Asthma GINA guideline for pediatric patient

Diagnosis Criteria for Asthma

Asthma Control Test (ACT) Scores

Asthma Management for Pediatrics (Ages 5 years - 14 years)

This comprehensive guide delves into the complexities of asthma management for pediatric patients, drawing from the most recent GINA 2023 recommendations and incorporating relevant Thai guidelines. We'll cover essential concepts, practical considerations, and specific management strategies, all tailored for pediatric residents.

Understanding Asthma

Asthma is a chronic respiratory condition characterized by reversible airway obstruction, airway inflammation, and hyperreactivity. It typically presents with symptoms like wheezing, coughing, shortness of breath, and chest tightness, which vary in frequency and intensity. Asthma exacerbations or attacks can be triggered by various factors such as allergens, exercise, cold air, and respiratory infections. The underlying pathophysiology involves inflammation leading to bronchoconstriction, increased mucus production, and reduced airflow.

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Criteria for Diagnosis

Asthma can affect individuals of all ages, but it is most commonly diagnosed in children aged 6 months to 5 years. The diagnostic criteria involve a combination of clinical evaluation, patient history, and objective tests.

Characteristic Symptoms

Asthma in children is often suggested by the presence of characteristic respiratory symptoms. These include:

• Wheezing: A high-pitched whistling sound, particularly on exhalation.
• Shortness of Breath
• Chest Tightness
• Coughing: Especially at night or early morning.

Spirometry Test

The primary diagnostic test for asthma is spirometry, which measures the airflow into and out of the lungs. Key spirometry measurements include:

• Forced Expiratory Volume in One Second (FEV1): Measures the amount of air a person can forcefully exhale in one second. In asthma, an increase or decrease in FEV1 of greater than 12% and 200 mL from the baseline after administering a bronchodilator is indicative of asthma.
• Forced Vital Capacity (FVC): The total amount of air exhaled during the spirometry test.
• Bronchodilator Response: A significant increase in lung function after inhaling a bronchodilator medication (like albuterol). Specifically, an increase in FEV1 of more than 12% and 200 mL from baseline is suggestive of asthma.

Peak Expiratory Flow (PEF)

Measuring peak expiratory flow assesses the maximum speed of expiration. A variability in peak flow readings (difference between morning and evening readings) of at least 20% over a week can indicate asthma.

Additional Tests (if needed)

• Methacholine Challenge Test: Used if initial spirometry tests are normal. Methacholine causes airway narrowing, and if the FEV1 drops by 20% or more, it indicates asthma.
• Fractional Exhaled Nitric Oxide (FeNO) Testing: Elevated levels can indicate airway inflammation, common in asthma.
• Allergy Testing: Since allergies can trigger asthma, allergy testing may be conducted to identify specific triggers.
• Response to Asthma Medication: A trial of asthma medication can be part of the diagnostic process, especially if other tests are inconclusive. Improvement with medication supports the diagnosis.
• Exclusion of Alternative Diagnoses: Conditions like COPD, heart failure, and vocal cord dysfunction can mimic asthma. It's essential to rule these out.
• Patient History and Physical Examination: A detailed patient history, including family history of asthma and allergies, and physical examination are crucial components of the diagnosis.

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Asthma Control Test (C-ACT) for Children Ages 4–11

The Childhood Asthma Control Test (C-ACT) is specifically designed for children ages 4–11 to assess their asthma control over the past four weeks.

Structure

The C-ACT consists of 7 questions. The child with asthma answers four questions regarding:

1. How their asthma is today.
2. Their symptoms when they’re physically active.
3. How often they cough due to asthma.
4. How often asthma disrupts their sleep.

Their parent or guardian then answers three questions addressing the number of days in the past month the child:

1. Had daytime symptoms.
2. Wheezed.
3. Woke up during the night.

Interpreting the Score

• The final score ranges from 0 to 27.
• A score of 20–27 indicates well-controlled asthma.
• A score of 13–19 indicates not well-controlled asthma.
• A score of 0–12 indicates very poorly controlled asthma.

