Respiratory Medicine: Asthma and COPD

1. Respiratory Medicine:Asthma and COPD Dr Rickbir Singh Randhawa FY1

2. Definition: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

3. Definition: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.

4. AetiologyAsthma • 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)

5. Aetiology/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 α1-antitrypsin deficiency (<1%) consider in non smokers or in younger patients

6. HistoryAsthma • Intermittent wheeze • Breathlessness (dyspnoea) • Cough (often nocturnal) • Occasionally sputum • Diurnal variation in symptoms/ peak flow- morning dips of peak flow recordings

7. HistoryAsthma: 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 !

8. HistoryAsthma: things to also ask! • Precipitating factors if present • Compliance with medication • Reliever usage (inhaler) – gauge severity • Occupational Hx-cause • Sleep- interference? Severity • Smoking Hx • Eczema/hayfever- atopy • Days off school/work – gauge severity • Remember CROSSED mnemonic!

9. HistoryCOPD • Chronic breathlessness • Chronic Cough/sputum production • Wheeze • Smoker! • Minimal diurnal variation in symptoms compared to asthma • Age of onset >35 years (Rare cause is α1-antitrypsin deficiency (<1%) consider in non smokers or in younger patients)

10. Clinical signs O/E Asthma COPD • Tachypnoea • Use of accessory muscles of respiration • Hyper inflated chest (reduced chest expansion) • Hyper resonant percussion note • Reduced air entry • Polyphonic 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

11. Severity 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

12. Severity 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 kPa) • PaO2 <8kPa/O2 sats <92% • Low pH <7.35 acidosis (CO2 retention)

13. Severity of COPD

14. InvestigationsAsthma • 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

15. InvestigationsAsthma • 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

16. InvestigationsCOPD • 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)

17. InvestigationsCOPD • 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 • α1-antitrypsin levels- in young patients or with minimal smoking Hx

18. Obstructive vs Restrictive defectSpirometry/PFT

19. ManagementAcute life threatening Asthma • Start Rx before Ix ABCDE! • Oxygen 15L NRB- sit patient up, 02 sats 94-98%/intubate • Salbutamol- 5mg Nebulised, back to back Nebs • Hydrocortisone 100mg IV • Ipratropium bromide 0.5mg nebulised • Theophylline (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

20. Management Chronic AsthmaChronic Asthma

21. Chronic 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

22. Management 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

23. Management 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

24. Chronic Management COPD

25. Chronic 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

26. Inhalers-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)

27. Inhaler: 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.

28. Clinical 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

29. Questions • 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)?

30. THANK YOU FOR LISTENING ANY QUESTIONS?