The Aeriflux™ Breath Test helps determine objectively when airway acid causes cough.

Professional > Frequently Asked Questions

Frequently Asked Questions

1. When is Aeriflux indicated?

2. How does my patient collect samples?

3. What if my patient only has coughing episodes every few days?

4. Please tell me about the effect that eating or drinking may have on the Aeriflux™ test.

5. How can my patients know if they are providing enough breath sample for the assay?

6. What if I, as a doctor or health care practitioner am interested in something other than cough in my patients.

7. How should I use Aeriflux™ in the management of my patients with underlying asthma or COPD?

8. How do we get reimbursed for Aeriflux?

9. What about lower esophageal acid reflux? Is it relevant to acid reflux cough through a reflex pathway?

10. How can I get Aeriflux testing performed on my patient?

1. When is Aeriflux™ indicated?
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Aeriflux™ is indicated to support the diagnosis of acid reflux as a contributor to chronic cough, and to determine the likelihood that a patient will respond to therapy with Proton Pump Inhibitor medications. Always use in conjunction with patient history and physical exam.

2. How does my patient collect samples?
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Patients should review the written instructions that accompany the Aeriflux™ sample collection kit. They are asked to collect six 5-minute samples over 1-3 days. If there are additional questions after reviewing this document, please contact Respiratory Research directly by emailing info@respiratoryresearch.com

3. What if my patient only has coughing episodes every few days?
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Your patients can take as many days as they need to do collect the six "cough" samples requested for the Aeriflux™ Exhaled Breath Condensate pH Test. However, the Aeriflux™ test will be of the most benefit to your frequently coughing patients.

4. Please tell me about the effect that eating or drinking may have on the Aeriflux™ test.
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The patient should NOT eat or drink anything but water for one hour prior to a collection. This can make the sampling more difficult, but it is necessary to assure that acids in food that your patient may eat or drink do not cause a false result by making their saliva temporarily acidic. In our testing, after drinking acidic fluids, the Aeriflux™ test may be falsely positive for up to 20 minutes. The requirement to avoid eating or drinking for one hour before collection is to make doubly sure that this cannot affect the assay.

5. How can my patients know if they are providing enough breath sample for the assay?
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There are several helpful hints to tell your patients. We ask that you tell them the following:
a. Put some effort into the breath sampling. We don’t want the patient hyperventilating, but DO want him/her to breathe through the RTube™ collector with the type of effort he/she might use in playing a trumpet or clarinet. They should push the air out of their lungs with a bit more effort than usual. They should NOT breathe very calmly as one does when watching TV. More effective is to breathe with a bit of extra flow.
b. Make sure the patient performs the sample collection for at least the full 5 minutes. It is totally acceptable to do the sample collection for longer. But not less than 5 minutes.
c. If you know or suspect that your patient has very poor lung function (less than 40% of their predicted FEV1), it is wise to ask them to spend 10 to 12 minutes breathing through the Aeriflux breath sample collector for each collection.
d. Your patients should not breathe through their nose when they perform the breath collections. Just through their mouth.

6. What if I, as a doctor or health care practitioner am interested in something other than cough in my patients.
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Aeriflux™ has been validated for its use in diagnosing if acid reflux is contributing to cough. Acid reflux can also cause wheezing, shortness of breath, hoarse voice, and other problems (including pneumonia, sinusitis and ear infections). Sometimes, acid reflux can cause lung damage even without cough (nerves in the lung that sense acid can be down-regulated or desensitized in some patients). All these issues potentially warrant investigation by Aeriflux™, however we do not promote Aeriflux™ for these purposes as yet as the data are not sufficient to know how accurate the test is for symptoms other than cough. Note that cough by itself, or cough as a symptom of asthma, emphysema and other respiratory diseases can be assessed by Aeriflux™.

7. How should I use Aeriflux™ in the management of my patients with underlying asthma or COPD?
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This patient group consumes the majority of the financial resources devoted to asthma. The diagnosis of severe asthma is difficult because there are so many contributors and mimics to the condition. Patients with severe asthma are by their nature harder to manage with standard therapeutic modalities such as inhaled steroids, and more likely to have confounding diagnoses such as vocal cord dysfunction or acid reflux.

At what point acid reflux enters into your thinking depends on the patient and your practice style. Here are some considerations which might prompt you to consider Acid Reflux as a potential and important problem in many of your patients with underlying lung disease

--Acid reflux occurs in over 50% of severe asthmatics and COPD patients, and is a likely contributor to respiratory symptoms in most of these.

