بسم الله الرّحمن الرّحیم

1. بسم الله الرّحمن الرّحیم

2. Pediatric asthma Adel Ahadi, MD

3. Asthma is a chronic inflammatory condition of the lung airways resulting in episodic airflow obstruction • ETIOLOGY. • Although the cause of childhood asthma has not been determined, contemporary research implicates a combination of • environmental exposures • inherent biological • genetic vulnerabilities →More than 22 loci on 15 autosomal chromosomes • Respiratory exposures in this causal environment include • inhaled allergens • respiratory viral infections • chemical • biological air pollutants such as environmental tobacco smoke

5. EPIDEMIOLOGY. • Asthma is a common chronic disease, causing considerable morbidity→in 2002, • 8.9 million children (12.2%) had been diagnosed with asthma in their lifetime • 4.2 million children (5.8%) had an asthma attack in the preceding 12 mo, indicative of current disease • Boys (14% vs 10% girls) • children in poor families (16% vs 10% not poor) • childhood asthma is the most common cause of • childhood emergency department visits • Hospitalizations • missed school days • A disparity in asthma outcomes links high rates of asthma hospitalization and death with • poverty, ethnic minorities, and urban living

6. Approximately 80% of all asthmatics report disease onset prior to 6 yr of age. • Of all young children who experience recurrent wheezing→only a minority will go on to have persistent asthma in later childhood.

7. Early Childhood Risk Factors for Persistent Asthma • Parental asthma • Allergy   • Atopic dermatitis   • Allergic rhinitis   • Food allergy   • Inhalant allergen sensitization   • Food allergen sensitization • Severe lower respiratory tract infection   • Pneumonia   • Bronchiolitis requiring hospitalization • Wheezing apart from colds • Male gender • Low birthweight

8. Asthma Predictive Index for Children • MAJOR CRITERIA • Parent asthma • Inhalant allergen sensitization • Eczema • MINOR CRITERIA • Allergic rhinitis • Wheezing apart from colds • Eosinophils ≥ 4%   • Food allergen sensitization

9. Types of Childhood Asthma. • Asthma is considered to be a common clinical presentation of intermittent, recurrent wheezing and/or coughing • There are 2 main types of childhood asthma: • (1) recurrent wheezing in early childhood, primarily triggered by common viral infections of the respiratory tract • (2) chronic asthma associated with allergy that persists into later childhood and often adulthood. • A 3rd type of childhood asthma typically emerges in females who develop obesity and early-onset puberty (by 11 yr of age) • Triad asthma, characteristically associated with • hyperplastic sinusitis • nasal polyposis • hypersensitivity to aspirin and non-steroidal anti-inflammatory medications (ibuprofen • The most common persistent form of childhood asthma is that associated with allergy

10. PATHOGENESIS as well as airways edema basement membrane thickening subepithelial collagen deposition smooth muscle mucous gland hypertrophy, and mucus hypersecretion —all processes that contribute to airflow obstruction

11. Asthma Triggers • Common viral infections of the respiratory tract • Aeroallergens in sensitized asthmatics • Animal dander   • Indoor allergens   •  Dust mites    • Cockroaches    • Molds •  Seasonal aeroallergens    • Pollens (trees, grasses, weeds)   • Seasonal molds   • Environmental tobacco smoke   • Air pollutants    • Ozone   •  Sulfur dioxide    • Particulate matter •  Dust   • Strong or noxious odors or fumes • hairsprays   • Cleaning agents • Occupational exposures   • Farm and barn exposures   • Formaldehydes, cedar, paint fumes • Cold air, dry air • Exercise • Crying, laughter, hyperventilation Co-morbid conditions   • Rhinitis   • Sinusitis   • Gastroesophageal reflux

