Medical Policy: 02.01.48 

Original Effective Date: May 2012 

Reviewed: February 2018 

Revised: February 2016 


Benefit Application:

Benefit determinations are based on the applicable contract language in effect at the time the services were rendered. Exclusions, limitations or exceptions may apply. Benefits may vary based on contract, and individual member benefits must be verified. Wellmark determines medical necessity only if the benefit exists and no contract exclusions are applicable. This medical policy may not apply to FEP. Benefits are determined by the Federal Employee Program.


This Medical Policy document describes the status of medical technology at the time the document was developed. Since that time, new technology may have emerged or new medical literature may have been published. This Medical Policy will be reviewed regularly and be updated as scientific and medical literature becomes available.



Current techniques for diagnosing and monitoring asthma and predicting exacerbations are peak flow measurement and spirometry. Two new strategies, evaluation of exhaled nitric oxide (NO) and exhaled breath condensate are proposed. These techniques are also potentially useful in the management of other conditions such as chronic obstructive pulmonary disease (COPD) and chronic cough. There are commercially available devices for measuring NO in expired breath and various laboratory techniques for evaluating components of exhaled breath condensate.


Guidelines for the management of persistent asthma stress the importance of long-term suppression of inflammation using steroids, leukotriene inhibitors, or other anti-inflammatory drugs. Existing techniques for monitoring the status of underlying inflammation have focused on bronchoscopy, with lavage and biopsy, or analysis by induced sputum. Current standards in the assessment of asthma focuses not on the status of the underlying chronic inflammation, but rather on regular assessments of respiratory parameters such as forced expiratory volume in one second (FEV1) and peak flow. There has been interest in noninvasive techniques to assess the underlying pathogenic chronic inflammation as reflected by measurements of inflammatory mediators. Two proposed strategies are the measurement of exhaled nitric oxide (NO) and the evaluation of exhaled breath condensate.


Exhaled nitric oxide (NO)

Nitric oxide is an important endogenous messenger and inflammatory mediator that is widespread in the human body, functioning, for example, to regulate peripheral blood flow, platelet function, immune reactions, and neurotransmission and to mediate inflammation. In biologic tissues, NO is unstable, limiting measurement. However, in the gas phase, NO is fairly stable, permitting its measurement in exhaled air. Exhaled NO is typically measured during single breath exhalations. First, the subject inspires nitric oxide-free air via a mouthpiece until total lung capacity is achieved, followed immediately by exhalation through the mouthpiece into the measuring device. Several devices measuring exhaled NO are commercially available in the United States. According to a 2009 joint statement by the American Thoracic Society (ATS) and European Respiratory Society (ERS), there is a consensus that the fractional concentration of exhaled nitric oxide (FeNO) is best measured at an exhaled rate of 50 mL per second (FeNO 50 mL/s) maintained within 10% for more than 6 seconds at an oral pressure between 5 and 20 cm H2O. (1) Results are expressed as the NO concentration in parts per billion (ppb), based on the mean of 2 or 3 values.


Exhaled breath condensate (EBC)

Exhaled breath condensate (EBC) consists of exhaled air passed through a condensing or cooling apparatus, resulting in an accumulation of fluid. Although EBC is primarily derived from water vapor, it also contains aerosol particles or respiratory fluid droplets, which in turn contain various nonvolatile inflammatory mediators, such as cytokines, leukotrienes, oxidants, antioxidants, and various other markers of oxidative stress. There are a variety of laboratory techniques to measure the components of EBC, including such simple techniques as pH measurement, to the more sophisticated gas chromatography/mass spectrometry or high performance liquid chromatography, depending on the component of interest.


Measurement of NO and EBC has been investigated in the diagnosis and management of asthma. Potential uses in management of asthma include assessing response to anti-inflammatory treatment, monitoring compliance with treatment, and predicting exacerbations. Aside from asthma, they have also been proposed in the management of patients with chronic obstructive pulmonary disease (COPD), cystic fibrosis, allergic rhinitis, and primary ciliary dyskinesia.


The following devices/systems have been cleared for marketing by the FDA:

  • The NIOX Breath Nitric Oxide Test System® (Aerocrine AB, San Diego, CA) received 510(K) approval on April 30, 2003.
  • The NIOX MINO® (Aerocrine AB, Washington D.C) received 510(K) approval on March 3, 2008.
  • The Apieron INSIGHT eNO System received 510(K) approval on March 14, 2008.


