Asthma training. Mike Levin Division of Asthma and Allergy Red Cross Hospital

Transcription

1 Asthma training Mike Levin Division of Asthma and Allergy Red Cross Hospital

2 Introduction Physiology Diagnosis Severity Treatment Control Stage 3 of guidelines Acute asthma Drug delivery Conclusion Overview

3 Introduction Physiology Diagnosis Severity Treatment Control Stage 3 of guidelines Acute asthma Drug delivery Conclusion Overview

4 Asthma prevalence Asthma affects 20% of children Asthma is the commonest chronic disease in South African children. South Africa is ranked 25th worldwide in the prevalence of asthma South Africa is ranked fifth for asthma case fatality rates

5 Introduction Physiology Diagnosis Severity Treatment Control Stage 3 of guidelines Acute asthma Drug delivery Conclusion Overview

6 What is asthma? Asthma is a disorder of the airways caused by reversible inflammation that leads to the air passages contracting in response to a wide range of stimuli with enhanced irritability of the airways and increased mucus secretion

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8 Smooth muscle Spasm Swollen mucosa Secretions Set alight-ness Scarring

9 Allergic inflammation Inflammation is the most important aspect of asthma Inflammation causes the other features That s why asthma needs treatment with regular controller therapy given every day whether the patient is symptomatic or not to control the inflammation.

10 Introduction Physiology Diagnosis Severity Treatment Control Stage 3 of guidelines Acute asthma Drug delivery Conclusion Overview

11 How do we diagnose it?? recurrent wheeze and/or cough and/or dyspnoea responsive to bronchodilators

12 How do we diagnose it?? recurrent wheeze and/or cough and/or dyspnoea responsive to bronchodilators

13 Has the patient had recurrent wheezing? Do the patient s colds go to the chest or take >10 days to clear up? Does the patient have a cough at night? Are symptoms seasonal? Does the patient experience symptoms after exposure to allergens or pollutants? Does the patient wheeze or cough after exercise?

14 How do we diagnose it?? recurrent wheeze and/or cough and/or dyspnoea responsive to bronchodilators

15 Bronchodilator response Bedside test or < 5 Administer bronchodilator Reassess after 10 minutes Document respiratory rate respiratory distress auscultation Bronchodilator and diary card over 2 weeks Trial of oral corticosteroids for 7 14 days

16 Bronchodilator response Lung function tests 10 mins after bronchodilators > 5 yrs FEV1 increase by > 12 % (15 %) PEF increase by > 15 % (20%) Diurnal variability > 20 %

17 Exclude other conditions Respiratory infections worms foreign body lymph nodes cystic fibrosis Vocal cord dysfunction Cardiac pulmonary oedema myocarditis congenital abnormalities GIT G-O reflux disease Mimics other diseases. Asthma and atopy may coexist with other diseases.

18 Introduction Physiology Diagnosis Severity Treatment Control Stage 3 of guidelines Acute asthma Drug delivery Conclusion Overview

19 Select initial treatment according to severity Severity Days with Nights with PEFR / FEV1 (GINA Guide) symptoms symptoms 1) Mild intermittent 2) Mild persistent 3) Moderate persistent 4) Severe persistent < 2 / week < 2 / month > 80 % predicted < 20 % variability 3 6 / week 3 4 / month > 80 % predicted % variability daily > 5 / month % predicted > 30 % variability continual frequent < 60 % predicted > 30 % variability Assign patients to the most severe category in which any feature occurs.

20 Introduction Physiology Diagnosis Severity Treatment Control Stage 3 of guidelines Acute asthma Drug delivery Conclusion Overview

21 Step 1 Step 2 Step 3 Step 4 Step 5 No controller medication required Asthma education and environmental control As needed reliever medication e.g. rapid-acting β2-agonist

22 Education Goals of therapy Minimal or no chronic symptoms day or night Minimal or no exacerbations No limitation on activity; school or parent s work missed Minimal use of inhaled B2 agonists Minimal or no adverse effects from medication

23 Asthma medication Controllers (preventers) Inhaled steroid pumps Long acting B2 agonists Leukotriene receptor antagonists Theophylline Relievers SABA Ipratropium bromide

24 Step 1 Step 2 Step 3 Step 4 Step 5 Asthma education and environmental control As needed reliever medication e.g. rapid-acting β2-agonist No controller medication required Select one Low-dose inhaled steroid (ICS) Leukotriene modifier

25 Step 1 Step 2 Step 3 Step 4 Step 5 Asthma education and environmental control As needed reliever medication e.g. rapid-acting β2-agonist No controller medication required Select one Select one Low-dose inhaled steroid (ICS) Leukotriene modifier Medium-dose ICS Medium or Lowdose ICS plus long-acting β 2- agonist Low-dose ICS plus leukotriene modifier