12. CLINICAL MANIFESTATIONS AND DIAGNOSIS. • the most common chronic symptoms are of asthma • expiratory wheezing • Intermittent dry coughing • nonfocal chest “pain • Older children and adults will report associated • shortness of breath • chest tightness • Respiratory symptoms can be worse at night • Daytime symptoms→physical activities or play • asthma symptoms in children can be subtle and nonspecific, including • self-imposed limitation of physical activities • general fatigue (possibly due to sleep disturbance) • difficulty keeping up with peers in physical activities

13. The presence of risk factors, such as • a history of other allergic conditions • allergic rhinitis • allergic conjunctivitis • atopic dermatitis • food allergies • parental asthma • symptoms apart from colds, supports the diagnosis of asthma. • The chest examination is often normal. • Deeper breaths • In clinic, quick resolution (within 10 min) • Decreased breath sounds in some of the lung fields, commonly the right lower posterior lobe→regional hypoventilation • Crackles (or rales) and rhonchi • The combination of segmental crackles and poor breath→ atelectasis

14. Differential Diagnosis of Childhood Asthma • UPPER RESPIRATORY TRACT CONDITIONS • Allergic rhinitis • Chronic rhinitis • Sinusitis • Adenoidal or tonsillar hypertrophy Nasal foreign body • MIDDLE RESPIRATORY TRACT CONDITIONS • Laryngotracheobronchitis (e.g., pertussis) • Laryngeal web, cyst, or stenosis • Vocal cord dysfunction • Tracheoesophageal fistula • Vascular ring • Foreign body aspiration • LOWER RESPIRATORY TRACT CONDITIONS • Bronchopulmonary dysplasia (chronic lung disease of preterm infants) • Viral bronchiolitis • Gastroesophageal reflux • Causes of bronchiectasis→Cystic fibrosis  Immune deficiency

15. In early life, chronic coughing and wheezing can indicate • recurrent aspiration • Tracheobronchomalacia • a congenital anatomic abnormality of the airways • foreign body aspiration • cystic fibrosis • bronchopulmonary dysplasia • In older children and adolescents, • vocal cord dysfunction (VCD) can present as intermittent daytime wheezing • the vocal cords close inappropriately, during inspiration and sometimes exhalation • producing shortness of breath • Coughing • throat tightness • often audible laryngeal wheezing and/or stridor • spirometric lung function • Speech therapy is the treatment of choice for VCD.

16. LABORATORY FINDINGS. • Lung function tests can help to confirm the diagnosis of asthma and determine disease severity. • Pulmonary Function Testing • Forced expiratory airflow measures are helpful • in diagnosing • monitoring asthma • in assessing efficacy of therapy • Spirometry is helpful as an objective measure of airflow limitation • usually feasible in children >6 yr of age • on 3 attempts, the FEV1 (forced expiratory volume in 1 sec) is within 5%, then the highest FEV1 effort of the 3 is used

18. Lung Function Abnormalities in Asthma • Spirometry (in clinic)   • Airflow limitation    • Low FEV1 (relative to percentage of predicted norms)   • FEV1/FVC ratio <0.80   • Bronchodilator response (to inhaled β-agonist)    • Improvement in FEV1 ≥12% or ≥200 mL • Exercise challenge→aerobic exertion or running for 6–8 min   • Worsening in FEV1 ≥15% • Daily peak flow or FEV 1 monitoring: day to day and/or AM-to-PM variation ≥20%

19. Radiology. • Chest radiographs (posteroanterior and lateral views) in children with asthma often appear to be normal, • aside from subtle and nonspecific findings of hyperinflation • peribronchial thickening • Chest radiographs can be helpful in identifying • abnormalities that are hallmarks of asthma masqueraders • aspiration pneumonitis • hyperlucent lung fields in bronchiolitis obliterans • complications during asthma exacerbations • Atelectasis • Pneumomediastinum • Pneumothorax

20. A 4-year-old boy with asthma. Frontal (A) and lateral (B) radiographs show pulmonary hyperinflation and minimal peribronchial thickening. No asthmatic complication is apparent.

