What is the recommended treatment approach for managing asthma based on severity?

Asthma Management Based on Severity: A Stepwise Treatment Approach

The recommended treatment for asthma follows a stepwise approach where inhaled corticosteroids (ICS) form the foundation of therapy for all persistent asthma, with long-acting beta-agonists (LABAs) added for moderate-to-severe disease, and treatment intensity adjusted based on disease severity and control. 1

Initial Assessment and Classification

Before initiating therapy, classify asthma severity using both impairment and risk domains 1:

Impairment criteria:

• Symptom frequency (daytime and nighttime)
• SABA use for symptom relief
• Interference with normal activities
• Lung function (FEV₁ and FEV₁/FVC ratio) 1

Risk criteria:

• Frequency of exacerbations requiring oral corticosteroids
• History of hospitalizations or ICU admissions 1

Severity classifications:

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

Treatment by Severity Level

Step 1: Intermittent Asthma

• No daily controller medication needed 1
• Short-acting beta₂-agonist (SABA) as needed for symptom relief 1
• Oral corticosteroids may be required for exacerbations 1

Step 2: Mild Persistent Asthma

• Preferred: Low-dose ICS (fluticasone propionate 100-250 μg/day or equivalent) 1, 2
• Alternative options: Cromolyn, leukotriene modifier, or sustained-release theophylline 1
• SABA as needed for quick relief 1

Critical point: Low-dose ICS (200-250 μg fluticasone propionate equivalent) achieves 80-90% of maximum therapeutic benefit and should be the standard starting dose 2. Inhaled corticosteroids are the most effective anti-inflammatory medication available and are superior to cromolyn and nedocromil 1, 3.

Step 3: Moderate Persistent Asthma

• Preferred: Low-to-medium-dose ICS (fluticasone propionate 100-250 μg) PLUS long-acting inhaled beta₂-agonist (LABA) 1
• Alternative options:
  • Medium-dose ICS alone 1
  • Low-to-medium-dose ICS plus leukotriene modifier 1
  • Low-to-medium-dose ICS plus theophylline 1
• SABA as needed for quick relief 1

Evidence strength: Combination ICS/LABA therapy provides greater asthma control than increasing ICS dose alone, with superior outcomes compared to adding leukotriene modifiers or theophylline 4, 5. The combination product (e.g., fluticasone/salmeterol) delivers both anti-inflammatory and bronchodilator effects in a single inhaler, improving adherence 4.

Step 4: Severe Persistent Asthma

• Preferred: Medium-to-high-dose ICS (fluticasone propionate >250-500 μg) PLUS long-acting inhaled beta₂-agonist 1
• Alternative options:
  • Medium-to-high-dose ICS plus leukotriene modifier 1
  • Medium-to-high-dose ICS plus theophylline 1
• SABA as needed for quick relief 1

Steps 5-6: Most Severe Persistent Asthma

• Step 5 Preferred: High-dose ICS (fluticasone propionate >500 μg) PLUS LABA, and consider omalizumab for patients with allergies 1
• Step 6 Preferred: High-dose ICS PLUS LABA PLUS oral corticosteroids, and consider omalizumab for allergic patients 1
• Before introducing oral corticosteroids at Step 6, consider trial of high-dose ICS plus LABA plus a third agent (leukotriene receptor antagonist, theophylline, or zileuton), though this approach lacks clinical trial evidence 1

Monitoring and Adjusting Therapy

After initiating treatment, shift focus from severity to control assessment 1:

Schedule follow-up visits:

• Every 2-6 weeks when starting therapy or stepping up treatment 1
• Every 1-6 months once control is achieved 1
• Every 3 months if considering stepping down therapy 1

At each visit, assess:

• Asthma control using the same impairment and risk domains 1
• Medication technique and adherence 1
• Written asthma action plan 1
• Environmental triggers and comorbid conditions 1

Step up therapy if:

• Using SABA >2 days/week for symptom relief (not including exercise prevention) 1
• Using >1 canister of SABA per month 1
• Experiencing ≥2 exacerbations requiring oral corticosteroids per year 1

Step down therapy if:

• Asthma is well controlled for at least 3 months 1
• Goal: identify the minimum medication needed to maintain control 1

Critical Pitfalls to Avoid

LABA monotherapy is contraindicated: Never use LABA without ICS, as this increases risk of asthma-related death and hospitalization 6. LABAs must always be combined with ICS 6.

Monitor for excessive ICS dosing: Doses >500 μg/day fluticasone propionate equivalent carry increased risk of systemic adverse effects (cataracts, reduced bone density) with diminishing additional benefit 1, 2. The dose-response curve for ICS is relatively flat beyond low-to-medium doses 3, 2.

Recognize underestimation of severity: Acute severe asthma is often underestimated by patients and physicians due to failure to make objective measurements 1. Always measure peak expiratory flow or spirometry 1.

Address adherence issues: Poor adherence to ICS maintenance therapy increases risk of severe exacerbations and death 7. Consider as-needed ICS strategies for patients with adherence challenges 7.

Specialist Referral Indications

Refer to an asthma specialist when 1:

• Difficulty achieving or maintaining control
• Patient required ≥2 bursts of oral corticosteroids in 1 year
• Exacerbation requiring hospitalization
• Step 4 care or higher is required (Step 3 or higher for children 0-4 years)
• Considering immunotherapy or omalizumab
• Additional testing is indicated

Acute Severe Asthma Management

Life-threatening features requiring immediate treatment 1:

• Peak expiratory flow <33% predicted
• Silent chest, cyanosis, or feeble respiratory effort
• Bradycardia or hypotension
• Exhaustion, confusion, or coma
• Normal or high PaCO₂ (5-6 kPa) in breathless patient
• Severe hypoxia (PaO₂ <8 kPa) despite oxygen 1

Immediate treatment 1:

• High-dose inhaled beta-agonist (salbutamol 5 mg or terbutaline 10 mg nebulized)
• High-dose systemic steroids (prednisolone 30-60 mg or IV hydrocortisone 200 mg)
• Add ipratropium 0.5 mg nebulized if life-threatening features present
• Consider IV aminophylline or IV beta-agonist for life-threatening attacks 1