The RTube Exhaled Breath Condensate collection system (Respiratory Research, Inc) is registered with the FDA as a Class I device that collects expired gas. Respiratory Research has a proprietary gas-standardized pH assay, which, when performed by the company, is considered a laboratory-developed test.


American Thoracic Society (ATS)/European Respiratory Society (ERS)

The ATS/ERS statement includes the following recommendations regarding use of biomarkers in clinical practice:

  • Where possible, biomarkers should be employed to provide information about underlying airway inflammation, a domain of the asthma ‘‘syndrome’’ that would not otherwise be available to the clinician
  • FENO measurements may be used as a surrogate marker for eosinophilic airway inflammation. They may be used to evaluate the potential for response to corticosteroid treatment.
  • Low values of FENO (< 25 ppb in adults, < 20 ppb in children) may be of particular value in aiding decisions about reducing corticosteroid dose, or alternatively for determining that ongoing airway symptoms are well managed.


The authors acknowledge that more information is required on the utility of FENO measurement as a tool for monitoring asthma control, and that there is a need for translational research to clarify the relationship between biomarkers and other parameters of asthma control, to establish the optimal frequency of monitoring, and to confirm the clinical and cost effectiveness of biomarker measurements in primary care and other settings.


Regarding exhaled breath condensate, the statement concludes that more work is needed on the validation of the various measures from EBC, and to describe the relationship between these measures and other markers of asthma control. The authors concluded that studies to address whether using EBC results in improved clinical decision-making or better asthma outcomes are required.


The accuracy of the cutoffs recommended by the American Thoracic Society (ATS) guidelines has not been evaluated in the diagnosis of asthma. In addition, no studies were identified that evaluated whether the use of FENO improved the accuracy of asthma diagnosis compared with clinical diagnosis. Given these limitations, it is not possible to evaluate whether the use of FENO levels in clinical practice improves the accuracy of diagnosing asthma.


Global Initiative for Asthma (GINA, 2012)

Guidelines from the Global Initiative for Asthma state that levels of FENO and carbon monoxide have been suggested as non-invasive markers of airway inflammation in asthma. The guidelines state that levels of FENO are elevated in people with asthma (who are not taking inhaled glucocorticosteroids) compared to people without asthma, yet these findings are not specific for asthma. The guidelines note the FENO has not been evaluated prospectively as an aid in asthma diagnosis, but these measurements are being evaluated for potential use in determining optimal treatment, "although it has been shown that the use of FENO as a measure of asthma control does not improve control or enable reduction in dose of inhaled glucocorticosteroid." The Global Initiative for Asthma was launched in conjunction with the National Heart Lung and Blood Institute and the World Health Organization.


American Academy of Pediatrics

A statement by the American Academy of Pediatrics Section on Allergy and Immunology noted that some specialists may consider evaluation of airway inflammation by using FENO to be useful, but concluded that the value of additional FENO monitoring in children whose asthma is appropriately managed using guideline-based strategies is unproven.


While FENO levels generally predict which patients will respond to inhaled glucocorticoid therapy,the largest trials and a systematic review did not find sufficient evidence to support routine use of FENO to guide asthma therapy.


Prior Approval:

Not applicable



Measurement of exhaled nitric oxide is considered investigational in the diagnosis and management of asthma and all other disorders including but not limited to chronic obstructive pulmonary disease and chronic cough.


Measurement of exhaled breath condensate is considered investigational in the diagnosis and management of asthma and all other disorders including but not limited to chronic obstructive pulmonary disease and chronic cough.


The evidence is insufficient to determine the effect of exhaled nitric oxide and exhaled breath condensate tests on health outcomes. The recent studies do prove that there is treatment change with the addition of FENO measurements, but fail to examine the effect of the treatment changes on outcomes. There is still no validated standardized cutoff of FENO to use for diagnosing asthma. As a result, it is not possible to determine the true sensitivity and specificity of the test for diagnosing asthma or any other disorder. Further investigation is recommended because a negative result does not exclude asthma. Inhaled steroids are a mainstay of treatment of asthma and have been associated with a variety of health outcome benefits. The change in management must be examined to determine net benefits on health outcomes. Recent systematic review concluded FENO guided management showed no statistically significant benefit in terms of severe exacerbations or ICS use, but showed a statistically significant reduction in exacerbations of any severity. However, further research is warranted to clearly define which management protocols (including cut-off points) offer best efficacy and which patient groups would benefit the most.