21. The Goals of Asthma Therapy: (Asthma Control) • Reducing impairment • prevent chronic and troublesome symptoms • require infrequent use (≤ 2 days a week) of inhaled SABA for symptoms • maintain (near) “normal” pulmonary function • maintain normal activity levels • meet patients’ and families’ satisfaction with care • Reducing risk • prevent recurrent exacerbations of asthma . • prevent progressive loss of lung function • provide optimal pharmacotherapy

22. The 4 Components of Asthma Management • Component 1: Measures of Asthma Assessment and Monitoring • Component 2: Education for a Partnership in Asthma Care • Component 3: Control of Environmental Factors and Comorbid Conditions That Affect Asthma • Component 4: Medications

23. Component 1: REGULAR ASSESSMENT AND MONITORING    • Asthma checkups      • Every 2–4 wk until good control is achieved      • 2–4 per yr to maintain good control    • Lung function monitoring • PEF monitoring is feasible in children as young as 4 yr old • The green zone (80–100% of personal best) indicates good control • the yellow zone (50–80%) indicates less than optimal control • the red zone (<50%) indicates poor control • Component 2: Control of Environmental Factors and Comorbid Conditions That Affect Asthma • Eliminate or reduce problematic environmental exposures    • Treat co-morbid conditions: • rhinitisdetected in ≈90% • sinusitis nasal saline irrigations , intranasal corticosteroids, 2–3 wk course of antibiotics • gastroesophageal reflux incidence of up to 64%8 to 12 wk • Annual influenza vaccination (unless egg-allergic)

25. Component 3:ASTHMA PHARMACOTHERAPY    • Long-term-control vs quick-relief medications    • Classification of asthma severity for anti-inflammatory pharmacotherapy    • is based on the following parameters: • (1) frequency of daytime • (2) nighttime symptoms • (3) degree of airflow obstruction by spirometry • (4) PEF variability • Step-up, step-down approach    • Asthma exacerbation management • Component 4: PATIENT EDUCATION    • Provide a two-part care plan      • Daily management      • Action plan for asthma exacerbations

26. Classification of Asthma Severity

27. Step 4 Severe persistent       • Symptoms/Night  →continual / frequent  • Preferred treatment       • High-dose inhaled corticosteroids • Long-acting inhaled β2-agonists    • Step 3 Moderate persistent •    Symptoms/Night  → daily / > 1night per Wk    • Preferred treatment    —    • Low-dose inhaled corticosteroids+long-acting inhaled β2- agonists • Medium-dose inhaled corticosteroids.    • Alternative treatment    —    • Low-dose inhaled corticosteroids + • either leukotriene receptor antagonist or theophylline

28. Step 2 Mild persistent   • Symptoms/Night  → > 2per Wk < 1 x daily / > 2night per mo • Preferred treatment      • Low-dose inhaled corticosteroid (with nebulizer or MDI with holding chamber with or without face mask or DPI) • Alternative treatment      • Cromolyn (nebulizer is preferred or MDI with holding chamber)    • leukotriene receptor antagonist. • Step 1 Mild intermittent Quick Relief All Patients    • Symptoms/Night  → ≤ 2 days per Wk /≤ 2 nights / mo • No daily medication needed.

29. Spacer devices decrease the coordination required to use MDIs, especially in young children; improve the delivery of inhaled drug to the lower airways minimize the risk of propellant-mediated adverse effects (thrush).

31. INHALED CORTICOSTEROIDS (ICS). • daily ICS therapy as the treatment of choice for all patients with persistent asthma • reduce asthma symptoms • improve lung function • reduce AHR • reduce “rescue” medication use • most important, reduce • urgent care visits • Hospitalizations • prednisone use for asthma exacerbations by about 50%