26 Step 1 Step 2 Step 3 Step 4 Step 5 Asthma education and environmental control As needed reliever medication e.g. rapid-acting β2-agonist No controller medication required Select one Select one Select one Low-dose inhaled steroid (ICS) Leukotriene modifier Medium-dose ICS Medium or Lowdose ICS plus long-acting β 2- agonist Medium or highdose ICS plus long-acting β 2 - agonist Medium or highdose ICS plus Leukotriene modifier Low-dose ICS plus leukotriene modifier Medium or highdose ICS plus theophylline

27 Step 1 Step 2 Step 3 Step 4 Step 5 Asthma education and environmental control As needed reliever medication e.g. rapid-acting β2-agonist No controller medication required Select one Select one Select one add either Low-dose inhaled steroid (ICS) Medium-dose ICS Medium or highdose ICS plus long-acting β 2 - agonist Oral steroid (lowest dose) Leukotriene modifier Medium or Lowdose ICS plus long-acting β 2- agonist Medium or highdose ICS plus Leukotriene modifier Anti-IgE treatment Low-dose ICS plus leukotriene modifier Medium or highdose ICS plus theophylline

28 Introduction Physiology Diagnosis Severity Treatment Control Stage 3 of guidelines Acute asthma Drug delivery Conclusion Overview

29 Asthma Control Characteristic Assessing Daytime symptoms Limitation of activities Nocturnal symptoms/awakening Need for reliever/rescue medication Lung function (PEF or FEV 1 ) Monitoring Treating Follow up regularly. Assess and move up and down treatment algorithm according to control.

30 Asthma Control Characteristic Controlled (all of the following) Partly controlled (any measure present) Uncontrolled Daytime symptoms None (twice or less/week) Limitation of activities None Any Nocturnal symptoms/awakening None More than twice/week Any Three or more characteristics of partly controlled asthma Need for reliever/rescue medication Lung function (PEF or FEV 1 ) None (twice or less/week) Normal More than twice/week <80% predicted or personal best (if known)

31 Reasons for poor asthma control Incorrect diagnosis Individual variation in response to treatment Incorrect choice of inhaler and poor inhaler technique Smoking Patient belief and adherence Co-morbid rhinosinusitis

32 Before altering medication consider Is the diagnosis correct? Is there objective evidence of asthma? Other factors: Gastrooesophageal reflux, ABPA Is the patient adherent to their existing therapy? Does the patient have allergic rhinosinusitis? Treatment of this may improve asthma control Is the patient able to use their inhaler properly? Are there any correctable trigger factors, e.g. occupational sensitisers, does the patient smoke?

33 Step 1 Step 2 Step 3 Step 4 Step 5 No controller medication required Select one Select one Select one add either Low-dose inhaled steroid (ICS) Medium-dose ICS Medium or highdose ICS plus long-acting β 2 - agonist Oral steroid (lowest dose) Leukotriene modifier Medium or Lowdose ICS plus long-acting β 2- agonist Medium or highdose ICS plus Leukotriene modifier Anti-IgE treatment Low-dose ICS plus leukotriene modifier Medium or highdose ICS plus theophylline

34 Introduction Physiology Diagnosis Severity Treatment Control Stage 3 of guidelines Acute asthma Drug delivery Conclusion Overview

35 Controller medications Inhaled glucocorticoids (e.g. budesonide, fluticasone propionate) Leukotriene modifiers (e.g. montelukast, zileuton) Long-acting inhaled β 2 -agonists (LABA) (e.g. salmeterol, formoterol)

36 Controller medications Inhaled glucocorticoids (e.g. budesonide, fluticasone propionate) The most effective controller medication, delivering drugs directly to the airways Leukotriene modifiers (e.g. montelukast, zileuton) Long-acting inhaled β 2 -agonists (LABA) (e.g. salmeterol, formoterol)

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38 Inhaled corticosteroids Most asthmatics well controlled with low dose inhaled steroids. Side effects uncommon.

39 Steroid doses Low dose Medium High dose Budesonide (Budeflam, Pulmicort, Inflammide) Beclomethasone (Becotide, Beclate) Fluticasone (Flixotide) Document dose of MDIs accurately

40 Controller medications Inhaled glucocorticoids (e.g. budesonide, fluticasone propionate) The most effective controller medication, delivering drugs directly to the airways Leukotriene modifiers (e.g. montelukast, zileuton) Used as add on particularly in children < 5 Particularly appropriate for patients unwilling or unable to take ICS, or those that experience side effects with ICS Long-acting inhaled β 2 -agonists (LABA) (e.g. salmeterol, formoterol)

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42 Uses for LTRA s Monotherapy for mild asthma Monotherapy if patient noncompliant or steroid phobic Mild asthma with exercise induced component Aspirin sensitive asthma. Add on therapy for moderate persistent asthma Potential for steroid sparing effects Add on therapy for severe uncontrolled asthma.