Procedure Codes and Billing Guidelines:

  • To report provider services, use appropriate CPT* codes, Modifiers, Alpha Numeric (HCPCS level 2) codes, Revenue codes, and/or diagnosis codes.
  • 95012 Nitric oxide expired gas determination
  • 83987 pH; exhaled breath condensate


Selected References:

  • Petsky HL, Cates CJ, Li A, Kynaston JA, et al. Tailored interventions based on exhaled nitric oxide versus clinical symptoms for asthma in children and adults. Cochrane Database Syst Rev. 2009 Oct 7; (4):CD006340.
  • Petsky HL, Cates CJ, Lasserson TJ, Li AM, et al. A systematic review and meta-analysis: tailoring asthma treatment on eosinophilic markers (exhaled nitric oxide or sputum eosinophils). Thorax. 2012 Mar; 67(3):199-208.
  • Gibson, PG. Using fractional exhaled nitric oxide to guide asthma therapy: design and methodological issues for Asthma Treatment Algorithm studies. Clin Exp Allergy. 2009 Apr; 39(4):478-90.
  • de Jongste JC, Carraro S, Hop WC, Baraldi E; CHARISM Study Group. Daily telemonitoring of exhaled nitric oxide and symptoms in the treatment of childhood asthma. Am J Respir Crit Care Med. 2009 Jan 15; 179(2):93-7.
  • Sachs-Olsen C, Lodrup Carlsen KC, Mowinckel P, Haland G, et al. Diagnostic value of exhaled nitric oxide in childhood asthma and allergy. Pediatr Allergy Immunol. 2010 Feb; 21(1 Pt 2): e213-21.
  • McCurdy MR, Wazni MW, Martinez J, et al. Exhaled nitric oxide predicts radiation pneumonitis in esophageal and lung cancer patients receiving thoracic radiation. Radiother Oncol. 2011 Dec; 101(3):443-8.
  • Powell H, Murphy VE, Taylor DR, Hensley MJ, et al. Management of asthma in pregnancy guided by measurement of fraction of exhaled nitric oxide: a double-blind, randomized controlled trial. Lancet. 2011 Sep 10; 378(9795):983-90.
  • Dweik RA, Boggs PB, Erzurum SC, Irvin CG, et al. An official ATC clinical practice guideline: interpretation of exhaled nitric oxide levels (FENO) for clinical applications. Am J Respir Crit Care Med. 2011 Sep 1; 184(5):602-15.
  • Yates DH, Krishnan A, Chow S, Thomas PS. Non-invasive assessment of exhaled biomarkers in lung transplantation. J Breath Res. 2011 Jun; 5(2):024001.
  • Reddel HK, Taylor DR, Bateman ED, et al. An Official American Thoracic Society/European Respiratory Society Statement: Asthma Control and Exacerbations. Standardizing Endpoints for Clinical Asthma Trials and Clinical Practice. Am J Respir Crit Care Med. 2009 Jul 1; 180(1):59-99.
  • ECRI Institute. Exhaled Nitric Oxide for Diagnosing and Monitoring Asthma. Plymouth Meeting (PA): ECRI Institute's Health Technology Assessment Information Service 2011 Apr 4. [Hotline Response].
  • Larsson, K. Inflammatory markers in COPD. Clin Respir J. 2008 Oct; 2 Suppl 1: 84-7.
  • Kazani, S & Israel, E. Exhaled breath condensates in asthma: diagnostic and therapeutic implications. J Breath Res. 2010 Dec; 4(4):047001.
  • Pike A. et al. Exhaled nitric oxide monitoring does not reduce exacerbation frequency or inhaled corticosteroid dose in pediatric asthma: Clinical Respiratory Hournal 2013; 204-213.
  • Syk J, Malinovschi A, Johansson G et al. Anti-inflammatory Treatment of Atopic Asthma Guided by Exhaled Nitric Oxide: A Randomized, Controlled Trial. J Allergy Clin Immunol 2013; 1(6):639-48.e8.
  • Peirsman EJ, Carvelli TJ, Hage PY et al. Exhaled nitric oxide in childhood allergic asthma management a randomised controlled trial. Pediatr Pulmonol 2013
