Power point presentation on Asthma in both adults and children
- 2. TABLE OF CONTENT ● Definition ● Prevalence ● Risk factors ● Pathophysiology ● Signs and Symptoms ● Diagnosis in children and adults ● Management ● Acute Asthma Exacerbations
- 3. DEFINITION Asthma is defined by a history of respiratory symptoms such as wheeze, shortness of breath, chest tightness and cough that vary over time and in intensity, together with variable expiratory airflow limitation. Key components airway inflammation in all people with asthma. symptoms such as wheezing, breathlessness, chest tightness and cough that vary in time and intensity. Variable expiratory airflow limitation
- 4. PREVALENCE It is estimated that about 7.5% of the Kenyan population, or nearly 4 million people, have asthma. The prevalence of asthma in children between the ages of 12-14 years, was documented to have increased over a 5-year period. It is unclear if this trend has continued. Asthma has been observed to be more prevalent in urban as opposed to rural areas, however, it is currently unclear if this difference persists.
- 6. CAUSES Family history of asthma Bronchiolitis in childhood Exposure to tobacco smoke, particularly if the mother smokes during pregnancy Premature birth and Low birth weight Occupational exposure to plastics, agricultural substances and volatile chemicals Obesity Asthma is more common in prepubertal boys, but boys are more likely to grow out of their asthma during adolescence than girls
- 7. RISK FACTORS Both atopy and airway hyper- responsiveness (AHR) may be genetically determined A high salt diet and a diet that is low in antioxidant vitamins such as vitamin C or calorie intake may be associated with the development of asthma.
- 8. PATHOPHYSIOLOGY Asthma is usually mediated by immunoglobulin E (IgE) and precipitated by an allergic response to an allergen. IgE is formed in response to exposure to allergens such as pollen. Sensitisation occurs at first exposure, which produces allergen-specific IgE antibodies that attach to the surface of mast cells. Upon subsequent exposure, the allergen binds to the allergen-specific IgE antibodies present on the surface of mast cells, causing the release of inflammatory mediators such as leukotrienes, histamine and prostaglandins.
- 9. cont... These inflammatory mediators cause bronchospasm, triggering an asthma attack. If an attack is left untreated, eosinophils, T-helper cells and mast cells migrate into the airways. Excess mucus production caused by goblet cells plug the airway and, together with increased airway tone and airway hyperresponsiveness, this causes the airway to narrow and further exacerbates symptoms.
- 10. SUMMARY
- 11. CLINICAL FEATURES Possible triggers include: the common cold; allergens (e.g.pollen); exercise; exposure to hot or cold air; medicines (e.g. NSAIDs); and emotions such as anger, anxiety The classic signs of asthma are wheezing (especially expiratory wheezing) breathlessness coughing (typically in the early morning or at night time) chest tightness.
- 12. In severe obstruction of the airway, wheeze may be absent and the chest may be silent on auscultation (listening to the chest). In such cases, other signs such as cyanosis and drowsiness may be present, and the patient may be unable to complete full sentences. Severe exacerbations of asthma are medical emergencies. NOTE
- 13. DIAGNOSIS Diagnosis of asthma is based on medical history, physical examination, lung function testing and response to medication Children and adults with a high probability of asthma on assessment usually start a treatment trial, where their response is assessed using spirometry. A treatment trial in adults involves a patient being prescribed a six-to-eight week trial of inhaled beclometasone 200µg (or equivalent) twice a day, or two weeks of oral prednisolone 30mg daily. An improvement in FEV1 of 400ml or more following the trial is strongly suggestive of an underlying diagnosis of asthma. Those with an intermediate probability of asthma usually have lung function tests conducted, such as spirometry, peak flow and airway responsiveness.
- 14. Spirometry can be used to measure lung function and is a good guide to diagnosing asthma in adults. It is not always definitive; normal findings do not exclude a diagnosis of asthma . The spirometric measures used in the diagnosis of asthma are: Forced vital capacity (FVC) — the total volume of air expelled by a forced exhalation after a maximal inhalation Forced expiratory volume in one second (FEV1) — the volume of air expelled in the first second of a forced exhalation after maximal inhalation FEV1/FVC ratio An FEV1/FVC ratio below 0.75 is suggestive of airway obstruction in adults and below 0.9 in children Peak expiratory flow using a peak flow meter measures the resistance of the airway.
- 15. Assessment of airway responsiveness using inhaled mannitol or methacholine for patients with normal or near normal spirometry who have a baseline FEV1 of less than 70% . Both drugs induce bronchospasm. A fall in FEV1 of more than 15% following a test with mannitol is a specific indicator for asthma. Sputum eosinophils and exhaled nitric oxide concentration . A raised sputum eosinophil count (>2%) is seen in around 70–80% of patients with uncontrolled asthma. However, patients with COPD or chronic cough may also exhibit abnormal levels of eosinophils and the test should not be used for definite diagnosis. An exhaled nitric oxide level of more than 25 parts per billion supports a diagnosis of asthma.
