COPD/ Asthma. Dr Heather Lewis Honorary Clinical Lecturer

Transcription

1 COPD/ Asthma Dr Heather Lewis Honorary Clinical Lecturer

2 Objectives To understand the pathogenesis of asthma/ COPD To recognise the clinical features of asthma/ COPD To know how to diagnose asthma/ COPD To be able to assess the severity of asthma/ COPD To be able to explain the management of asthma/copd

3 Asthma Definition: Variable airflow obstruction With symptoms wheeze, breathlessness, chest tightness, cough Airway hyperresponsiveness Airway inflammation

4 Asthma Pathogenesis 4 step process: Airway inflammation Airway obstruction - Smooth muscle contraction Bronchial hyper-responsiveness Airway remodelling

5 Risk factors Male gender Airway hyperesponsiveness Neonatal lung function Family history of asthma Atopy Endotoxin exposure Occupational exposure nursing and cleaning Smoking active and passive Obesity? Maternal age? Paracetamol?

6 Clinical features of asthma Symptoms that are: Frequent and recurrent Occur at night and in the early morning Triggers damp, cold, pets, perfumes, emotions, laughter, aspirin, Beta-blockers Not just associated with colds History of atopy Family history of atopy Widespread wheeze on auscultation Improvement in spirometry/ symptoms with therapy

7 Diagnosis - children High clinical probability: Trial of treatment Low probability: More detailed investigation and specialist referral Intermediate probability: Watchful waiting and review Trial of treatment and review Spirometry Significant (>12%) increase in FEV1 from baseline after bronchodilators supports asthma diagnosis

8 Diagnosis - adults Careful history and examination, and evidence of airflow obstruction that varies over a short period of time Spirometry FEV1/FVC < 0.7 Obstructive picture FVC decreased, but FEV1/FVC normal restrictive picture Other tests that may be helpful: Skin prick allergen testing Blood eosinophilia >4% Raised specific IgE to dog, cat or mite

9 Spirometry Forced Vital Capacity The maximum volume of air that can be forcibly exhaled following a maximal inspiration Forced Expiratory Volume (FEV1) Maximal volume of air expelled in one second from full inspiration Forced Expiratory Ratio (FER) (FEV1/ FVC) x100 Percentage of FVC expelled in the first second of forced expiration

10 Differential diagnosis of asthma Without airway obstruction: Chronic cough syndromes Hyperventilation syndrome Vocal cord dysfunction Rhinitis GORD Heart failure Pulmonary fibrosis

11 Differential Diagnosis of asthma With airway obstruction: COPD Bronchiectasis Inhaled foreign body Obliterative bronchiolitis Large airway stenosis Lung cancer Sarcoidosis

12 Asthma management non pharmacological Avoidance of smoking Subcutaneous immunotherapy Weight reduction

13 Pharmacological treatment: Step 1: Short acting beta-agonist Step 2: Add inhaled steroid ( mcg/day) Step 3: Add in long acting beta-agonist If still not adequately controlled Inc inhaled steroid dose to 800mcg/day Consider leukotriene antagonist, or theophylline Step 4: Consider inc inhaled steroid to 2000mcg/day Addition of 4 th drug eg leukotriene receptor antagonist, theophylline, B1 agonist tablet Step 5 Oral steroids

14 Assessment of asthma severity Classification: Moderate Acute Severe Life threatening Near fatal Brittle

15 Assessment of asthma severity Moderate asthma: PEFR >50-75% of best Increasing symptoms No features of acute severe asthma Acute severe asthma: Any one of: PEF 33-55% of best RR >25/ min HR >110/min Inability to complete sentences in one breath

16 Life threatening Asthma Signs: Altered conscious level Silent chest Exhaustion Arrhythmias Hypotension Cyanosis Poor respiratory effort Measurements: PEFR <33% Sp02 < 92% PaO2 < 8kPa Normal PaCO2

17 Asthma severity Near fatal asthma: Raised PaCO2 and/or Requiring mechanical ventilation with raised inflation pressures Brittle asthma: Type 1: Wide PEFR variability (>40% diurnal variation, for over 50% of the time over >150 days) Type 2: Sudden severe attacks on a background of previously well controlled asthma

