How to evaluate and manage asthma?

Evaluation and Management of Asthma

Establish the diagnosis using spirometry in all patients ≥5 years old to demonstrate reversible airflow obstruction, then classify severity to initiate treatment and subsequently monitor control to adjust therapy using a stepwise approach. 1

Initial Diagnosis

Clinical Assessment

• Document recurrent episodes of airflow obstruction including wheezing, breathlessness, chest tightness, and cough (particularly at night or early morning) 1
• Obtain detailed history focusing on:
  • Symptom frequency (daytime and nighttime) 1
  • Activity limitations and school/work attendance 1
  • Frequency of short-acting β-agonist (SABA) use 1
  • Previous exacerbations, ED visits, hospitalizations, and ICU admissions 2
  • Trigger exposures (allergens, irritants, exercise, infections, medications) 1, 2
  • Current medication use and adherence 3

Objective Testing

• Perform spirometry at initial assessment in all patients ≥5 years old 1
• Demonstrate reversibility: FEV₁ improvement ≥12% and ≥200 mL after bronchodilator administration 1
• Consider bronchoprovocation testing (methacholine, histamine, exercise) when spirometry is normal but asthma is suspected—a negative test helps rule out asthma 1
• Measure peak expiratory flow in children and when spirometry unavailable 1

Exclude Alternative Diagnoses

Critical differential diagnoses to rule out include 1:

• Adults: COPD, congestive heart failure, vocal cord dysfunction, pulmonary embolism, ACE inhibitor-induced cough 1
• Children: foreign body aspiration, cystic fibrosis, vascular rings, recurrent aspiration 1, 4
• All ages: vocal cord dysfunction (look for inspiratory flow-volume loop flattening on spirometry) 1

Severity Classification (Treatment-Naïve Patients)

Classify severity before initiating therapy using both impairment and risk domains 1:

Impairment Domain

• Intermittent: Symptoms ≤2 days/week, nighttime awakenings ≤2×/month, SABA use ≤2 days/week, no interference with activities, 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, some activity limitation, FEV₁ 60-80% predicted 1
• Severe Persistent: Symptoms throughout the day, nighttime awakenings often 7×/week, extreme activity limitation, FEV₁ <60% predicted 1

Risk Domain

• Assess exacerbation history: ≥2 exacerbations requiring oral corticosteroids in past year indicates higher risk 1

Stepwise Pharmacotherapy

Quick-Relief Medication (All Patients)

• SABA as needed for symptom relief: up to 3 treatments at 20-minute intervals 1
• SABA use >2 days/week (excluding exercise prophylaxis) indicates inadequate control requiring step-up 1

Long-Term Control by Severity

Step 1 (Intermittent): SABA as needed only 1

Step 2 (Mild Persistent): Low-dose inhaled corticosteroid (ICS) 1

Step 3 (Moderate Persistent): Low-dose ICS + long-acting β-agonist (LABA), OR medium-dose ICS 1

• Alternative: Low-dose ICS + leukotriene receptor antagonist (LTRA) or theophylline 1

Step 4: Medium-dose ICS + LABA 1

• Alternative: Medium-dose ICS + LTRA or theophylline 1

Step 5 (Severe Persistent): High-dose ICS + LABA 1

• Consider omalizumab for allergic asthma 1

Step 6: High-dose ICS + LABA + oral corticosteroids 1

• Consider omalizumab for IgE-mediated disease 1

Ongoing Monitoring and Control Assessment

Visit Frequency

• Every 2-6 weeks when initiating therapy or stepping up 1
• Every 1-6 months once control achieved 1
• Every 3 months when considering step-down 1

Control Assessment (≥12 Years Old)

Well-Controlled 1:

• Symptoms ≤2 days/week
• Nighttime awakenings ≤2×/month
• SABA use ≤2 days/week
• No activity interference
• FEV₁ >80% predicted
• 0-1 exacerbations/year

Not Well-Controlled 1:

• Symptoms >2 days/week
• Nighttime awakenings 1-3×/week
• SABA use >2 days/week
• Some activity limitation
• FEV₁ 60-80% predicted
• ≥2 exacerbations/year

Very Poorly Controlled 1:

• Daily symptoms
• Nighttime awakenings ≥4×/week
• SABA use several times daily
• Extreme activity limitation
• FEV₁ <60% predicted

Objective Monitoring

• Perform spirometry at least every 1-2 years, more frequently if poorly controlled 1
• Consider daily peak flow monitoring for moderate-severe persistent asthma, history of severe exacerbations, or poor symptom perception 1

Adjusting Therapy

Step Up

Before stepping up, verify 1:

• Medication adherence
• Correct inhaler technique
• Environmental trigger control
• Treatment of comorbidities (rhinitis, sinusitis, GERD, OSA, obesity) 1

Step up 1-2 steps if not well-controlled or very poorly controlled 1

Step Down

• Consider after ≥3 months of well-controlled asthma 1
• Monitor closely at 3-month intervals during step-down 1

Patient Education and Self-Management

Essential Components

• Develop written asthma action plan with instructions for daily management and managing worsening symptoms 1
• Teach proper inhaler technique and verify at every visit 1
• Train self-monitoring using either symptoms or peak flow (benefits are similar) 1
• Identify and avoid triggers: allergens, tobacco smoke, irritants, infections 1
• Distinguish long-term control from quick-relief medications 1

Environmental Control

• Multifaceted allergen avoidance for sensitized patients with persistent asthma (single interventions generally ineffective) 1
• All patients must avoid tobacco smoke exposure 1
• Consider allergen immunotherapy when clear relationship between symptoms and specific allergen exposure 1

Specialist Referral Indications

Refer for consultation or co-management when 1:

• Difficulty achieving or maintaining control
• ≥2 oral corticosteroid bursts in past year
• Any hospitalization for asthma
• Step 4+ care required (Step 3+ for ages 0-4 years)
• Immunotherapy or omalizumab considered
• Additional diagnostic testing needed

Acute Severe Asthma Recognition

Immediate treatment required if 1, 2:

• Accessory muscle use, difficulty speaking, refusal to recline
• Pulse >120 beats/min, decreased breath sounds 2
• Peak flow ≤50% predicted or personal best 1
• Oxygen saturation <90% 2

Emergency management: High-flow oxygen, nebulized albuterol + ipratropium, systemic corticosteroids (benefits begin 6-12 hours after administration) 2