- 17. DIAGNOSIS ALGORITHM FEV1: forced expiratory volume in 1 second; FVC: functional vital capacity; PC20: provocative concentration causing a 20% decline in FEV1; PD20: provocation dose causing a 20% decline in FEV1; PFT: pulmonary function testing.
- 18. Imaging should be restricted to those patients who have atypical symptoms or positive airway findings with severe or difficult to control symptoms . Chest imaging may reveal features of hyperinflation, bronchitis, chest infections, pneumothorax/mediastinum, cardiac disease, effusions, bronchiectasis and adenopathy.
- 19. Nonpharmacologic Management Breathing exercises Increased physical activity Incorporation of a healthy diet Avoidance of exposure to smoke and other triggers Counseling on proper inhaler technique
- 21. National Guidelines for Treatment Medications used in asthma can be classified into 3 main groups: 1. Controller medications These include inhaled steroid medications (ICS) which reduce airway inflammation and help control symptoms Examples include beclomethasone, budesonide, fluticasone and ciclosenide. Inhaled corticosteroids are often combined with long-acting beta 2 agonists (LABA), which are bronchodilators, to achieve and sustain asthma control. Available LABAs in Kenya include salmeterol, formoterol and vilanterol. .
- 22. 2. Reliever medications: Are also called rescue medications and work primarily as airway openers (bronchodilators) . Inhaled bronchodilators commonly used in Kenya include: • the rapid onset but short acting beta 2 agonist (SABA) salbutamol • the rapid and short acting muscarinic antagonist (SAMA) ipratropium bromide. 3. Add-on medications: Are used in addition to ICS, usually with a LABA, to control asthma in persons with persistent symptoms and/or exacerbations. They include the : • long-acting muscarinic antagonist (LAMA) tiotropium • leukotriene receptor antagonists (LTRA)- zileuton, montelukast, pranlukast and zafirlukast • oral steroids and biologic agents. Biologic agents include omalizumab, mepolizumab , resilizumab, and benralizumab
- 24. DOSAGES
- 26. ICS DOSES
- 27. Pharmacological treatment pathway for children under 5 1. Offer a SABA as reliever therapy to children under 5 with suspected asthma for symptom relief. 2. Consider an 8-week trial of a paediatric moderate dose of an ICS when asthma-related symptoms occur 3 times a week or more, or causing waking at night) orsuspected asthma that is uncontrolled with a SABA alone. 3. After 8 weeks, stop ICS treatment and continue to monitor the child’s symptoms however, if symptoms resolved then reoccurred within 4 weeks of stopping ICS treatment, restart the ICS at a paediatric low dose as first-line maintenance therapy. 4. If suspected asthma is uncontrolled ,consider an LTRA in addition to the ICS. 5. Refer the child to a healthcare professional with expertise in asthma if the asthma is still uncontrolled
- 28. Step 1 • Patient has infequent wheeze • SABA every 4–6 hours until symptoms disappear Step 2 • Three or more wheezing episodes per year or presence of other asthma symptoms • use of daily low dose ICS for at least 3 months and inhaled SABA if needed Step 3 • Good inhaler technique and non pharmacologic strategies, step up should be done • Doubling the low dose ICS or addition of an LTRA to the low dose ICS
- 29. Step 1 Infrequent asthma symptoms Controller:Low dose ICS whenever SABA is taken Reliever: Inhaled SABA Step 2 Controller: Daily low dose ICS and inhaled SABA. Reliever: Inhaled SABA Step 3 Controller: low dose ICS plus LABA or medium dose ICS or Low dose ICS+LTRA Reliever: Inhaled SABA Refer to specialists 6 - 11 years
- 30. Children Presenting with Acute Exacerbation of Asthma
- 31. Children above 12 and Adults For adults and children aged 12 years and above an anti-inflammatory agent must be included, preferably an inhaled corticosteroid to target airway inflammation. Use of SABAs as the sole therapeutic strategy has been shown to be ineffective, dangerous and may lead to worsening of asthma .
- 32. INHALERS Types of inhaler devices: Pressurized Metered Dose Inhalers (pMDIs) - A pMDI delivers asthma medicine through a small, handheld aerosol canister. Breath Actuated MDIs. Dry Powder Inhalers- require respiratory effort in order to use them. Soft Mist Inhalers. Nebulizers or wet aerosols General Guidance for use of Inhalers • Without spacer (for most children >12 years and adults) • With spacer (for most children <12 years and some adult patients,
- 33. 4.Place mouthpiece in mouth and press inhaler canister to release a dose of medication. Ask the patient to breathe (using a suction like action) in slowly, deeply and strongly 5. Hold breaths for at least ten seconds or as long as comfortable
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