18 Treatment of acute severe asthma High flow oxygen via non-rebreathe mask Beta-agonist therapy salbutamol nebs Ipratropium bromide nebulisers Steroids IV or oral Magnesium IV aminophylline IV fluids Timely referral to ICU and intubation if features of life-threatening or near fatal asthma present at any time or not responding to therapy

19 COPD

20 COPD - definition Airflow obstruction Progressive Not fully reversible Reduced FEV (<80%) Reduced FEV1/FVC (<0.7) Predominantly caused by smoking

21 Symptoms Exertional breathlessness Chronic cough Regular sputum production Frequent winter bronchitis Wheeze.

22 Chronic bronchitis Chronic productive cough for three months in each of two successive years in a patient in whom other causes of chronic cough have been excluded

23 Emphysema Abnormal and permanent enlargement of the airspaces distal to the terminal bronchioles. This is accompanied by destruction of the airspace walls, without obvious fibrosis Centrilobular Dilatation and destruction of respiratory bronchioles Panlobular Destruction of whole acinus

24 Pathogenesis Bronchial gland hypertrophy Goblet cell metaplasia Squamous metaplasia Loss of cilia and ciliary dysfunction Increased smooth muscle and connective tissue Accumulation of CD8 lymphocytes and neutrophils Fibrosis and increased deposition of collagen in the airway walls

25 Diagnosis Classic symptoms Spirometry CXR FBC BMI May require: High resolution CT thorax ECG alpha-1 antitrypsin Echocardiogram Sputum culture

26 Assessment: MRC dyspnoea Scale 1. Not troubled by breathlessness except on strenuous exercise 2. Short of breath when hurrying or walking up a slight hill 3. Walks slower than contemporaries on level ground because of breathlessness, or has to stop for breath when walking at own pace 4. Stops for breath after walking about 100 m or after a few minutes on level ground 5. Too breathless to leave the house, or breathless when dressing or undressing

27 Stage: Assessment: GOLD classification COPD Characteristics: Mild : Moderate Severe : FEV1 > 80 % predicted FEV1 <50% (<80% predicted) FEV1 <30% ( <50% predicted) Very Severe COPD FEV1 <30 percent predicted or FEV1 <50 percent predicted plus chronic respiratory failure

28 Non-pharmacological management Smoking cessation Pulmonary rehabilitation MRC grade 3 and above MDT approach Vaccinations: Seasonal influenza Pneumococcal vaccination Thoracic surgery: FEV1 < 50% Single large bullae Refer for consideration of bullectomy

29 Pharmacological management Inhaled bronchodilators Short acting initially stepping up to; Long acting Anticholinergic Tiotropium Inhaled corticosteroids FEV1 <50% predicted Two or more exacerbations in 12 month period Theophylline Nebulisers Mucolytic therapy

30 Management Long Term Oxygen therapy (LTOT): PaO2 < 7.3kPa when stable Or Pa02 of 7.3 8kPa when stable plus one of Secondary polycythaemia Nocturnal hypoxaemia Peripheral oedema Pulmonary hypertension Need LTOT for at least 15 hours/day for benefit

31 Management Home Non Invasive Ventilation (NIV): Hypercapnic resp failure, where patients have required invasive ventilation or Patients who are hypercapnic or acidotic on LTOT Cor pulmonale Manage with diuretics Do not use ACEi, B-blockers, calcium channel blockers, digoxin

32 Management of Acute exacerbation of COPD Antibiotics Nebulised bronchodilators Nebulised ipratropium bromide IV theophylline Controlled oxygen therapy Physiotherapy NIV Intubation

33 Prognosis Worse prognostic factors: Low FEV1 Low BMI Continued smoking Decreased exercise capacity Male gender Formally assessed by BODE index

34 BODE index Variable FEV1 > <35 Distance walked in 6 minutes (m) MRC dyspnoea scale > BMI >21 <21 <149

35 Predicted 4 year Survival BODE score reflects a patients percentage chance of surviving 4 years BODE score Percentage 4 year survival % % % %

36 ANY QUESTIONS?