What is the role of budesonide (corticosteroid) nebulization in treating acute bronchial asthma?

Nebulized Budesonide in Acute Bronchial Asthma

Nebulized budesonide is NOT recommended as first-line therapy for acute severe asthma in adults, where oral or intravenous systemic corticosteroids (prednisolone or hydrocortisone) remain the standard of care alongside nebulized bronchodilators and oxygen. 1

Standard Treatment for Acute Severe Asthma

The British Thoracic Society guidelines establish the definitive approach for acute severe asthma 1:

Adults with Acute Severe Asthma

• Severity criteria: Cannot complete sentences, respiratory rate >25/min, heart rate >110/min, peak expiratory flow <50% best 1
• First-line treatment: Oxygen plus oral steroids (prednisolone 40 mg or hydrocortisone 100 mg IV six hourly) plus nebulized β-agonist (salbutamol 5 mg or terbutaline 10 mg), repeated 4-6 hourly if improving 1
• If not improving, add ipratropium bromide 500 µg to β-agonist and consider hospital admission 1

Children with Acute Severe Asthma

• Severity criteria: Cannot talk or feed, respiratory rate >50/min, heart rate >140/min, peak expiratory flow <50% predicted 1
• Treatment: Oxygen plus nebulized salbutamol 5 mg (or 0.15 mg/kg) or terbutaline 10 mg (or 0.3 mg/kg) repeated 1-4 hourly if better 1
• If not improving, repeat at 30 minutes after adding ipratropium bromide 250 µg, continue hourly, and consider transfer to hospital and oral steroids 1

Limited Role of Nebulized Corticosteroids

The 1997 British Thoracic Society guidelines explicitly state: "There are at present no published randomised controlled trials of the effectiveness of nebulised corticosteroids in adults with asthma" and recommend that patients be reviewed by a respiratory specialist before nebulized corticosteroids are prescribed 1

When Nebulized Budesonide May Be Considered

Despite guideline limitations, more recent research suggests potential benefit in specific scenarios:

In children with moderate-to-severe exacerbations:

• High-dose nebulized budesonide (1 mg per dose, three doses in first hour) added to bronchodilators resulted in significantly greater improvement in lung function at 1-2 hours post-treatment compared to bronchodilators alone 2
• Complete remission rate was significantly higher (84.7% vs 46.3%) and need for oral corticosteroids significantly lower (16.9% vs 46.3%) with budesonide 2
• This suggests nebulized high-dose budesonide can be used as first-line therapy for non-life-threatening acute exacerbations in children 2

In adults with good response to initial bronchodilator therapy:

• In patients showing >50% increase in FEV₁ after first-line bronchodilator therapy, nebulized budesonide 4 mg/day may be used instead of systemic corticosteroids 3
• For patients with poor initial response (FEV₁ <40% after bronchodilators), adding nebulized budesonide 4 mg/day to oral prednisolone 30 mg/day enhanced treatment efficiency and reduced systemic steroid requirements 3

In moderate-severe attacks:

• Nebulized budesonide (4 mg/day) with or without systemic corticosteroids improved airway obstruction and symptoms by day 1 compared to systemic corticosteroids alone, with effects lasting 7 days 4
• FEV₁ levels increased significantly at first day with nebulized budesonide but not until day 5 with systemic corticosteroids alone 4

Dosing When Used

• High-dose regimen: 1 mg per dose, three doses in first hour, then continued as needed 2
• Standard regimen: 4 mg/day divided doses 3, 4
• Efficacy benefits from high doses given repeatedly during initial phase of acute exacerbation 5

Critical Caveats

The evidence for nebulized budesonide remains limited:

• The 1997 BTS guidelines note controlled trials are "urgently needed to establish the role of nebulised corticosteroids compared with increased doses given by hand held inhalers" 1
• In mild-to-moderate exacerbations, nebulized budesonide showed only a trend toward benefit (not statistically significant) in preventing need for systemic corticosteroids 6
• The documented benefit is small and requires consideration of cost-effectiveness, practicality, and safety 6

Systemic corticosteroids remain the evidence-based standard:

• Oral prednisolone or IV hydrocortisone have established efficacy in acute asthma 1
• Oxygen should be used as the driving gas for nebulizers whenever possible 1
• Treatment should not be delayed to attempt nebulized corticosteroids when systemic steroids are indicated 1