Best Practices in Asthma: Beta-Agonists to Spirometry

Charles P. Vega, MD; Sandra G. Adams, MD, MS


April 25, 2017

Charles P. Vega, MD: Hello, and welcome to Critical Issues in Pulmonary Medicine. I am Chuck Vega, and I am a clinical professor of family medicine at the University of California at Irvine. Today, we are going to discuss asthma diagnosis. To do so, I am delighted to be joined by Dr Sandra Adams, who is a professor of medicine and a pulmonary and critical care specialist at University of Texas (UT) Health in San Antonio.

Asthma Is 'Undertreated and Underrecognized'

Dr Vega: It has been clear for years that primary care physicians may underrecognize and undertreat asthma, and this can have serious consequences for patients, in terms of morbidity and even mortality. In a recent study[1] evaluating a screening process for asthma among children and adolescents, 15% of the study cohort were identified as having moderate or severe persistent asthma at baseline by their clinicians.

But just applying some simple clinical questions raised this rate from 15% to 47.9%. Adding spirometry raised the rate from 15% to 56.9%. Combining the questions and spirometry led to even more recognition of children who are clearly being undertreated and underrecognized for having more severe types of asthma.

However, there is another part of the story for asthma diagnosis because, as you know well, the natural history of asthma can vary from patient to patient and improve over time. That is why a study by Aaron and colleagues[2] got a lot of attention. It demonstrated that approximately one third of adults diagnosed with asthma over the previous 5 years did not qualify for the diagnosis of asthma on repeat testing. They were diagnosed in the clinics, but had no evidence of asthma on formal testing by the researchers. These patients were followed over 1 year without medications, and the vast majority did fine with zero asthma treatment and regular follow-up.

This makes me wonder about best practices for the diagnosis of asthma. One of the first tools I think of is spirometry. Generally, it remains underused, and it is a must. Any thoughts on best practices for using spirometry in the diagnosis of asthma?

Spirometry 'Is Critical'

Sandra G. Adams, MD, MS: It is critical, because many things can cause symptoms similar to those of asthma: wheezing, shortness of breath, even cough. It is critical to have spirometry and make sure that you are not dealing with one of the other conditions.

If it absolutely looks like asthma and sounds like asthma, do spirometry. If [results are] normal, then you want to make sure and do the bronchodilator challenge with the spirometry. If those numbers improve and get even better, even though [results are] normal, then the diagnosis of asthma is very much supported.

Dr Vega: I order spirometry for everybody I suspect of having asthma. When I am doing my original order, should I always order a pre- and postbronchodilator? Is this best practice? Or should I be thinking that, in the situation where basic spirometry study is normal, then I do not need to worry about the bronchodilator?

Dr Adams: No; the way you are doing it is absolutely correct. I think everybody should be ordering pre- and postbronchodilator spirometry. It is just the practice of many pulmonary labs, and it depends on the director. If the spirometry is normal, many of them will not do the postbronchodilator even if you ordered it, unless you specify "administer even if normal." It will differ from center to center.

Challenge Testing

Dr Vega: When do you use challenge testing? That is something that I rarely do. Should I be thinking more of using either mannitol or methacholine to get specific detail on these exams?

Dr Adams: If somebody has a significant bronchodilator response, meaning an FEV1 or forced vital capacity improvement of 12% and 200 mL after administering bronchodilators, then it is probably not necessary to do a methacholine or mannitol challenge. The key is, if you do not have a diagnosis and it really sounds like asthma, then a methacholine challenge can be very helpful. It does not absolutely rule in the diagnosis. But if it is negative, it helps rule it out.

Eosinophil Measurement

Dr Vega: Great. That is really helpful.

What about eosinophils? A number of research studies have come out about measuring eosinophils either in the sputum[3] or in the serum.[4] How should that apply to primary care in the management of asthma?

