Asthma
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Asthma

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  • COPD is often a mixture of conditions that have airflow obstruction as the common element. It is not unusual for a patient to present with three diagnoses – emphysema, chronic bronchitis and asthma, all of which have an element of poorly reversible airflow obstruction: such an individual would be classed as having COPD. Conversely, a patient may have simple emphysema or simple bronchitis with no airflow obstruction, and these individuals would not be classed as having COPD. Most cases of asthma have completely reversible airflow obstruction and on this basis can be differentially diagnosed from COPD. 1.2.5
  • There are several other risk factors that play a role in COPD development but they are all minor compared with cigarette smoking. Occupational job exposure to hazardous airborne substances can increase the risk of COPD, especially in individuals who already smoke. Air pollution may cause respiratory symptoms but is unlikely to cause lung function deficiency. Hyperresponsive airways may play a role in the development of COPD and are not necessarily the result of allergy or atopy. The role of viral infections of the respiratory tract in the development of COPD are not clearly established. However, once COPD is established any respiratory infection will accelerate lung function decline. Less than 1% of COPD is thought to be due to AAT deficiency. 1.4.6
  • In more advanced disease, the patient may show other characteristic signs of the illness. Cyanosis (bluish discolouration of skin and mucous membranes) may be present at rest or during mild exercise. An enlarged liver and distension of the veins in the neck are suggestive of cor pulmonale or heart failure. Anorexia and weight loss are not unusual and there may be evidence of an abnormal decrease in the amount of oxygen in the blood – hypoxaemia, and/or an abnormal increase in the amount of carbon dioxide in the blood – hypercapnia. Patients with end-stage disease typically adopt postures that relieve dyspnoea such as leaning forward while standing or sitting with their arms positioned forward on their knees. Exhalation often occurs through pursed lips which prevents collapse of the airways and provides some alleviation of discomfort. 2.1.2
  • The main diagnostic measures of COPD are agreed by all guideline documents and include: history taking, symptomatic assessment, physical examination and spirometric measurements of lung function. 3.0.3
  • The GOLD guidelines recommend that spirometry should be performed if any of the key indicators (chronic cough, sputum production, dyspnoea, patient history of exposure to risk factors) are present. These indicators are not diagnostic on their own but the presence of several of them increases the probability of a diagnosis of COPD. Spirometry is considered to be essential for establishing a diagnosis of COPD. The GOLD guidelines recommend that the most sensitive test is the FEV 1 /FVC ratio. A post-bronchodilator FEV 1 of  80% of the predicted value in combination with an FEV 1 /FVC of <70% is thought to confirm the diagnosis of COPD. 3.0.6
  • The GOLD guidelines classify disease severity into 4 stages: ‘At risk’ (0), ‘Mild COPD’ (I), ‘Moderate COPD’ (II) and ‘Severe COPD’ (III). The staging of COPD is based on airflow limitation as measured by spirometry, which is essential for diagnosis and provides a useful description of the severity of pathological changes in COPD. 3.0.7
  • Deaths in the developed world ~ 45,000 [death rate ~ 5 per 100,000 patients]
  • In mild COPD the chest X-ray may be normal. As the disease advances, hyperinflation of the chest is evident as larger lung volume, a low flat diaphragm, a thin heart shadow, a marginally increased heart size and an enlarged retrosternal air space on the lateral view. 2.1.3
  • Two spirometric measurements are the most frequently used: FEV 1 and FVC, although IVC or IC (inspiratory capacity) is thought to be increasingly important. PEF can be measured using both a spirometer and peak flow meter. Measurement of FEV 1 , PEF and FVC alone is not enough to diagnose early-stage COPD. 2.2.1
  • The spirometer can measure several different lung capacities that make up the total lung capacity. Usually the patient is asked to undergo a ‘forced’ measurement against time – FEV 1 is the most typically used and this measures the maximum forced expiration in one second. The tidal volume shows the volume of air in the lungs during ‘tidal breathing’ – the usual shallow breathing during rest. 2.2.2