32. Asthma control

33. Asthma Exacerbation Management (Status Asthmaticus) • RISK ASSESSMENT ON ADMISSION   • Focused history    • Onset of current exacerbation → during sleep (between midnight ,8 am) • Frequency and severity of daytime and nighttime symptoms and activity limitation • Frequency of rescue bronchodilator use   • Current medications and allergies     • Potential triggers      • History of systemic steroid courses, emergency department visits, hospitalization, intubation, or life-threatening episodes • Clinical assessment • Physical examination findings: vital signs, breathlessness, air movement, use of accessory muscles, retractions, anxiety level, alteration in mental status   • Pulse oximetry     • Lung function (defer in patients with moderate • Risk factors for asthma morbidity and death

34. Risk Factors for Asthma Morbidity and Mortality • BIOLOGIC    • Previous severe asthma exacerbation    • Severe airflow obstruction    • History of rapidly occurring attacks    • Severe airways hyperresponsiveness (AHR)    • Increasing and large diurnal variation in peak flows    • Decreased chemosensitivity and perception of dyspnea    • Poor response to systemic corticosteroid therapy    • Male gender    • Low birthweight    • Nonwhite (especially black) ethnicity • ENVIRONMENTAL    • Allergen exposure    • Environmental tobacco smoke exposure    • Air pollution exposure    • Urban environment

35. ECONOMIC AND PSYCHOSOCIAL    • Poverty    • Crowding    • Mother <20 yr old    • Mother with less than high school education    • Inadequate medical care      • Inaccessible      • Unaffordable      • No regular medical care (only emergent)      • No care sought for chronic asthma symptoms      • Delay in care of asthma exacerbations    • Inadequate hospital care for asthma exacerbation    • Psychopathology in the parent or child    • Family problems    • Alcohol or substance abuse

36. Home Management of Asthma Exacerbations. • A written home action plan can reduce the risk of asthma death by 70%. • immediate treatment with “rescue” medication (inhaled SABA, up to 3 treatments in 1 hr). • A good response is characterized by • resolution of symptoms within 1 hr, • no further symptoms over the next 4 hr, • improvement in PEF to at least 80% of personal best. • The child's physician should be contacted for follow-up • If bronchodilators are required repeatedly over the next 24–48 hr. • If the child has an incomplete response to initial treatment with rescue medication • a short course of oral corticosteroid therapy (prednisone 1–2 mg/kg/day [not to exceed 60 mg/day] for 4 days)

37. Emergency Department Management of Asthma Exacerbations. • the primary goals of asthma management include • correction of hypoxemia • rapid improvement of airflow obstruction • prevention of progression or recurrence of symptoms. • Indications of a severe exacerbation include • breathlessness, dyspnea, retractions, accessory muscle use • tachypnea or labored breathing cyanosis • mental status changes • a silent chest with poor air exchange • severe airflow limitation (PEF or FEV1 <50% ) • Initial treatment includes • supplemental oxygen • inhaled β-agonist every 20 min for 1 hr • if necessary, systemic corticosteroids given either orally or intravenously • Inhaled ipratropium • An intramuscular injection of epinephrine

38. The patient may be discharged to home • if there is sustained improvement in symptoms • normal physical findings • PEF >70% of predicted or personal best • an oxygen saturation >92% on room air for 4 hr • Discharge medications include administration of • an inhaled β-agonist up to every 3–4 hr plus • a 3–7 day course of an oral corticosteroid

39. Management of Asthma During Surgery. • Patients with asthma are at risk from disease-related complications from surgery such as • bronchoconstriction • asthma exacerbation • Atelectasis • impaired coughing • respiratory infection • latex exposure • A systemic corticosteroid course may be indicated for patients • who are having symptoms • FEV1 or PEF <80% of the patient's personal best • who have received more than 2 wk of systemic corticosteroid • moderate-to-high dose ICS therapy →intraoperative adrenal insufficiency.

40. PROGNOSIS. • Recurrent coughing and wheezing occurs in 35% of pre–school-age children. • Of these, ⅓ continue to have persistent asthma into later childhood, while ⅔ improve on their own through the preteen years. • Asthma severity by the ages of 7–10 yr of age • Children with moderate to severe asthma and with lower lung function measures