Asthma¶
Faria Khimani
Definition¶
- Chronic inflammatory bronchial hyperresponsiveness, with episodic exacerbations and reversible airflow obstruction
- Prevalence: 5-10% US population
Risk Factors¶
- Family history of asthma, history of allergies, atopic dermatitis, low SES
Presentation¶
- History of cough, recurrent wheezing, recurrent difficulty breathing, recurrent chest tightness
- Symptoms occur or worsen at night or with exercise, viral infection, exposure to allergens and irritants, changes in weather, hard laughing or crying, stress, or other factors
Diagnostics¶
- First line is spirometry. (do NOT need full PFTs)
- Asthma diagnosis most likely with evidence of obstructive disease AND excessive variability in lung function as measured by:
- FEV1 reduction w/ FEV1/FVC reduced compared to lower limit of normal (>0.75-0.80 in adults)
- Positive bronchodilator responsiveness: Increase in FEV1 >12% and >200L
- Must rule out other common differentials: Panic attacks, upper airway obstruction or infection, foreign body, COPD, ILD, vocal cord dysfunction, CHF, ACE-i induced cough, OSA
- CBC may show eosinophilia
- If concerned for allergic asthma or allergic bronchopulmonary aspergillosis, consider measuring total serum IgE levels
Classify Severity and Assess for Symptom Control with the RULE OF 2s¶
- Does the pt have symptoms or require rescue inhaler ≥2 times per week?
- Does the pt endorse nighttime symptoms ≥ 2 times per month?
- Does the pt use rescue inhaler ≥ 2 times per week?
- Does the pt ever have to limit activity due to asthma symptoms?
| Severity of asthma | Impairment over a month | FEV1 |
|---|---|---|
| Intermittent | No to all the above | >80% predicted |
| Mild persistent | Symptoms < daily, nighttime symptoms < weekly, SABA use < daily, minor activity limitations | >80% predicted |
| Moderate persistent | Symptoms daily, nighttime symptoms ≥ weekly, SABA use daily, some activity limitations | 60-79% predicted |
| Severe persistent | Symptoms all day, nighttime symptoms daily, SABA use > daily, extreme activity limitations | <60% predicted |
Management¶
- Aim to use the lowest possible step to maintain symptom control. Also consider stepping down therapy if pt has been well-controlled for >3 months
- Prior to escalating therapy, consider
- Adherence to therapy (including inhaler technique), uncontrolled comorbidities (allergies, GERD, OSA, etc), and alternative diagnoses
- Ensure pts receive MDI and spacer teaching for full effect
- Updated Guidelines: PRN ICS - LABA > PRN SABA Step 1 (mild intermittent) and Step 2 (mild persistent). Reduces exacerbations, easier to schedule does in future if needed
Follow-up¶
- Repeat PFTs q3-6 mos after beginning therapy and q1-2 yrs thereafter
- Follow-up appointment 1-3mos after initiating therapy, every 3-12 mo thereafter
VA specific guidance¶
- Mometasone is the formulary ICS and Wixela (fluticasone-salmeterol) is the formulary ICS/LABA
Ordering PFTs¶
- Refer to Pulm section on PFTs for VUMC and VA specifics
| Guideline | Step 1 | Step 2 | Step 3 | Step 4 | Step 5 | Step 6 |
|---|---|---|---|---|---|---|
| GINA 2023 | PRN Low dose ICS-LABA (budesonide-formoterol) | PRN low-dose ICS-LABA (budesonide-formoterol) | Daily + PRN-low dose ICS-LABA | Daily medium-dose ICS-LABA + PRN low-dose ICS-LABA | Consider: High-dose ICS-LABA x3-6mo; add LAMA; or additional therapies (biologics, azithro, or low-dose PO glucocorticoids) | N/A |
| NAEPP 2020 | Intermittent: PRN SABA | Mild persistent: PRN SABA + daily low-dose ICS (budesonide) | Moderate persistent: Daily +PRN low-dose ICS-LABA Alt: PRN SABA + daily medium-dose ICS-LABA |
Moderate persistent refractory: Daily + PRN medium-dose ICS-LABA | Severe persistent: Daily medium or high-dose ICS-LABA + daily LAMA + PRN SABA | Severe persistent refractory: Daily high-dose ICS-LABA + oral glucocorticoids + PRN SABA |