Treatment Rationale for Asthma Management
Asthma treatment is fundamentally based on controlling chronic airway inflammation with inhaled corticosteroids (ICS) as first-line therapy, combined with bronchodilators for symptom relief, using a stepwise approach that escalates therapy based on disease severity and control. 1, 2
Core Pathophysiologic Rationale
The treatment strategy targets the underlying inflammatory process that characterizes asthma, rather than merely treating symptoms. ICS suppress inflammation in asthmatic airways and inhibit almost every aspect of the inflammatory cascade, making them the only currently available therapy that addresses the root pathophysiology. 3 This anti-inflammatory effect not only controls symptoms and improves lung function but also prevents exacerbations, reduces mortality risk, and may prevent irreversible airway remodeling. 3
Stepwise Treatment Algorithm
Initial Therapy Selection
For patients with persistent asthma symptoms, initiate ICS at a standard daily dose of 200-250 μg fluticasone propionate equivalent, which achieves 80-90% of maximum therapeutic benefit. 4 This represents the optimal balance between efficacy and safety, as higher doses provide minimal additional benefit but significantly increase systemic adverse effects. 5, 4
For patients aged 12 years and older with moderate asthma, start with ICS/long-acting beta-agonist (LABA) combination therapy (fluticasone 100-250 μg/salmeterol 50 μg twice daily). 6 For children aged 4-11 years, use fluticasone 100 μg/salmeterol 50 μg twice daily. 6
Escalation Strategy
When asthma remains symptomatic despite standard-dose ICS, adding a LABA is superior to doubling the ICS dose. 7 The combination of salmeterol 50 μg and fluticasone 250 μg produces significantly greater improvements in peak expiratory flow (16.6 L/min difference), symptom-free days (12.6% more days), and quality of life compared to doubling fluticasone to 500 μg. 7
The dose-response curve for ICS is relatively flat beyond standard doses, making combination therapy with LABA, low-dose theophylline, or leukotriene receptor antagonists preferable to high-dose ICS monotherapy. 3
High starting doses of ICS provide no additional clinical benefit in 3 of 4 efficacy parameters compared to low or moderate doses but carry potential safety concerns. 5
Acute Exacerbation Management
Immediate Treatment Protocol
For acute severe asthma (respiratory rate >25/min, heart rate >110/min, PEF <50% predicted, inability to complete sentences), immediately administer high-dose inhaled beta-agonists (salbutamol 5 mg or terbutaline 10 mg nebulized) and systemic corticosteroids (prednisolone 30-60 mg or IV hydrocortisone 200 mg). 1, 2
If life-threatening features present (PEF <33%, silent chest, cyanosis, exhaustion, confusion), add nebulized ipratropium 0.5 mg to beta-agonist therapy and consider IV aminophylline 250 mg over 20 minutes or IV salbutamol/terbutaline 250 μg over 10 minutes. 1
Corticosteroids require 6-12 hours to manifest anti-inflammatory effects, making early administration critical for preventing mortality. 8
Response Assessment
Reassess peak expiratory flow 15-30 minutes after initial treatment to determine hospitalization need. 1, 8 If PEF remains <33% predicted or severe features persist, immediate hospital admission is required. 1
Continue nebulized beta-agonists every 4 hours if improving, or every 15 minutes if no improvement after initial treatment. 1
Critical Treatment Principles
What NOT to Do
Never use sedatives in asthmatic patients—they are absolutely contraindicated and can worsen respiratory depression. 1, 2, 9
Do not prescribe antibiotics unless bacterial infection is clearly documented—elevated inflammatory markers alone do not justify antibiotic use. 1, 2, 9
Avoid percussive physiotherapy during acute exacerbations as it provides no benefit. 1
Do not discharge patients on inadequate steroid courses—the standard 5-6 day methylprednisolone dose pack is often insufficient; use prednisolone 30-60 mg daily for 1-3 weeks to prevent relapse. 8
Monitoring Requirements
Measure and record peak expiratory flow 15-30 minutes after starting treatment and according to response thereafter. 1, 2
For hospitalized patients, continue high-dose steroids (prednisolone 30-60 mg daily or IV hydrocortisone 200 mg every 6 hours) until significant improvement. 1
Patients should not be discharged until PEF >75% predicted, diurnal variability <25%, and no nocturnal symptoms. 1
Discharge and Long-Term Management
All discharged patients require prednisolone 30-60 mg daily for 1-3 weeks, increased inhaled corticosteroid dose, and as-needed beta-agonists. 1, 8
Provide peak flow meter and written asthma action plan at discharge. 8
Schedule primary care follow-up within 1 week and respiratory specialist within 4 weeks. 8
Special Considerations
As-Needed ICS Strategies
- For patients with poor adherence to daily maintenance therapy, as-needed ICS-formoterol strategies can reduce severe exacerbations by empowering patients to adjust ICS intake in response to symptom fluctuation. 10
Intensive Care Criteria
Transfer to ICU with physician prepared to intubate if: deteriorating PEF, worsening hypoxia (PaO₂ <8 kPa) despite 60% oxygen, hypercapnia (PaCO₂ >6 kPa), exhaustion, confusion, drowsiness, or respiratory arrest. 1
Mechanical ventilation required for worsening hypoxia/hypercapnia, drowsiness, unconsciousness, or respiratory arrest. 1