Clinical Significance

Regular use of the C-ACT helps in monitoring asthma over time and aids in identifying patients who need a step-up in their asthma therapy. It provides a quantifiable measure to evaluate the effectiveness of current asthma management strategies.

Pathophysiology

• Airway Inflammation: Inflammation of the airways leads to swelling and redness within the bronchial walls, contributing to airway narrowing and mucus production.
• Airway Hyperresponsiveness (AHR): This is an exaggerated response of the airways to various stimuli, such as allergens, cold air, exercise, or irritants, leading to bronchoconstriction.
• Airway Obstruction: During an asthma attack, the muscles surrounding the airways constrict, the lining of the airways swells, and the airways produce extra mucus, leading to difficulty in breathing.
• Airway Remodeling: Over time, chronic inflammation can lead to structural changes in the airway walls, such as fibrosis, increased smooth muscle mass, and angiogenesis, which can contribute to the persistence of asthma symptoms and decreased responsiveness to treatment.

Diagnosis Overview

• Symptoms: Wheezing, shortness of breath, chest tightness, cough (often at night/morning).
• Spirometry Tests:
  • FEV1: Changes >12% and >200 mL post-bronchodilator suggest asthma.
  • FVC: Total air exhaled.
  • PEF: Variability >20% over a week indicates asthma.
• Additional Tests:
  • Methacholine Challenge: FEV1 drop >20% indicates asthma.
  • FeNO Testing: Elevated levels show airway inflammation.
  • Allergy Testing: Identifies triggers.
  • Response to Medication: Improvement with asthma drugs aids diagnosis.
• Exclusion of Other Diagnoses: Ruling out conditions like COPD.
• Patient History and Physical Exam: Critical for a comprehensive diagnosis.

Asthma diagnosis involves assessing symptoms, spirometry results, response to medication, and patient history. Additional tests are used if needed. Diagnosis may require multiple tests to confirm the presence of variable airflow obstruction and reversibility.

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Management

GINA 2023: Two Tracks to Achieve Control

Track 1: Symptom Driven (PREFERRED)

• This approach prioritizes symptom relief and prevention of severe exacerbations.
• It utilizes a single inhaler containing both ICS (inhaled corticosteroid) and formoterol (LABA - long-acting beta-agonist) for both maintenance and as-needed relief.
• Advantages: Simplicity, convenient single inhaler, proven efficacy in reducing severe exacerbations.

Track 2: Proactive Regular Dosing (Alternative)

• Places a stronger emphasis on proactively controlling underlying airway inflammation.
• Utilizes regular ICS as the foundation of therapy.
• Patients use a separate SABA (short-acting beta-agonist) inhaler for quick relief of symptoms. Alternatively, an as-needed low-dose ICS/formoterol inhaler can be used.
• Advantages: May provide more consistent control of inflammation over time.

Stepwise Asthma Management: Tailoring Treatment to Control

Intermittent Asthma (C-ACT Score 25–27)

• Definitive Treatment: Low-dose ICS as needed for symptoms.
  • Example: Budesonide 200 mcg 1 puff as needed.
• Alternative: As-needed low-dose ICS-formoterol.

Mild Persistent Asthma (C-ACT Score 20–24)

• Definitive Treatment: Daily low-dose ICS.
  • Example: Budesonide 200 mcg 1 puff twice daily.
• Consider adding: LAMA (long-acting muscarinic antagonist) or low-dose ICS/formoterol as needed for symptoms if control is not achieved.

Moderate Persistent Asthma (C-ACT Score 13–19)

• Definitive Treatment: Daily low-dose ICS/LABA.
  • Example: Budesonide/formoterol 160/4.5 mcg 1 puff twice daily.
• Consider adding: LAMA, leukotriene receptor antagonist (LTRA), or increasing the ICS-formoterol dose if control remains inadequate.