  • FEV 1 is generally the most useful test to assess severity and progression of COPD, although the ratio between FEV 1 and FVC is the most sensitive measure of early airflow obstruction as it is always below the usual adult value of approximately 80%. FEV 1 reduces as the disease progresses. FEF can also be used and reflects small airway function. It is markedly reduced in patients with COPD but has greater variability than FEV 1 and so is not valuable for routine monitoring. PEF can give a crude estimate of lung function. It is not useful for diagnosing COPD since PEF can be relatively well preserved in the early stages of disease. IVC (IC) is becoming an important lung function measurement in the assessment of COPD because patients tend to have more problems during inspiration than during expiration. 2.2.3

Asthma Asthma Presentation Transcript

  • Lecture 2
  • Learning objectives – 1
    • To understand that COPD is:
      • a disease state of airflow limitation that is not fully reversible
      • a chronic inflammatory condition
      • often caused by chronic bronchitis, emphysema or a mixture of both
      • pathologically different from asthma
      • usually the result of cigarette smoking or occupational exposure to small particles or dusts
      • increasing in prevalence, particularly in women
      • the cause of significant direct and indirect costs
  • Learning objectives – 2
    • To understand that COPD is:
      • associated with symptoms such as chronic cough, chronic mucus production and breathlessness
      • diagnosed by assessment of clinical signs and symptoms together with spirometric measurements of airflow obstruction
    • To understand the importance of spirometry and the use of flow-volume loops in the diagnosis of COPD
    • To understand current guidelines for the diagnosis and staging of COPD (GOLD)
    View slide
  • Learning objectives – 3
    • To understand current guidelines for the treatment of COPD (GOLD)
    • To understand the unique position of Foradil ® Aerolizer™ in the treatment of COPD
    View slide
  • The common component of COPD is airflow obstruction Chronic bronchitis Emphysema Airflow obstruction Asthma
  • Summary of risk factors for the development of COPD
    • Smoking and passive smoking
    • Occupational factors
    • Genetic factors, e.g. AAT deficiency
    • Air pollution
    • Atopy and hyperresponsive airways
    • Infections
  • Clinical features of advanced COPD
    • Cyanosis
    • Distention of veins in neck
    • Liver enlargement
    • Cor pulmonale
    • Anorexia and weight loss
    • Hypoxaemia
    • Hypercapnia
  • Diagnostic measures recommended by major Thoracic Societies
    • Clinical and smoking history
    • Symptoms (especially dyspnoea, cough, sputum and wheezing)
    • Physical examination
    • Pre- and post-bronchodilator spirometry
    • Chest radiography (to exclude other diseases)
    ATS. Am J Respir Crit Care Med 1995 ERS. Eur Respir J 1995 BTS. Thorax 1997 Pauwels RA, et al. Am J Respir Crit Care Med 2001
  • GOLD guidelines outline key points in COPD diagnosis Chronic cough Present intermittently or every day Often present throughout the day; seldom only nocturnal Chronic sputum production Any pattern of chronic sputum production may indicate COPD Dyspnoea that is: Progressive (worsens over time) Persistent (present every day) Described by the patient as an ‘increased effort to breathe’, or ‘gasping’ Worse during exercise Worse during respiratory infections History of exposure to risk factors, especially: Tobacco smoke Occupational dusts and chemicals Smoke from home cooking and heating fuels Pauwels RA, et al. Am J Respir Crit Care Med 2001
  • GOLD guidelines: Classification of severity of COPD Stage Characteristics 0: At risk - Normal spirometry - Chronic symptoms (cough, sputum production) I: Mild COPD - FEV 1 /FVC <70% - FEV 1  80% predicted - With or without chronic symptoms (cough, sputum production) II: Moderate COPD - FEV 1 /FVC <70% - 30%  FEV 1 <80% predicted (IIA: 50%  FEV 1 <80% predicted, IIB: 30%  FEV 1 <50% predicted) - With or without chronic symptoms (cough, sputum production, dyspnoea) III: Severe COPD - FEV 1 /FVC <70% - FEV 1 <30% predicted or FEV 1 <50% predicted plus respiratory failure or clinical signs of right heart failure
  • What Is Asthma?
