
Start Rx before Ix ABCDE!
O
xygen 15L NRB- sit patient up, 02
sats
94-98%/intubate
S
albutamol- 5mg Nebulised, back to back Nebs
H
ydrocortisone 100mg IV
I
pratropium bromide 0.5mg nebulised
T
heophylline (aminophylline) IV
Magnesium sulphate 2mg IV if no improvement
Remember
OSHIT
! Mnemonic
Normal or high CO2 is a very worrying sign- get early anaesthetic/ITU r/v
Slide21Management Chronic AsthmaChronic Asthma
Slide22Chronic Asthma Management
Asthma
Management The BTS Stepwise
Approach
Rx started at the step most appropriate to the
severity
STEP 1: SABA
STEP
2
: Step
1 + ICS
STEP
3: Step 2 + LABA &/or ↑ ICS dose
STEP
4
: Step
3 +
leukotriene receptor antagonist (
montelukast
)/theophylline
STEP
5: Step 4 + oral
steroids- refer to asthma clinic
Step down Rx if symptom control is good for >3 months
Educate on proper inhaler techniques and routine monitoring of peak flow.
Develop an individual
Mx
plan to avoid triggers
Slide23Management Acute exacerbation COPD
ABCDE approach!
Controlled oxygen therapy 24-28%
Venturi
mask vary according to ABG- target
sats
88-92%
Nebulized bronchodilators- salbutamol 5mg (back to back NEBS) and
ipratopium
bromide 0.5mg (4-6 hourly)
Steroids- IV hydrocortisone 200mg or PO prednisolone 40mg (7-14 days)
Abx
- if evidence of infection see local guidelines
NIV- if severe respiratory acidosis or medical Rx shows no improvement e.g. BIPAP- type 2 respiratory failure
Slide24Management Chronic COPD
Non Pharmacological
Mx
Smoking
Cessation
Nutrition- Rx poor nutrition e.g. fortisips
Obesity- healthy diet/lifestyle, regular exercise
Pulmonary Rehabilitation- graded exercise therapy to increased exercise tolerance
Slide25Chronic Management COPD
Slide26Chronic Management COPD
Mucolytics- aid chronic productive cough
CBT/Antidepressants- chronic illness
Criteria for LTOT:
Only for those stopped smoking-
fire risk!
PaO2<7.3
kPa
clinically stable- this value should be stable on two occasions >3 weeks apart
PaO2 7.3-8.0
kPa
with signs of pulmonary hypertension/
cor
pulmonale
Terminally ill patients
Surgical
Mx
- bullectomy (recurrent pneumothoraces), lung volume reduction surgery
Slide27Inhalers-Quick run through
SABA-e.g. salbutamol (
ventolin
) “blue inhaler”
LABA-e.g.
salmeterol
(
serevent
)
SAMA- e.g.
ipratopium
bromide (
atrovent
)
LAMA-e.g.
tiotropium
bromide (
spiriva
)
IC Steroids:
Becotide
(
beclometasone
),
Pulmicort
(budesonide),
Flixotide
(fluticasone)
Combination ICS:
Seretide (
fluticastone
+
salmeterol
)
Symbicort
(budesonide +
formoterol
)
Slide28Inhaler: Explaining how to use it
1. Remove the dust cap from the inhaler device.
2. Shake the device. Remember the canister holds a suspension of drug, and this needs to be shaken to ensure a uniform distribution of the drug particles.
3. If you have not used the inhaler for a week or more, or it is the first time you have used the inhaler, spray it into the air before using it to check that it works.
4. Hold the inhaler upright with you forefinger on the top of the canister.
5. Breathe out as far as is comfortable.
6. Place the mouthpiece in your mouth between your teeth, and close your lips around it.
7. Start to breathe in slowly and deeply, and at the same time, activate the inhaler by pressing down on the canister. When the canister is pushed down, a valve delivers a measured dose of drug in a fine mist.
8. Hold your breath for as long as is comfortable, then breathe out as normal.
9. If you are instructed to take 2 puffs, wait for about 30 seconds and repeat this process.
10. Do not release two puffs at the same time. This will increase the likelihood of deposition at the back of the throat and reduce the amount of drug reaching the lungs.
11. Finally, replace the cap on the inhaler.
Slide29Clinical scenario
A 64 year old gentleman presents to A&E with increasing SOB over the last 3 days. This is associated with a cough productive of thick, green sputum. He has a past medical history of “asthma”, but he has smoked 50 cigarettes a day for the past 40 years. On examination he is
tachypnoeic
,
tachycardic
, O2
sats
85% on air, he is using his accessory muscles to breathe. Auscultation reveals bilateral diffuse coarse
crepitations
and widespread wheeze
Slide30Questions
What are your main differential diagnoses for this
gentleman?
How would you investigate this gentleman?
Initial
management in acute setting?
Long-term management?
Can you tell me about the pathophysiology of COPD?
ie
. Clinical and
histopathological
definitions
Can you tell me some risk factors for COPD?
What are the criteria for mild, moderate, severe and very severe COPD?
What are the criteria for use of long term oxygen therapy (home oxygen)?
Slide31THANK YOU FOR LISTENING
ANY QUESTIONS?