Severe Persistent Asthma (C-ACT Score 0–12)

• Definitive Treatment: Daily high-dose ICS/LABA.
  • Example: Fluticasone/salmeterol 500/50 mcg 1 puff twice daily.
• Additional options:
  • LAMA: Tiotropium bromide 2.5 mcg 1 puff once daily.
  • Biologic therapy: For patients with severe, allergic asthma uncontrolled on high-dose ICS/LABA. Omalizumab is one example.
  • Oral corticosteroids: Short courses may be necessary for exacerbations.

Monitoring, Adjusting, and Educating: The Cornerstones of Success

• Regular Monitoring:
  • Use the Childhood Asthma Control Test (C-ACT) to regularly assess symptom control.
  • Regularly monitor lung function with spirometry (FEV1/FVC).
  • Assess adherence to therapy and inhaler technique at each visit.
• Adjusting Treatment:
  • Adjust treatment based on symptom control, risk factors,lung function, and patient response.
• Patient Education:
  • Empower parents and children to actively manage asthma through education about:
    • Their medications, inhaler technique, and potential side effects.
    • Identifying and avoiding asthma triggers.
    • Having a written asthma action plan for managing exacerbations.

Key Principles of Treatment

• Symptom Control: Essential for immediate relief, but managing underlying inflammation is crucial to prevent long-term complications.
• Inflammation Suppression: Key to preventing airway remodeling and exacerbations.
• Individualized Treatment: Tailor asthma management to each child's needs, considering symptom severity, risk factors, medication response, and preferences.

Medication Options

• Inhaled Corticosteroids (ICS): The cornerstone of asthma treatment, effectively reducing airway inflammation. Common examples include Budesonide and Fluticasone.
• Long-Acting Beta-Agonists (LABA): Relax airway muscles for long-lasting relief. Examples include Formoterol and Salmeterol.
• Short-Acting Beta-Agonists (SABA): Provide rapid symptom relief during acute episodes. Salbutamol (Ventolin) is a commonly used SABA.
• Leukotriene Antagonists (LTRA): Block inflammatory mediators, offered as an alternative or add-on therapy. Montelukast is a widely used LTRA.

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Case Studies

Case Study 1

• Patient: A 6-year-old with well-controlled asthma on Salmeterol/Fluticasone (50/250) 1 puff BID for several years.
• Event: Acute asthmatic attack with acute bronchitis after a respiratory infection.
• Management: Hospitalization, treatment with systemic corticosteroids, bronchodilators, and antibiotics.
• Key Points: Even well-controlled asthma patients can experience exacerbations triggered by infections. Prompt and aggressive treatment of exacerbations is crucial to prevent complications.

Case Study 2

• Patient: An 8-year-old diagnosed with asthma 3 years prior, experiencing uncontrolled symptoms.
• Current Medication: Budesonide (200 µg) 1 puff BID, Montelukast (10 mg) 1 tab PO HS.
• Management Considerations: Assess medication efficacy and adherence. Consider stepping up treatment using either Track 1 (increasing ICS-formoterol) or Track 2 (adding a LAMA or biologic agents).
• Key Points: Individualized assessment and treatment adjustment are critical for optimal asthma control.

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Important Considerations from Research

• Regular ICS/LABA vs. as-needed ICS/LABA: Regular use shows better asthma control, reduced exacerbations, and less airway inflammation.
• Regular ICS plus SABA vs. as-needed ICS/LABA: Regular ICS with as-needed SABA demonstrates superior asthma control in mild asthma.
• ICS/Formoterol vs. Other ICS/LABA: Fluticasone propionate/Formoterol may offer similar efficacy at lower doses with potentially fewer side effects due to formoterol's higher β2 selectivity.

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Conclusion

Successfully managing pediatric asthma requires a patient-centered approach that considers:

• Individualized Assessment: Evaluating symptom control, risk factors, lung function, and patient preferences.
• Choice of Treatment Track: Selecting between Track 1 (ICS-formoterol-based) and Track 2 (regular ICS-based) based on patient-specific factors.
• Regular Monitoring and Adjustment: Asthma is a dynamic disease, requiring ongoing assessment and treatment adjustments to achieve and maintain control.

By staying updated on the latest GINA and national guidelines, and by applying these principles in clinical practice, pediatric residents can provide optimal care for their asthma patients.