Dr Adams: For the average person with asthma, it is probably not going to be that helpful. Sputum eosinophils should be measured in a specialized lab, so they are really only useful for research. However, serum eosinophils may be helpful before we do changes in therapy, especially in patients having exacerbations. A severe exacerbation or very high serum eosinophil values are risk factors that indicate that the patients with asthma may not be doing as well as if the serum eosinophils are low.

In addition, if you have somebody on therapy with a significant bronchodilator response (even on therapy) and serum eosinophils who is telling you, "My asthma is great," you have to take that with a grain of salt and realize that the asthma may not be as well-controlled as you think.

Step-Down Therapy

Dr Vega: That is a great segue into the next subject I want to discuss, which is step-down therapy. Aaron and colleagues' study suggested that we might actually be overtreating patients. Patients were treated up to moderate or even severe levels of asthma, but a few years later were not at that level of asthma and were receiving an inappropriately high number of drugs or intensity of therapy.

The guidelines suggest that we can step-down therapy within 3 months of patients achieving control, which seems pretty fast to me. What is your best practice for stepping down therapy among adults with control of asthma?

Dr Adams: That is a really good point. In San Antonio, we say "strike three and you're out." When we talked about the rule of twos, our students could not figure out that more than two is three. The "strike three rule" is, if you use a short-acting beta agonist inhaler for symptoms three times in a week, or wake up with asthma symptoms three nights in a month, or use three canisters of short-acting beta agonists in a year, you have persistent asthma. Those patients should be started on controllers. It is possible to go ahead and step down the therapy if they are not too symptomatic and after controlled for 3 months—especially if those 3 months include winter or spring, with all the allergens.

A lot of clinicians think that step-up therapy is kind of a one-way up escalator with no way down. It is really important for us to try to take patients and step them down when it is appropriate. If a patient has had severe symptoms, is poorly controlled, had a hospitalization, or has such things as significant bronchodilator response with persistent serum eosinophils, step-down might take longer, like 6 months.

The other key is, if you really want to step patients down safely, then you should follow them up quickly. You do not want to leave them for 3 or 6 months without follow-up. If possible, I typically follow them in 4-8 weeks. I get repeat spirometry and make sure that their bronchodilator response has not come back, their symptoms have not come back, and then potentially step them down all the way off of therapy. You are right—like many of the patients in Aaron and colleagues' study, not everybody with asthma needs to be on therapy for the rest of their life.

When Patients Rely on Beta-Agonists

Dr Vega: That is a great point. Now I am going to ask you a wild-card question about asthma devices.

I have noticed among patients with moderate to severe asthma that there is something of a psychological reliance on short-acting beta agonists. Even when they are on their controller medication, their peak flows are doing better, their spirometry is improved, and you go through a formal checklist and their nighttime and exercise symptoms are actually better, they are still using albuterol three or four times a day. When I ask them why, they say, "I felt like I was getting a cough, and I do not want to go into an exacerbation."

I have seen this multiple times now, and it is a little befuddling. There is always a potential for harm here. Have you seen this? Do you have any advice on how to gently guide these patients to the fact that the inhaler is truly for rescue and that they do not need to use it as frequently as they are?

Dr Adams: A lot of patients think that managing asthma is kind of like staying ahead of pain—like how you want to make sure somebody with pain after surgery takes their pain medicine regularly so that it does not get out of control. Patients with asthma have in their head that they need to keep the albuterol or short-acting beta-agonist on board so they do not develop symptoms.

I explain that a short-acting agent is like a "quick fix." If you take it regularly when you [do not] need it, it is not going to work as well because of downregulation of the receptors. This does not seem happen with the long-acting agents. That is what I really try to convince them. You need the controllers for the inflammation. You need to take them appropriately, and you really should not take the short-acting agent unless you need it. When you need it, take it. If you do not need it, do not assume that you are going to need it.

The one caveat is exercise. If you have exercise-induced asthma, you do want to go ahead and take either the short-acting or whatever agent it is controlling it before you exercise.

Dr Vega: Absolutely. Those are all points well-taken. This is a great way to step to our next topic of discussion, which is the use of inhaled medications.

Sandra, thanks very much. This was highly valuable.


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