43 Controller medications Inhaled glucocorticoids (e.g. budesonide, fluticasone propionate) The most effective controller medication, delivering drugs directly to the airways Leukotriene modifiers (e.g. montelukast, zileuton) Used as add on particularly in children < 5 Particularly appropriate for patients unwilling or unable to take ICS, or those that experience side effects with ICS Long-acting inhaled β 2 -agonists (LABA) (e.g. salmeterol, formoterol) Synergistic effects Not monotherapy Not below 5

44 Long acting B 2 agonists Anti-inflammatory action is synergistic with steroids. Reduce bronchial hyperresponsiveness and inhibit release of inflammatory mediators and prevent plasma exudation. 12 hour bronchodilation. Receptor desensitisation and downregulation. This effect prevented by concomitant steroid administration.

45 Uses for LABAs Improves outcomes when added to medium or high dose inhaled steroids. Not first line agents Use only as combination, never mono-therapy Use as steroid sparing agents or as step up before increasing steroids Contraindicated below age of 5

46 SMART therapy LABAs are formoterol and salmeterol Both have long duration of action Salmeterol has delayed onset of action Formoterol is rapid acting Symbicord maintenance and reliever therapy To blunt attacks

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49 Introduction Physiology Diagnosis Severity Treatment Control Stage 3 of guidelines Acute asthma Drug delivery Conclusion Overview

50 Drugs in acute asthma Adrenaline B2 receptors relaxation SABA s + relaxation Acetylcholine Cholinergic receptors spasm Anticholinergics - relaxation

51 Drugs in acute asthma Adrenaline B2 receptors relaxation SABA s + relaxation Acetylcholine Cholinergic receptors spasm Anticholinergics - relaxation

52 Acute exacerbations Oxygen therapy Monitor all patients Achieve O 2 saturation of 95%, >93% in children Inhaled rapid-acting β 2 -agonists MDI with spacer (unless hypoxic) Repeat (at least) 3 doses in first hour Oral glucocorticoids Early administration Oral

53 Acute asthma

54 Acute asthma

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56 Administration of B2 agonists MDI/spacer 6-10 puffs Each puff separately Repeat every 20 minutes Drug (approved name) Dose Route Other directions Salbutamol 6 or 10 puffs INHAL via Spacer 100 microgram MDI How frequently should I prescribe multidoses? Multidose of bronchodilator gives an equivalent effect as a nebuliser and therefore does not require to be given more frequently than you would give nebulised medication

57 Severe exacerbations The attack is severe Cyanosis, sats < 94, prev ICU, drowsy, confused, silent chest, tachycardia, pulsus paradoxus, impaired speech / feeding breathless at rest, and/or PEF is <60% of predicted or personal best The response to the initial bronchodilator treatment is not prompt and sustained for at least three hours There is no improvement within 2 to 6 hours after oral glucocorticoid treatment is initiated There is further deterioration

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60 Give adequate inhaled therapy before considering anything else

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62 Introduction Physiology Diagnosis Severity Treatment Control Stage 3 of guidelines Acute asthma Drug delivery Conclusion Overview

63 Using a MDI is not easy Effective deposition of aerosols requires Slow inspiratory flow Deep inhalation and breath hold Quiet, non-distressed breathing

64 Using a MDI is not easy Timing is critical Actuation 1 second before inhalation reduces inhaled mass by 90% Late actuation results in the lung being filled with medication-free air and aerosol merely reaching the dead space and being exhaled Delivery of medication via a MDI without a spacer is highly ineffective

65 Spacers Problems with spacers Spacer is less portable than MDI alone Multiple actuations into spacer Need comfortable but well sealed mask Inspiratory flow to open holding valve with tidal breathing

66 Issues with nebulisers Flow rate of 6-8 l/min Driven by O2 or air Dead volume of 0.5-1ml When a nebuliser starts sputtering delivery is minimal Filling volume of 4-5 ml

67 Introduction Physiology Diagnosis Severity Treatment Control Stage 3 of guidelines Acute asthma Drug delivery Conclusion Overview

68 Inhaler technique Prepare the device Check the orientation Actuate the device Shake the device if it is an MDI

69 Inhaler technique Prepare the device Check the orientation Actuate the device Shake the device if it is an MDI Prepare the body Breathe out fully away from the mouthpiece Consider differences between MDI and DPI devices

70 Inhaler technique Prepare the device Check the orientation Actuate the device Shake the device if it is an MDI Prepare the body Breathe out fully away from the mouthpiece Consider differences between MDI and DPI devices mouthpiece in mouth Ensure a good seal and make sure the teeth are not in front of the device

71 Inhaler technique Prepare the device Prepare the body mouthpiece in mouth DPI MDI Check the orientation Actuate the device Shake the device if it is an MDI Breathe out fully away from the mouthpiece Consider differences between MDI and DPI devices Ensure a good seal and make sure the teeth are not in front of the device Breathe as fast and as hard as possible from the beginning OR Start breathing slowly and actuate. Breathe in over 5 seconds and hold breath for 5 seconds

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