for Health Care Providers
Note: Some medications mentioned in this chapter may not be available on the VHA National Formulary. Consult VA pharmacists for alternatives.
- Asthma is characterized by airway hyperresponsiveness, inflammation, and reversible obstruction.
- Stepwise, multimodal treatment of asthma may decrease symptoms.
- Patients should know their baseline peak expiratory flow rate (PEFR) measurements and their PEFR thresholds for seeking medical care.
- Drug-drug interactions between PIs and certain medications may affect treatment.
- Asthma is a chronic inflammatory disorder of the airways that causes recurrent episodes of wheezing, breathlessness, chest tightness, and cough, particularly at night and in the early morning.
- These symptoms are associated with airflow limitation that typically is reversible and responsive to bronchodilator therapy, unlike chronic obstructive pulmonary disease (see COPD).
- In asthma, airflow limitation is secondary to airway hyperresponsiveness and narrowing (increased resistance to flow) caused by inflammation and edema. In contrast, in COPD (particularly in the case of emphysema), airflow limitation is primarily caused by lung tissue destruction and loss of recoil, and is largely irreversible.
- Asthma is best distinguished from COPD (emphysema and chronic bronchitis) by clinical features such as:
- Marked variability in symptoms
- No history of cigarette smoking (although some asthmatics may smoke)
- Onset early in life (although asthma may present in adulthood)
- History of allergies such as hay fever
Because COPD may demonstrate partially reversible airflow obstruction, the response to a bronchodilator, particularly a single administration in the pulmonary function laboratory, may not reliably distinguish asthma and COPD.
- The prevalence of asthma in the United States is approximately 6-11%, depending on the population surveyed (higher prevalence among people living in the inner city).
- 75% of patients with asthma are diagnosed before the age of 7, although asthma may develop at any age.
- A small cross-sectional study of 83 HIV-infected children and young adults showed that 34% of the subjects carried a clinical diagnosis of asthma, and 42% were using rescue bronchodilators.
Veterans with HIV*
Clinical Signs and Symptoms
|History||Favoring diagnosis of asthma||Favoring other diagnosis (especially COPD)|
|Pulmonary function tests|
Pulmonary Function Testing
- Irreversible airflow obstruction: a post-bronchodilator forced expiratory volume in 1 second (FEV1) to forced vital capacity (FVC) ratio of <0.70 (note: may be less specific in older people).
- Reversible airflow obstruction: increase in post-bronchodilator FEV1 of ≥200 mL or >12% of predicted value.
- Partially reversible airflow obstruction: post-bronchodilator FEV1/FVC <70% of predicted value despite significant bronchodilator responsiveness.
- Spirometry: Measure FEV1, FVC, and bronchodilator response.
- PEFR: Measure brief, forceful exhalation on a peak flow meter. Peak flow meters are inexpensive, provide objective, reproducible assessments of airflow, and may be ordered through a facility's Prosthetics Service for home use by patients.
The test can be performed with the patient sitting or standing. Instruct the patient to breathe in maximally, put meter to mouth, seal lips around mouthpiece, and blow as hard and as fast as possible into meter.
- Record patients' personal best PEFR when they feel well and have had a number of good trials on the meter.
- Normal peak flow range is 80-100% of the personal best PEFR.
- Normal variability in PEFR is 15-20%. Unchanged PEFR in the presence of symptoms suggests a diagnosis other than asthma.
- Average PEFRs vary by age, sex, and height.
If initial pulmonary function test (PFT) results are normal or unobtainable, but asthma is still suspected:
- Have the patient record serial PEFR measurements and symptoms in a diary to determine whether there is evidence of intermittent airflow limitation that correlates with symptoms such as dyspnea, chest tightness, or cough.
- Repeat evaluation when patient is symptomatic.
- Consider performing serial measurements before and after bronchodilator treatment (this is helpful only if there is baseline airflow limitation at the time of testing).
- To diagnose occupational asthma, test before and after occupational exposures; this can be done with spirometry or PEFR. Taking repeated PEFR measurements and keeping a symptom diary are simple to do and may provide more useful information.
- Consider performing bronchoprovocation testing (methacholine or exercise challenge) for patients with atypical symptoms, such as chronic (rather than intermittent) cough or with normal baseline pulmonary function. Provocative testing should not be performed in patients who have typical asthma symptoms.
- ≤2 episodes/week of symptoms requiring treatment with short-acting beta-agonist (SABA) medication
- Prevent exacerbations and need for emergency department visits
- Minimize limitations on activity
- Minimize toxicities
- Patients with asthma who use tobacco should be counseled to stop. (see Smoking Cessation)
- At each visit, ask patients whether asthma has woken them from sleep, necessitated more rescue bronchodilator use than usual, necessitated urgent care or emergency room visits, or limited participation in usual activities.
- Ask about control of triggers.
- Provide an annual flu vaccination.
- Instruct patients to perform serial PEFR measurements at home and workplace.
- Determine each patient's baseline PEFR.
- Determine each patient's PEFR threshold and symptom threshold for escalating therapy or seeking medical evaluation; see Table 2. Patients should know their baseline PEFRs and their PEFR thresholds. Written plans based on symptoms or PEFR thresholds improve disease control.
- Review and instruct on correct use of inhalers with spacers. Patients who are unable to use spacers properly may need a nebulized formulation of a SABA.
- Use of SABA >2 times per week generally indicates inadequate chronic control and may necessitate a "step-up" in treatment. See below.
*There are important interactions between some inhaled corticosteroids and certain ARVs. See Table 4: Potential ARV Interactions.
|Mild Persistent||Step 2:|
|Moderate Persistent||Step 3:|
|Severe Persistent||Step 4:|
|When to Refer|
|Severity||Signs and Symptoms||Treatment|
|For acute symptoms and exacerbations|
|SABA (eg, albuterol, levalbuterol)|
|Anticholinergic bronchodilators (eg, ipratropium)|
|Systemic corticosteroids (prednisone or equivalent)|
|For long-term control|
|Inhaled corticosteroids (ICS); in order of increasing potency (on mg per mg basis):
|LABA (eg, formoterol, salmeterol)|
|Leukotriene receptor antagonists (eg, montelukast, zafirlukast)|
|Mast cell inhibitors (cromolyn, nedocromil)|
|For prevention of exercise-induced bronchospasm|
Long-Acting Beta Agonists
Leukotriene receptor antagonists
- Foster SB, Paul ME, Kozinetz CA, et al. Prevalence of asthma in children and young adults with HIV infection. J Allergy Clin Immunol. 2007 Mar;119(3):750-2.
- National Asthma Education and Prevention Program: Expert panel report III: Guidelines for the diagnosis and management of asthma. National Heart, Lung and Blood Institute; 2007. Accessed November 1, 2008.
- GINA: Global Strategy for Asthma Management and Prevention. Global Initiative for Asthma; 2009. Accessed November 23, 2010.
- VA/DoD Clinical Practice Guideline Working Group. Management of Asthma in Children and Adults. Washington, D.C.: Department of Veterans Affairs, Office of Quality and Performance; 2009. Accessed November 23, 2010.