What is the management approach for a patient with acute asthma exacerbation?

Management of Acute Asthma Exacerbation

Immediately administer high-flow oxygen (40-60%) to maintain oxygen saturation >90% and nebulized salbutamol 5 mg (or terbutaline 10 mg) via oxygen-driven nebulizer, along with oral prednisolone 30-60 mg or IV hydrocortisone 200 mg, as these three interventions form the cornerstone of acute asthma management and must be initiated without delay. 1, 2, 3

Initial Assessment and Severity Classification

Assess severity objectively using the following parameters, as subjective clinical assessment alone is often inaccurate 4:

Moderate Exacerbation

• Able to speak in complete sentences 1, 3
• Pulse <110 beats/min 1
• Respiratory rate <25 breaths/min 1
• Peak expiratory flow (PEF) >50% of predicted or personal best 1

Severe Exacerbation

• Cannot complete sentences in one breath 1, 3
• Pulse >110 beats/min 1
• Respiratory rate >25 breaths/min 1
• PEF <50% of predicted or personal best 1
• Oxygen saturation <90% 2

Life-Threatening Features (Require Immediate ICU Consideration)

• Silent chest, cyanosis, or feeble respiratory effort 1, 3
• Bradycardia or hypotension 1
• Exhaustion, confusion, or coma 1
• PEF <33% of predicted or personal best 1, 5

Critical pitfall: Patients with severe or life-threatening asthma may be distressed and not exhibit all abnormalities—the presence of any single life-threatening feature should trigger immediate escalation of care 1.

Immediate Treatment Protocol

First-Line Therapy (All Patients)

Oxygen therapy:

• Administer 40-60% oxygen via face mask to maintain saturation >90% (>95% in pregnant patients or those with cardiac disease) 1, 2, 5
• Continue oxygen monitoring continuously until clear response to bronchodilator therapy occurs 2, 5

Short-acting beta-agonist:

• Nebulized salbutamol 5 mg or terbutaline 10 mg via oxygen-driven nebulizer 1, 3, 6
• Alternative: 2-10 puffs (200-1000 μg) via metered-dose inhaler with large-volume spacer, repeated 10-20 times if no nebulizer available 1, 2
• Repeat every 20 minutes for up to 3 doses in the first hour 5, 7
• Reassess at 15-30 minutes after each nebulizer treatment 1

Systemic corticosteroids (essential for all moderate-to-severe exacerbations):

• Oral prednisolone 30-60 mg OR IV hydrocortisone 200 mg 1, 2, 3
• Administer within the first hour, as clinical benefits require 6-12 hours to manifest 4, 7
• Continue for 5-7 days 2, 8
• Critical pitfall: Underuse of corticosteroids is a common factor in preventable asthma deaths 1, 3

Additional Therapy for Severe Exacerbations

Ipratropium bromide:

• Add 0.5 mg nebulized ipratropium to beta-agonist for severe exacerbations 1, 3
• Dosing: 0.25-0.5 mg every 20 minutes for 3 doses, then every 4-6 hours as needed 2, 7
• This combination improves lung function and decreases hospitalization rates in severe cases 7

Intravenous magnesium sulfate:

• Administer 2 g IV over 20 minutes in patients with severe exacerbations not responding to initial treatment 2, 8
• Significantly increases lung function and decreases hospitalization necessity 7

Aminophylline (life-threatening cases only):

• 250 mg IV over 20 minutes for life-threatening features 1, 3
• Critical warning: Exercise extreme caution if patient is already taking oral theophyllines—do not give bolus aminophylline 1, 5

Monitoring and Reassessment

Reassess 15-30 minutes after each nebulizer treatment 1:

If PEF improves to >75% predicted/best:

• Step up usual maintenance treatment 1
• Arrange follow-up within 48 hours 1

If PEF 50-75% predicted/best:

• Continue beta-agonists 1
• Ensure prednisolone has been administered 3
• Arrange follow-up within 24 hours 1

If any severe features persist after initial treatment:

• Arrange immediate hospital admission 1
• Repeat nebulized ipratropium 0.5 mg 1
• Consider IV magnesium sulfate 2

Hospital Admission Criteria

Admit to hospital if: 1

• Any life-threatening features present 1
• Any features of acute severe asthma persist after initial treatment, especially PEF <33% 1
• Attack occurs in afternoon/evening 1
• Recent hospital admission or previous severe attacks 1
• Recent nocturnal symptoms or frequent beta-agonist use 1

Discharge Criteria and Follow-Up

Discharge is appropriate when: 2

• Clinical stability achieved 2
• Oxygen saturation normalized 2
• PEF or FEV1 improved to 60-80% of predicted 8
• Normal respiratory rate and absence of chest wall retractions 2

At discharge, ensure: 1, 8

• Patient has adequate supply of medications and correct inhaler technique 1
• Written asthma action plan provided 1, 8
• PEF monitoring chart given 1
• Follow-up arranged within 24-48 hours depending on severity 1
• Consider stepping up maintenance therapy 1, 8
• Patient instructed to return immediately if symptoms worsen 1

Special Considerations

Alternative delivery methods:

• MDI with large-volume spacer is as effective as nebulized therapy when administered correctly, particularly useful in mild-to-moderate exacerbations 1, 5, 9
• Nebulizer therapy may be preferred in patients unable to cooperate with MDI due to age, agitation, or severity 5

Subcutaneous options (if beta-agonist inhalation not possible):

• Subcutaneous epinephrine 0.3-0.5 mg or terbutaline 0.25 mg every 20 minutes for up to 3 doses 1, 5

Chest radiography:

• Obtain in life-threatening cases to exclude pneumothorax 1