2. Renmin Hospital, Wuhan University Ding Xuhong (丁续红)
Asthma
Renmin Hospital, Wuhan University
Ding Xuhong (丁续红)

3. DEFINITION
A clinical syndrome of unknown etiology characterized by three distinct components
(1) Recurrent episodes of airway obstruction that resolve spontaneously or as a result of treatment (clinical manifestation)

4. (2)An exaggerated bronchoconstrictor response to stimuli that have little or no effect in nonasthmatic subjects, a phenomenon known as airway hyperresponsiveness (Pathophysiologically) (3) Inflammation of the airways as defined by a variety of criteria (Pathogenesis)

5. PATHOLOGY Constriction of airway smooth muscle
Airway epithelium thickening
Mucus plugging

6. Lung Hyperinflation in Asthma

7. Thick bronchi with Mucous plugs

8. Mucous plug in asthma

9. Asthma - Microscopically
Patchy necrosis of epithelium
Sub-mucosal glandular hyperplasia
Hypertrophy of bronchial smooth muscle
Eosinophils, mast cells, lymphocytes (Th2) infiltration

12. Asthma Microscopic Pathology
Obstructed
Inflammed
Bronchi

13. PATHOGENESIS
OF ASTHMA

14. Asthma Pathogenetic Types
Extrinsic (Allergic/Immune)
Atopic - IgE
Occupational - IgG
Allergic Bronchopulmonary Aspergillosis - IgE
Intrinsic (Non-immune)
Aspirin induced
Infection induced

16. Risk Factors that Lead to Asthma Development
Predisposing Factors
Atopy
Causal Factors
Indoor Allergens
Domestic mites
Animal Allergens
Cockroach Allergens
Fungi
Outdoor Allergens
Pollens
Occupational Sensitizers
Contributing Factors
Respiratory infections
Small size at birth
Diet
Air pollution
Outdoor pollutants
Indoor pollutants
Smoking
Passive Smoking
Active Smoking

17. Airway
Hyperresponsiveness
Genetic
Inducers Allergens,Chemical sensitisers, Air pollutants, Virus infections
INFLAMMATION
Airflow Limitation
SYMPTOMS
Cough Wheeze
Dyspnoea
Triggers
Allergens, Exercise,
Cold Air, SO Particulates

18. DIAGNOSIS OF ASTHMA History and patterns of symptoms
Physical examination
Measurements of lung function

19. PATIENT HISTORY
Has the patient had an attack or recurrent episodes of wheezing?
Does the patient have a troublesome cough, worse particularly at night, or on awakening?
Does the patient cough after physical activity (e.g playing)?
Does the patient have breathing problems during a particular season (or change of season)?

20. Do the patient’s colds ‘go to the chest’ or take more than 10 days to resolve?
Does the patient use any medication (e.g. bronchodilator) when symptoms occur? Is there a response?
If the patient answers “YES” to any of the above questions, suspect asthma

21. Physical Examination Wheeze -Usually heard without a Remember -
stethoscope
Dyspnoea
Rhonchi heard with a stethoscope
Use of accessory muscles
Remember -
Absence of symptoms at the time of examination does not exclude the diagnosis of asthma

22. Blood Finding Blood eosinophilia, elevated serum level of sIgE
Arterial blood gases:
PaO2 between 55 and 70mmHg
PaCO2 between 25 and 35mmHg

23. Radiographic finding
In severe asthma, hyperinflation, pneumomediastinum or pneumothorax may be detected

24. ECG
Sinus tachycardia (usually), right axis deviation, right bundle branch block, “P pulmonale”, ST-T wave abnormalities (severe asthma)

25. Diagnostic testing
Diagnosis of asthma can be confirmed by demonstrating the presence of reversible and variable airway obstruction using Peak Flow Meter

26. Bronchial challenge test: PC20<8mg/mL
Reversibility test: FEV1 increase more than 12% after inhalation of salbutamol, the absolute value of increase >200ml
Variability of PEF diurnally ≥20%

27. Differential diagnosis
Chronic bronchitis
Heart failure (“cardiac asthma”)
Hypersensitivity pneumonia
Lung cancer

28. Goals to Be Achieved in Asthma Control
Achieve and maintain control of symptoms
Prevent asthma episodes or attacks
Minimal use of reliever medication
No emergency visits to doctors or hospitals
Maintain normal activity levels, including exercise
Maintain pulmonary function as close to normal as possible
Minimal (or no) adverse effects from medicine

29. Tool Kit for Achieving Management Goals
Relievers
Preventers
Peak flow meter
Patient education

30. What Are Relievers? (also known as rescue medication)
Bronchodilator (beta2 agonist)
Quick relief of symptoms (within 2-3 minutes)
Used during acute attacks
Action lasts 4-6 hrs
Not for regular use

31. Relievers Short acting 2 agonists Salbutamol (万托林) Anti-cholinergics
Ipratropium bromide（爱全乐）
Xanthines
Theophylline
Adrenaline injections

32. What are Preventers? Anti-inflammatory Takes time to act (1-3 hours)
Long-term effect (12-24 hours)
Only for regular use
(whether well or not well)

33. Prevent future attacks
Long term control of asthma
Prevent airway remodeling

34. Preventers Corticosteroids Anti-leukotrienes
Prednisolone, Betamethasone Montelukast, Zafirlukast
Beclomethasone, Budesonide
Fluticasone Xanthines
Theophylline SR
Long acting 2 agonists Mast cell stabilisers
Bambuterol, Salmeterol Sodium cromoglycate
Formoterol
COMBINATIONS
Salmeterol/Fluticasone
Formoterol/Budesonide

35. Patient Education in the Clinic
Explain nature of the disease (i.e. inflammation)
Explain action of prescribed drugs
Stress need for regular, long-term therapy
Allay fears and concerns
Peak flow reading
Treatment diary / booklet

36. Status Asthmatic
FEV1 < 40%pred with treatment, PaCO2 increases, developing major complication such as pneumothorax
Close monitoring
Frequent treatments with inhaled β2-agonists, intravenous aminophylline, high-dose intravenous steroid
Oxygen supplement
Antibiotics – if infection exist
If indicated, intubation of the trachea and
mechanical ventilation

37. The Pregnant Asthmatic
No departure from the ordinary management of asthma
No unnecessary medication should be administered
Systemic steroid should be used sparingly
Tetracycline, atropine, terbutaline(博利康尼?), iodine-containing mucolytics should be avoided

38. Key Messages Asthma is a common disorder
It produces recurrent attacks of cough with or without wheeze
Between attacks people with asthma lead normal lives as anyone else
In most cases there is some history of allergy in the family

39. Asthma can be effectively controlled, although it cannot be cured
Effective asthma management programs include education, objective measures of lung function, environmental control, and pharmacologic therapy
A stepwise approach to pharmacologic therapy is recommended. The aim is to accomplish the goals of therapy with the least possible medication

40. Thank you!