  • Thomas PS, Lowe AJ, Samarasinghe P et al. Exhaled breath condensate in pediatric asthma: promising new advance or pouring cold water on a lot of hot air? a systematic review. Pediatr Pulmonol 2013; 48(5):419-42.
  • Raj D, et al. Fractional exhaled nitric oxide (FENO) in children with acute exacerbation of asthma. Indian Pediatr 2013 Sep 5 [Epub ahead of print].
  • McCormack MC, et al. Guideline-recommended fractional exhaled nitric oxide is a poor predictor of health-care use among inner-city children and adolescents receiving usual asthma care. Chest 2013 Sep;144(3):923-9.
  • National Institutes of Health (NIH) 2007 NAEPP EPR-3. National Asthma Education and Prevention Program Expert Panel Report 3
  • LaForce C, Brooks E, Herje N et al. Impact of exhaled nitric oxide measurements on treatment decisions in an asthma specialty clinic. Ann Allergy Asthma Immunol (2014) 1-5.
  • R.A. Dweik, P.B. Boggs, S.C. Erzurum, C.G. Irvin, M.W. Leigh, J.O. Lundberg, et al. An official ATS clinical practice guideline: interpretation of exhaled nitric oxide levels (FENO) for clinical applications Am J Respir Crit Care Med, 184 (2011), pp. 602–615.
  • Voorend A, Vaessen A. et al. Fractional Exhaled Nitric Oxide Monitoring Does Not Improve Asthma Management in Children with Concordant and Discordant Asthma Phenotypes
  • Navratil M, Plavec D, Bulat Lokas S, et al. Urates in exhaled breath condensate as a biomarker of control in childhood asthma. J Asthma. Nov 11 2014:1-37. PMID 25387148
  • Honkoop PJ, Loijmans RJ, Termeer EH, et al. Symptom- and fraction of exhaled nitric oxide-driven strategies for asthma control: A cluster-randomized trial in primary care. J Allergy Clin Immunol. Aug 28 2014. PMID 25174865
  • Wilson E, McKeever T, Hargadon B, et al. Exhaled nitric oxide and inhaled corticosteroid dose reduction in asthma: a cohort study. Eur Respir J. Aug 19 2014. PMID 25142486
  • Lee QU. Fractional exhaled nitric oxide-guided algorithm for children with asthma. Pediatr Pulmonol. 2015;50(9):932-933.
  • Hoffmeyer F, van Kampen V, Deckert A, et al. Evaluation of airway inflammation in compost workers exposed to bioaerosols using exhaled breath condensate and fractional exhaled nitric oxide. Adv Exp Med Biol. 2015 Mar 19 [Epub ahead of print].
  • Szefler SJ, Mitchell H, Sorkness CA, et al. Management of asthma based on exhaled nitric oxide in addition to guideline-based treatment for inner-city adolescents and young adults: a randomised controlled trial. Lancet 2008; 372:1065.
  • Calhoun WJ, Ameredes BT, King TS, et al. Comparison of physician-, biomarker-, and symptom-based strategies for adjustment of inhaled corticosteroid therapy in adults with asthma: the BASALT randomized controlled trial. JAMA 2012; 308:987.
  • Shaw DE, Berry MA, Thomas M, et al. The use of exhaled nitric oxide to guide asthma management: a randomized controlled trial. Am J Respir Crit Care Med 2007; 176:231.
  • Guo Z, Wang Y, Xing G, et al. Diagnostic accuracy of fractional exhaled nitric oxide in asthma: a systematic review and meta-analysis of prospective studies. J Asthma. May 2016;53(4):404-412. PMID 26796787
  • Li Z, Qin W, Li L, et al. Diagnostic accuracy of exhaled nitric oxide in asthma: a meta-analysis of 4,691 participants. Int J Clin Exp Med. 2015;8(6):8516-8524. PMID 26309503
  • Munira Essat, Sue Harnan, Tim Gomersall, Paul Tappenden, Ruth Wong, Ian Pavord, Rod Lawson, Mark L. