What is the recommended approach for an asthma workup and treatment?

Comprehensive Approach to Asthma Workup and Treatment

The recommended approach for asthma workup includes objective measurement of lung function through spirometry, assessment of symptom frequency and severity, identification of triggers, and implementation of a stepwise treatment approach based on asthma severity and control level. 1

Diagnostic Evaluation

• Perform spirometry to confirm diagnosis by demonstrating variable airflow obstruction, with FEV1/FVC ratio assessment and bronchodilator reversibility testing 1, 2
• Assess peak expiratory flow (PEF) measurements to establish baseline and monitor variability 1
• Consider methacholine or mannitol challenge tests if spirometry is normal but symptoms suggest asthma 3
• Evaluate for common diagnostic challenges including cough variant asthma, vocal cord dysfunction, and comorbidities like GERD and obstructive sleep apnea 1, 4
• Document frequency of symptoms, nighttime awakenings, activity limitations, and rescue medication use to classify severity 1

Classification of Asthma

• Categorize asthma as intermittent or persistent (mild, moderate, or severe) based on symptom frequency, nighttime awakenings, and lung function 1, 3
• Assess both current impairment (symptoms, lung function, activity limitations) and future risk (exacerbations, medication side effects, lung function decline) 1
• Consider asthma phenotypes: allergic (IgE-mediated), non-allergic, occupational, aspirin-exacerbated respiratory disease, exercise-induced, or cough variant 3

Treatment Approach

Step 1: Initial Assessment and Control

• For newly diagnosed patients, assess asthma severity to determine initial treatment level 1
• For patients already on treatment, assess asthma control to guide adjustments 1
• Use validated questionnaires like Asthma Control Test (ACT) or Asthma Control Questionnaire (ACQ) to standardize assessment 1

Step 2: Implement Stepwise Treatment

• For intermittent asthma: Short-acting beta-agonists (SABA) like albuterol as needed 1, 5
• For persistent asthma: Daily inhaled corticosteroids (ICS) as foundation of therapy, with step-up options including:
  • Mild persistent: Low-dose ICS 1
  • Moderate persistent: Low-dose ICS plus long-acting beta-agonist (LABA) or medium-dose ICS 1
  • Severe persistent: Medium to high-dose ICS plus LABA, with consideration of add-on therapies 1

Step 3: Consider Add-on Therapies for Difficult-to-Control Asthma

• Leukotriene receptor antagonists (LTRAs) 1
• Tiotropium (long-acting muscarinic antagonist) 1
• Biologics like omalizumab for allergic asthma with elevated IgE levels 1, 6
• Oral corticosteroids for severe, uncontrolled asthma 1

Monitoring and Follow-up

• Assess asthma control at regular intervals (every 2-6 weeks initially, then every 1-6 months) 1
• Monitor lung function with spirometry or peak flow measurements 1
• Step up treatment if control is not achieved; step down if control is maintained for at least 3 months 1
• Track exacerbation frequency - patients with ≥2 exacerbations requiring oral corticosteroids in the past year should be considered to have not well-controlled asthma 1

Special Considerations

• Evaluate and manage comorbidities that can worsen asthma control (rhinitis, sinusitis, GERD, obesity, obstructive sleep apnea) 1, 4
• Consider referral to an asthma specialist if:
  • Diagnosis is uncertain or additional testing is needed 1
  • Patient required >2 bursts of oral corticosteroids in one year 1
  • Step 4 care or higher is required (Step 3 or higher for children 0-4 years) 1
  • Immunotherapy or biologics like omalizumab are being considered 1, 6

Acute Exacerbation Management

• Assess severity using objective measures (PEF, oxygen saturation) and clinical signs 1
• Administer high-dose inhaled beta-agonists (salbutamol 5mg or terbutaline 10mg) via nebulizer or spacer 1
• Give systemic corticosteroids (prednisolone 30-60mg or IV hydrocortisone 200mg) 1
• Consider hospital admission for severe exacerbations, especially with poor response to initial treatment 1
• Monitor response to treatment with repeated PEF measurements 1

Common Pitfalls to Avoid

• Relying solely on symptoms without objective lung function measurements can lead to under-diagnosis or under-treatment 2, 7
• Failing to distinguish between poor asthma control and acute exacerbation 8
• Neglecting to assess and address poor medication adherence before stepping up therapy 1
• Not providing patient education on proper inhaler technique, trigger avoidance, and self-management plans 1, 8
• Overlooking the need for regular follow-up and monitoring of lung function over time 1

By following this comprehensive approach to asthma workup and treatment, clinicians can effectively diagnose, classify, and manage asthma to reduce morbidity and improve quality of life for patients with this common respiratory condition.