What are the guidelines for using bronchodilators in patients with interstitial lung disease (ILD)?

Bronchodilator Use in Interstitial Lung Disease (ILD)

Bronchodilators are not routinely recommended for patients with interstitial lung disease (ILD) and should only be used in select patients who demonstrate a measurable bronchodilator response or have concurrent obstructive airway disease. 1

Assessment for Bronchodilator Therapy in ILD

The decision to use bronchodilators in ILD should be based on:

1. Documented bronchodilator response

   • Measure FEV1 before and after bronchodilator administration
   • Significant response: improvement in FEV1 ≥12% and ≥200 mL

2. Presence of concurrent airway disease

   • History of asthma or COPD
   • Evidence of airflow obstruction on PFTs
   • Wheezing on examination

Appropriate Use of Bronchodilators in ILD

When to Consider Bronchodilators:

• Patients with combined pulmonary fibrosis and emphysema
• ILD patients with documented bronchospasm
• Patients with significant symptom relief after bronchodilator trial
• Patients with connective tissue disease-associated ILD who may have airway involvement

When NOT to Use Bronchodilators:

• Patients with pure restrictive physiology without bronchodilator response
• Patients who show no symptomatic improvement with bronchodilator trial
• As primary therapy for ILD progression

Bronchodilator Selection and Administration

If a bronchodilator is indicated:

1. First-line options:

   • Short-acting bronchodilators (SABA) as needed for symptom relief
   • Long-acting bronchodilators for persistent symptoms

2. Delivery method:

   • Metered dose inhalers are preferred if patient technique is adequate 2
   • Consider spacer devices to improve delivery
   • Nebulizers should be reserved for patients who cannot use inhalers properly 2

3. Monitoring effectiveness:

   • Assess symptom improvement
   • Measure objective improvement in pulmonary function
   • Discontinue if no benefit is observed

Oxygen Therapy in ILD

While not bronchodilators, supplemental oxygen is an important supportive therapy for ILD patients:

• LTOT should be ordered for ILD patients with resting PaO2 ≤7.3 kPa 2
• LTOT should be considered for ILD patients with PaO2 ≤8 kPa if peripheral edema or pulmonary hypertension is present 2
• Portable oxygen therapy (POT) should be considered for ILD patients with severe breathlessness 2

Primary Treatment Approaches for ILD

The cornerstone of ILD management is not bronchodilator therapy but rather:

1. Disease-modifying therapies:

   • Mycophenolate mofetil is the preferred first-line agent for most connective tissue disease-associated ILDs 1
   • Nintedanib is recommended for systemic sclerosis-ILD and progressive fibrosing ILDs 1, 3
   • Pirfenidone is an alternative antifibrotic that can slow FVC decline by 44-57% 3

2. Immunosuppressive therapies for specific ILD subtypes:

   • Glucocorticoids for most CTD-ILD except systemic sclerosis 1
   • Tocilizumab as a conditional option for SSc-ILD 1
   • JAK inhibitors and calcineurin inhibitors for inflammatory myopathy-associated ILD 1

Monitoring and Follow-up

• Regular PFTs every 3-6 months for moderate-to-severe ILD
• HRCT imaging to assess progression
• Monitor for progression defined as:
  • Decline in FVC ≥10% predicted
  • Decline in FVC 5-10% with worsening symptoms or increased fibrosis on HRCT 1

Common Pitfalls to Avoid

1. Overreliance on bronchodilators when the primary pathology is restrictive
2. Failure to identify concurrent obstructive disease that might benefit from bronchodilators
3. Continuing bronchodilators despite lack of objective improvement
4. Neglecting primary disease-modifying therapy while focusing on symptomatic treatment
5. Delaying oxygen therapy in hypoxemic patients

In summary, while bronchodilators are not a primary treatment for ILD, they may provide symptomatic benefit in select patients with demonstrated bronchodilator response or concurrent obstructive disease. The main focus of therapy should remain on disease-modifying agents appropriate for the specific ILD subtype, with careful monitoring of disease progression and consideration of oxygen therapy when indicated.