What is the presentation and management of asthma?

Presentation of Asthma

Clinical Presentation

Asthma presents with recurrent episodes of wheezing, shortness of breath, chest tightness, and cough—symptoms that are characteristically worse at night and result from chronic airway inflammation causing hyperresponsive airways that narrow easily in response to various stimuli. 1

Cardinal Symptoms

• Wheezing: High-pitched whistling sounds during breathing, particularly on expiration 1, 2
• Dyspnea: Shortness of breath that varies in intensity and timing 1, 3
• Chest tightness: Sensation of constriction or pressure in the chest 1
• Cough: May be the only manifestation in cough-variant asthma, especially in young children 1
• Nocturnal symptoms: Symptoms frequently worsen at night, disrupting sleep 1

Pathophysiological Features

The underlying pathology involves chronic inflammation even in patients with mild symptoms, characterized by inflammatory cells (mast cells, eosinophils, T-lymphocytes), plasma exudation, edema, smooth muscle hypertrophy, mucus plugging, and epithelial shedding 1, 4, 3. This inflammation leads to airway hyperresponsiveness and variable airflow obstruction that is usually reversible, though chronic inflammation may cause irreversible changes 1, 2.

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Assessment and Diagnosis

Initial Evaluation

Use spirometry in all patients ≥5 years of age to confirm airflow obstruction that is at least partially reversible—this objective measurement is essential because symptoms alone can be misleading. 1

Key Diagnostic Measures

• Spirometry: Demonstrates airflow obstruction with improvement after bronchodilator (≥12% and 200 mL increase in FEV1) 1
• Peak expiratory flow (PEF): Useful for monitoring but less reliable than spirometry for diagnosis 1
• Symptom assessment: Frequency of daytime symptoms, nighttime awakenings, activity limitation, and rescue inhaler use 1

Severity Classification (Treatment-Naïve Patients)

Assess both impairment (current symptoms and functional limitations) and risk (likelihood of exacerbations or lung function decline) 1:

• Intermittent: Symptoms ≤2 days/week, nighttime awakenings ≤2×/month, FEV1 ≥80% predicted 1
• Mild persistent: Symptoms >2 days/week but not daily, nighttime awakenings 3-4×/month 1
• Moderate persistent: Daily symptoms, nighttime awakenings >1×/week, FEV1 60-80% predicted 1
• Severe persistent: Symptoms throughout the day, nighttime awakenings often 7×/week, FEV1 <60% predicted 1

Diagnostic Pitfalls

• Cough-variant asthma: Cough may be the only symptom; diagnosis confirmed by response to asthma medications 1
• Vocal cord dysfunction: Can mimic asthma; look for flattening of inspiratory flow loop on spirometry and lack of response to bronchodilators 1
• Young children (0-4 years): Diagnosis is challenging due to difficulty obtaining objective measurements; avoid labels like "wheezy bronchitis" that delay appropriate treatment 1

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Management Approach

Core Principles

Inhaled corticosteroids (ICS) are the cornerstone of treatment for all patients with persistent asthma, addressing the underlying inflammation rather than just symptoms—even patients with apparently mild asthma benefit from anti-inflammatory therapy. 1, 4

Four Components of Care

1. Assessment and monitoring of severity and control 1
2. Patient education for partnership in self-management 1
3. Environmental control and treatment of comorbidities 1
4. Pharmacologic therapy using stepwise approach 1

Stepwise Pharmacologic Management

Step 1 (Intermittent Asthma)

• Short-acting beta-agonist (SABA) as needed for symptom relief 1

Step 2 (Mild Persistent)

• Preferred: Low-dose ICS 1, 4
• Alternative: Leukotriene receptor antagonist or cromolyn 4

Step 3 (Moderate Persistent)

• Preferred: Low-dose ICS + long-acting beta-agonist (LABA), OR medium-dose ICS 1
• The combination ICS/LABA is equally preferred to increasing ICS dose in patients ≥5 years 1

Step 4 (Moderate-Severe Persistent)

• Medium-dose ICS + LABA 1

Step 5-6 (Severe Persistent)

• High-dose ICS + LABA 1
• Consider omalizumab for patients ≥12 years with allergic asthma requiring step 5-6 care 1

Monitoring and Adjustment

Once treatment is initiated, shift focus from assessing severity to assessing control—adjust therapy by stepping up or down based on achieving minimal symptoms, normal activity levels, and infrequent rescue inhaler use. 1

