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, while simultaneously assessing severity through objective measurements including peak expiratory flow, respiratory rate, heart rate, and ability to speak in complete sentences. 1, 2, 3

Initial Severity Assessment

Assess severity immediately using objective criteria rather than subjective clinical impression alone, as physicians often underestimate airway obstruction 4:

Moderate Exacerbation (Can Treat at Home with Close Monitoring)

• Speech normal, can complete sentences 1
• Pulse <110 beats/min 1
• Respiratory rate <25 breaths/min 1
• Peak expiratory flow (PEF) >50% of predicted or personal best 1

Severe Exacerbation (Consider Hospital Admission)

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

Life-Threatening Features (Immediate Hospital Transfer)

• Silent chest, cyanosis, or feeble respiratory effort 1, 3
• PEF <33% of predicted or personal best 1, 5
• Bradycardia, hypotension 1, 3
• Exhaustion, confusion, or coma 1, 3
• Oxygen saturation <90% despite supplemental oxygen 2

Immediate First-Line Treatment (All Severity Levels)

Oxygen Therapy

• Administer 40-60% oxygen via face mask immediately to all patients 1, 2, 3
• Target oxygen saturation >90% (>95% in pregnant patients or those with cardiac disease) 2, 5
• Monitor continuously until clear response to bronchodilator therapy occurs 2, 5

Inhaled Beta-2 Agonists

• Nebulized route: Salbutamol 5 mg or terbutaline 10 mg via oxygen-driven nebulizer 1, 2, 3
• Alternative MDI route: 2 puffs of beta-agonist via large volume spacer, repeated 10-20 times if no nebulizer available 1
• Repeat every 20 minutes for up to 3 treatments in the first hour 2, 5, 6
• Reassess 15-30 minutes after each nebulizer treatment 1

Systemic Corticosteroids (Critical - Do Not Delay)

• Oral route (preferred if patient can swallow): Prednisolone 30-60 mg 1, 2, 3
• IV route: Hydrocortisone 200 mg or methylprednisolone 1-2 mg/kg 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. Many deaths occur because patients or physicians fail to appreciate severity and delay corticosteroid administration 1.

Additional Treatment for Severe/Life-Threatening Exacerbations

Ipratropium Bromide (Add to Beta-Agonists)

• Nebulized ipratropium 0.5 mg every 20 minutes for 3 doses, then every 4-6 hours 2, 3
• Alternatively, 4-8 puffs via MDI with spacer every 20 minutes 2
• Combination therapy improves lung function and decreases hospitalization in severe exacerbations 7

Intravenous Magnesium Sulfate

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

Aminophylline (Life-Threatening Features Only)

• 250 mg IV over 20 minutes 1, 3
• Critical Pitfall: Use extreme caution if patient already taking oral theophyllines - risk of toxicity 1

Monitoring and Reassessment Protocol

Reassess every 15-30 minutes after treatment 1:

If PEF Improves to >75% Predicted/Best

• Step up usual maintenance treatment 1
• Arrange follow-up within 48 hours 1
• Provide written asthma action plan 1

If PEF 50-75% Predicted/Best

• Continue prednisolone 30-60 mg 1
• Continue regular inhaled corticosteroid and beta-agonist 1
• 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 or give subcutaneous terbutaline 1
• Patient must be accompanied by nurse or doctor at all times during transfer 1

Hospital Admission Criteria

Admit if any of the following present:

• Any life-threatening features 1
• Features of acute severe asthma persist after initial treatment, especially PEF <33% 1
• Attack occurs in afternoon or evening 1
• Recent hospital admission or previous severe attacks 1
• Patient unable to assess own condition or poor social circumstances 1

Special Considerations for Catastrophic Sudden Severe Asthma

Some patients develop severe asthma within minutes to hours despite previous stability 1:

• These patients require a pre-arranged management plan with GP and respiratory specialist 1
• Should carry Medic-Alert bracelet 1
• May benefit from home resuscitation box with preloaded epinephrine syringe (0.5 mg subcutaneous) 1
• Direct admission to intensive care unit may be appropriate 1

Discharge Planning and Follow-Up

Before discharge, ensure 1, 8:

• Symptoms improved and PEF 60-80% of predicted 8
• Patient has adequate supply of medications 1
• Inhaler technique verified as correct 1
• Written asthma action plan provided 1, 8
• Follow-up arranged within 24-48 hours depending on severity 1
• Consider stepping up maintenance therapy 8

Critical Pitfall: Do not discharge patients in afternoon/evening with marginal improvement, as this increases risk of deterioration 1.