    • Asthma is a chronic disease that affects the airways, which causes breathing problems. It can be life threatening.
    • The inside walls of the airways are inflamed (swollen). The inflammation makes the airways very sensitive, and they tend to react strongly to allergens or irritants.
    • When the airways react, they get narrower and less air flows through to the lung tissues. This causes symptoms like wheezing (a whistling sound when you breathe), coughing, chest tightness, and trouble breathing. Breathing problems are called attacks or episodes of asthma.
  • Epidemiology
    • About 150 million people around the world suffer from asthma.
    • Most common chronic illness of childhood: 10% of children and 5% of adults) / Prevalence is approximately 6% (3% in Japan).
    • More boys than girls, but in adulthood, more women than men.
    • Age: <15 (12.4 % ), 15-44 (37.9%), 45-64 (25.7%), >65 (23.0%)
    • (At primary hospital, 46% of patients are < 15 years old).
    • Annual death of c.a. 180,000
    • Annual incidence: 0.2%
    • Ethnic difference: African-American twice
    • higher than Caucasian. No info related to
    • Asian versus Caucasian
  • Increase in Asthma Prevalence with Time 1982 1988 1992 1968 1982 1979 1984 1989 1975 1973 1971-74 1976-80 Source: Global Initiative for Asthma NHLBI/WHO Workshop Report 1996 *Diagnosed asthma: asthma diagnosed at any time. Asthma and/or wheeze.
  • Market Size CAGR: € + 14.7% USD + 6.2% SU - 0.2% annual growth rate % + 9.3 + 8.5 + 17.6 + 24.3 Asthma Worldwide: Value 1996 - 2000
  • Clinical Signs and Symptoms
    • Common asthma symptoms are:
    • Coughing. Coughing from asthma is often worse at night or early in the morning, making it hard to sleep.
    • Wheezing. Wheezing is a whistling or squeaky sound when you breathe.
    • Chest tightness. This can feel like something is squeezing or sitting on the chest.
    • Shortness of breath. Some people say they can't catch their breath, or they feel breathless or out of breath. You may feel like you can't get enough air in or out of your lungs.
    • Faster breathing or noisy breathing.
  • Pathophysiology
    • Etiology is unknown as of today. However, the factors listed below may worsen asthma:
    • Allergens
    • Animal dander (from the skin, hair, or feathers of animals)
    • Dust mites (contained in house dust)
    • Cockroaches
    • Pollen from trees and grass
    • Mould (indoor and outdoor)
    • Irritants
    • Cigarette smoke
    • Air pollution
    • Cold air or changes in weather
    • Strong odors from painting or cooking
    • Scented products
    • Strong emotional expression (including crying or laughing hard), and stress
    • Others
    • Medications such as aspirin and beta-blockers
    • Sulfites in food (dried fruit) or beverages (wine)
    • A condition called gastroesophageal reflux disease (GERD) that causes heartburn and can worsen asthma symptoms, especially at night.
    • Irritants or allergens that you may be exposed to at your work such as special chemicals or dusts
    • Infections.
  • Ethnic Differences
    • Extrinsic factors: the incidence and prevalence of asthma vary from country to country and region to region. The exact reasons behind such differences are unknown but are presumed to be due to the differences in external factors (socioeconomic, types of environmental allergens, dietary, etc.)
    • Intrinsic factors: no clear racial predisposition has been identified although some genetic linkages have been demonstrated.