Goals of Control

• Minimal or no chronic symptoms, including nocturnal symptoms 1
• Minimal or no exacerbations 1
• No limitations on activities or exercise 1, 4
• Maintenance of (near) normal pulmonary function 1
• Minimal use of SABA (≤2 days/week) 1
• Minimal or no adverse effects from medications 1

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Management of Acute Exacerbations

Severity Assessment

Do not underestimate exacerbation severity—severe exacerbations can be life-threatening and occur in patients at any baseline severity level. 1

Features of Severe Exacerbation

• Too breathless to complete sentences in one breath 1
• Respiratory rate >25 breaths/min 1
• Heart rate >110 beats/min 1
• PEF <50% of predicted or personal best 1

Life-Threatening Features

• PEF <33% of predicted or personal best 1
• Silent chest, cyanosis, or feeble respiratory effort 1
• Bradycardia, hypotension, or arrhythmia 1
• Exhaustion, confusion, or altered consciousness 1
• Normal or elevated PaCO2 (5-6 kPa) in a breathless patient 1
• Severe hypoxia: PaO2 <8 kPa despite oxygen 1

Immediate Treatment

Administer high-dose inhaled beta-agonists and systemic corticosteroids immediately—early treatment is the best strategy for managing exacerbations. 1

Emergency Management Protocol

• Oxygen: Administer to correct hypoxemia, targeting SpO2 93-95% 1
• SABA: Salbutamol 5 mg or terbutaline 10 mg via nebulizer with oxygen, or 10-20 puffs via MDI with spacer 1
• Systemic corticosteroids: Prednisolone 30-60 mg orally OR hydrocortisone 200 mg IV immediately 1
• Ipratropium: Add 0.5 mg nebulized if life-threatening features present 1

Additional Therapies for Severe Exacerbations

• Magnesium sulfate: For severe exacerbations unresponsive to initial treatment 1
• Heliox: Consider for severe exacerbations unresponsive to initial treatment 1
• Aminophylline: 250 mg IV over 20 minutes (avoid if patient already on oral theophylline) 1

Hospital Discharge Criteria

Patients should not be discharged until PEF is >75% of predicted or personal best, with diurnal variability <25%, and no nocturnal symptoms. 1, 5

Discharge Medications (Essential)

• Prednisolone: 30-60 mg daily for 1-3 weeks (adults) or 1-2 mg/kg for 3-10 days (children, max 60 mg) 1, 5
• Inhaled corticosteroids: At higher dose than before admission, started at least 48 hours before discharge 1, 5
• SABA: For as-needed symptom relief 1, 5

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Patient Education and Self-Management

Written Asthma Action Plan

All patients must receive a written asthma action plan that specifies when to increase treatment, when to self-administer oral corticosteroids, and when to seek emergency care. 1, 5

Key Action Plan Elements

• Monitoring: Daily symptoms, PEF measurements, and medication use 1
• Green zone: Doing well—continue usual medications 1
• Yellow zone: Getting worse—increase ICS, start oral corticosteroids if PEF <60% of best 1
• Red zone: Medical emergency—take oral corticosteroids and seek immediate medical care 1

Self-Management Triggers

Patients should self-administer oral corticosteroids when 1:

• Symptoms and PEF progressively worsen day by day 1
• PEF falls below 60% of personal best 1
• Sleep is disturbed by asthma 1
• Morning symptoms persist until midday 1
• Diminishing response to inhaled bronchodilators 1

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Special Considerations

High-Risk Patients Requiring Intensive Monitoring

Patients at high risk of asthma-related death need special attention 1:

• Previous severe exacerbation (intubation or ICU admission) 1
• ≥2 hospitalizations or >3 ED visits in past year 1
• Use of >2 canisters of SABA per month 1
• Difficulty perceiving airway obstruction severity 1
• Major psychosocial problems or psychiatric disease 1

Specialist Referral Indications

Refer to respiratory physician when 1:

• Diagnostic uncertainty (atypical symptoms, alternative diagnoses) 1
• Continuing symptoms despite high-dose ICS 1
• Catastrophic sudden severe (brittle) asthma 1
• Consideration for long-term nebulized bronchodilators 1
• Recent hospital discharge 1
• Pregnant women with worsening asthma 1

Common Pitfalls to Avoid

• Overreliance on bronchodilators: Many asthma deaths are associated with inadequate anti-inflammatory treatment 1, 4
• Doubling ICS dose during exacerbations: This is not effective—use oral corticosteroids instead 1
• Underestimating exacerbation severity: Always obtain objective measurements (PEF, oxygen saturation) 1
• Sedation during acute exacerbations: Absolutely contraindicated 1
• Discharge without written action plan: Significantly increases relapse risk 5