--Esophageal symptoms such as heartburn are often not present. It takes very little acid in the airway to cause cough. But this mild acid reflux may well be insufficient to cause any heartburn.

--Symptomatic gastroesophageal reflux disease (GERD) and heartburn may be present in some patients with asthma without being relevant to their respiratory symptoms.

--Just because a patient has heartburn does not mean it is causing the cough. Likewise, patients can have acid reflux cough without any symptoms of GERD.

--Esophageal pH probes are located in the wrong place to identify airway acidification, trigger coughing on their own by physical stimuli, and importantly suffer from inappropriate interpretation. It makes sense that it is airway acidification that is most important to evaluate in people who have acid reflux exacerbating their asthma. The airway is not the esophagus, and tiny amounts of acid reflux that are considered “normal” by esophageal pH probe guidelines can be highly relevant and abnormal for the acid-intolerant airway.

Determining to what extent acid reflux is confounding pathologic processes and contributing to the underlying lung disease symptomatology is difficult. As noted above, esophageal pH probes are not the best diagnostic tool for acid reflux induced respiratory symptoms in most patients. Therapeutic trials of proton pump inhibition are commonly used instead. However, these trials suffer from the following limitations:

--Require patient adherence/compliance to be accurate.

--Provide little confidence that acid reflux is assuredly important:
If a patient does not get better, it may result from failure of adherence, or a concomitant exacerbating factor (entering allergy season, infection with the common cold).

--If a patient does get better, the improvement may result from placebo effect, or from decreasing concomitant factors, such as exiting allergy season, or spontaneous resolution of symptoms for other reasons.
--Require up to 3 months to adequately complete the therapeutic trial.

--The lack of specificity of a therapeutic trial causes patients to be left on unnecessary and potentially multi-year treatment with expensive proton pump inhibitors.

--The rebound hyperacidification that occurs when stopping PPI medications can lead to esophageal reflux symptoms which can reinforce the initial incorrect diagnosis of acid reflux cough.

Aeriflux™ overcomes these issues by providing objective evidence of acidification in the airway occurring in association with cough. Obtaining these diagnostic data requires no long-term medication, provides straightforward chemical evidence about whether acid reflux is important in this patient.

Aeriflux testing is a recommended component of the evaluation of patients who have a reasonable likelihood of having acid reflux contributing to their illness, including:

--Chronic cough persisting more than 4 weeks without improvement

--Chronic obstructive pulmonary disease with cough and/or wheeze, not sufficiently responsive to usual therapies

--Asthma with cough/wheeze, not sufficiently responsive to usual dosages of appropriate medications

--Asthma exacerbation requiring admission to hospital or emergency visit

--COPD exacerbation requiring admission to hospital or emergency visit

--Recurrent laryngospasm

--Vocal Cord Dysfunction

--Underlying respiratory disease that is difficult to treat and for which confounding acid reflux as a cause of symptoms should be sought. For example - refractory COPD, severe asthma, pulmonary fibrosis/interstitial lung disease, cystic fibrosis, lung transplant recipient, and others.

--Respiratory symptoms in the setting of a high incidence of acid reflux.

Each doctor needs to make the determination of how valuable Aeriflux testing may be in a given setting.

8. How do we get reimbursed for Aeriflux?
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Please see Reimbursement Page.

9. What about lower esophageal acid reflux? Is it relevant to acid reflux cough through a reflex pathway?
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It is clear that there is a vagal nerve mediated esophageal – airway reflex path that can be activated by lower esophageal acid exposure. This can also trigger neurogenic inflammation. A large amount of acid is required for this reflex to activate. Note that drinking lemonade, which acidifies the esophagus, does not cause cough unless it is aspirated. Also, despite frequent and excessive acid in the esophagus, most people with GERD do not have chronic cough.

Acid can be aspirated into the lung. Even microliters of acid entering the airway causes injury and elicits reflexive cough in part mediated by vagal nerves of the airway.

So, yes, there is a described pathway for lower esophageal acid to trigger cough. But it is the tiny amounts of acid that get to the larynx or into the lower airway that are most important by far. And Aeriflux™ is the straightforward way to find that acid, and is non-invasive and easy for the patient.

10. How can I get Aeriflux testing performed on my patient?
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Simply order this test from your local authorized laboratory as you would any other. The lab will provide the breath specimen collection kit to you or directly to your patient, and will pick up the collected specimens. Once the breath specimens have been tested, you will receive a report of results from your laboratory. In case no laboratories in your area currently offer this test, please contact us and we will work with them to make the test available to your practice.

If you have other questions, please email:
info@respiratoryresearch.com

We will be happy to help.

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