    • (Need assessment in disease prevalence, medical practice, drug metabolism, availability of medical technologies, laboratory test ordering practicing, drug prescribing practice, healthcare financing policy must be considered. )
  • Diagnosis and Classification
    • MEDICAL HISTORY
    • PHYSICAL EXAMINATION
    • Hyper-expansion of the thorax,
    • Sounds of wheezing during normal breathing, or a prolonged phase of forced exhalation
    • Increased nasal secretion, mucosal swelling, and nasal polyps.
    • Atopic dermatitis/eczema or any other manifestation of an allergic skin condition.
    • PULMONARY FUNCTION TESTING (SPIROMETRY)
    • Spirometry measurements (FEV1, FVC, FEV1/FVC).
    • ( 肺活量計 )
  • Standard of Care
    • National Institutes of Health National Asthma Education and Prevention Program divides the medication into two:
      • Quick Relief medicines give rapid, short-term treatment and are taken when you have worsening asthma symptoms that can lead to asthma episodes or attacks. You will feel the effects of these medicines within minutes. An example is a short-acting inhaled bronchodilator.
      • Long-term Control medicines are taken every day, usually over long periods of time, to control chronic symptoms and to prevent asthma episodes or attacks. You will feel the full effects of these medicines after taking them for a few weeks. People with persistent asthma need long-term control medicines. Examples are inhaled corticosteroids, long-acting beta agonists, leukotriene modifier, theophyline, Cromolyn, nedocromil
  • GINA Stepwise Treatment Guidelines for Adults Cromolyn Theophylline Inhaled CS low/high dose Short-act  2 Long-act  2 Mild Intermittent Mild Persistent Moderate Persistent Severe Persistent GINA: Global Initiative for Asthma, CS: Corticosteroids, LTA: Leukotriene antagonist LTA Reliever Controller Oral CS
    • Definition of Exacerbations
    • Genentech
    • Decrease in AM PEFR > 20% on 3 of 7 days prior to visit
    • Decrease in FEV 1 > 20%
    • Urgent or unscheduled visit for asthma symptoms
    • Increase in ß-agonist use of >50 % for at least 2 consecutive days
    • Abbott
    • Increase in inhaler use by > 33% of the number of occasions of use
    • Decrease in FEV 1 > 20%
    • Decrease in AM PEFR > 25% from previous
    • Merck
    • Decrease in PM PEFR > 20 %
    • AM PEFR < 180 L/min
    • Increase in ß-agonist use < 70 % (or at least 2 puffs)
    • Increase in baseline symptom score > 50 %
    • Awake all night
    • Asthma attack resulting in an unscheduled visit, ER or hospital,
    • treatment with oral steroids
  • Death Rates Are Increasing, Especially in North America
    • Two landmark surveys in USA (1998; 2,509 patients, 512 doctors, 101 nurses, 113 pharmacists) and Europe (1999; 2,803 patients) sponsored by GW
      • 9 % of asthma patients hospitalized overnight for asthma in the past year in the US (7% in EU)
      • 23% of asthma patients ER visit in the past year in the US (10% in EU)
      • 49% of children and 25% of adult patients missed school or work in the past 12 months in the US (25% in EU)
      • 30% of asthma patients awoke with breathing problems at least once a week during the past four weeks in the US (30% in EU)
    Guidelines vs. Reality
  • Chest X-rays do not have a pivotal role in diagnosis of COPD Hyperinflated lungs severe COPD Normal X-ray mild COPD
  • Measurements of lung function
    • PEF peak expiratory flow
    • FEV 1 forced expiratory volume in one second
    • FVC forced vital capacity
    • IVC inspiratory vital capacity
    • FEF* forced expiratory flow
    *Also known as maximum expiratory flow (MEF)
  • Subdivisions of the total capacity of the lungs Total lung capacity Full inspiration Full expiration Tidal volume Residual volume Maximum forced inspiration Maximum forced expiration FVC
  • Lung function tests are pivotal for assessment of COPD severity
    • FEV 1 reduced
    • FVC normal/reduced (depending on severity)
    • FEV 1 /FVC reduced
    • FEF reduced
    • PEF reduced
    • IVC reduced