ASTHMA

1. ASTHMA

2. Definition • Reversible airflow obstruction + • Airway hyper-reactivity

3. Pathology • Inflammation involving eosinophils and T lymphocytes • Release of various mediators and cytokines • Initially reversible, spontaneously or with drugs • Eventually permanent structural change results in irreversibility = remodelling

4. Remodelling • Extent varies between patients • Lung function decline faster than in non asthmatics • Early intervention may prevent decline

5. Incidence • 20% of children have asthma • 6% of adults • 15% cases are late onset • Boys . Girls

6. Statistics • 5 million people in uk receive asthma treatment • NHS treatment costs £850 million/year • 18 million working days lost/year

7. Presentation • Symptoms • Cough • Expiratory wheeze • Chest tightness • Dyspnoea • Nocturnal cough • Exercise induced wheeze

8. Diagnosis • Twice daily PEF recording for 2 weeks • 15% variation = asthma • Therapeutic trial of salbutamol • >15% improvement in PEF after 15-30 mins = asthma • 2 week trial inhaled or oral steroid • 15% improvement in PEF = asthma

9. Differential diagnosis • Adults • Gastro oesophageal reflux • Bronchiectasis • COPD • LVF • PE • Interstial lung disease • Tumour

10. Differential diagnosis • Children • Cystic fibrosis • Ciliary dyskinesia • Foreign body inhalation • Gastro oesophageal reflux • Bronchiectasis

11. Diagnosis - Children • Can’t do PEFR • Daignosis made on history and response to treatment • 30% children wheeze in first 3 years of life

12. Differential diagnosis • COPD Spirometry fev1/fvc < 75% • LVF Older, echo lvedp <50% • PE • Vocal cord dysfunction • Psychogenic breathlessness

13. Triggers • Infections particularly viral • Allergens e.g. house dust mite, pollens, animals. • Occupations e.g. isocyanate containing paints, flour • Environmental pollutants e.g. cigarette smoke, sulphur dioxide

14. Triggers • Drugs e.g. beta blockers • Exercise • Cold air • Hyperventilation • Foods • Psychological factors

15. Management • Aims • Control of symptoms and exacerabtions • Minimal lifestyle disturbance • 40% of asthmatics say their symptoms affect their lifestyle

16. Management • BTS guidelines • Stepwise approach

17. Step one • Mild intermittent asthma • Short acting inhaled beta agoinst as required

18. Step two • Needing beta agonist every day • Regular preventer therapy • Add inhaled steroid 200-800micrograms/day • Start at dose appropriate to severity of disease • 400 micrograms for most people

19. Step 3 add on therapy • Add inhaled long acting beta agonist = LABA • i.e. salmeterol • oxis

20. Poor response • Stop LABA • Increase inhaled steroid to 800mcg/day

21. If still symptomatic • Consider slow release theophyline • Or • Leukotriene receptor antagonist

22. Step 4 • Increase inhaled steroids • Adults 2000mcg/day • Children 800mcg/day • Add in 4 th drug • LTRA • SRT • Oral beta agonist

23. Step 5 • Oral steroids in lowest possible dose • Maintain high dose inhaled steroids • Refer to respiratory specialist

24. Short acting beta 2 agonists • Relievers • Salbutamol and terbutaline • Use on prn basis • Useful before exercise

25. Short acting beta 2 agonists • Overuse • Tachycardia • Tremor • hypokalaemia

26. Inhaled corticosteroids • Preventers • Improves symptoms and lung function • Might prevent permanent airway damage

27. Inhaled corticosteroids • Beclomethasone, fluticasone and equally effective • Fluticasone twice as potent needs half the dose • Thrush and dysphonia decreased by rinsing mouth out after use abd using a spacer

28. Inhaled corticosteroids • High doses associated with • Cataract formation • Adrenal suppression • Slow growth rate in children – no evidence that final height is affected

29. Adrenal suppression • Presentation • Fatigue • Weigth loss • Anorexia nausea • Abdo pain • Hypoglycaemia • seizures

30. LABA • Salmeterol and eformeterol • Patients > 5 years • Relieves symptoms and improves lung function • Adding ALBA to inhaled steroids is more effective than doubling the dose of steroid

31. LTRA • Montelukast and zafirlukast • Block action of leukotrienes • Montelukast – add on therapy age 2 years and older • Zafirlukast – monotherapy or add on therapy age 12 years and older

32. LTRA • Reduce exacerbations • 5-8% improvement lung function less than inhaled steroids or LABA • 4 week trial continue if symptoms and lung function improve

33. LTRA • Side effects • GIT upset • Headache • Rash • Churg strauss syndrome

34. Theophylline • Phyllocontin continuus • Has anti inflammatory actions • Use at step 3 • Side effects • GIT • Arrythmias • Hypokalaemia • convulsions

35. Oral steroids • Should be under specilaist review • Monitor • BP • Blood sugar • Osteoporosis prevention

36. Delivery systems • MDI 10% dose reaches lungs • MDI + spacer • Breath actuated inhaler • Dry powder inhaler • Turbohaler • Accuhaler • Clickhaler

37. Children • 0-2 yrs mdi + spacer mask • 2-5 yrs mdi + spacer • > 5 yrs mdi + spacer, breath actuated inhaler or dry powder inhaler

38. Lifestyle measures • Avoid precipitating factors • Housedust mite • Vacuuming • Impermable matress covers • Reduced soft furnishings

39. Lifestyle measures • No smoking infamily • Keep pets out of bedrooms • Keep weight down

40. Acute asthma • Signs of severity • Children • Inability to feed • Use of accessory muscles • Sub costal recession • Nasal flaring

41. Acute asthma • Signs of severity • Adults • Pulse > 110 bpm • Resp rate > 25/min • PEF 33-50% max • Inability to complete sentenes

42. Life threatening • Cyanosis • Silent chest • Bradycardia • Hypotension • Poor resp effort • PEF < 33% max

43. Management • Oxygen • Nebulised beta 2 agonist • Salbutamol 5mg • Atrovent 500mcg • Halve doses for children

44. Management • Short course oral steroids • Adults 40mg/day • Children > 5 30mg/day 3 days • Children 2-5 20mg/day 3 days • Children < 2 10mg/day 3 days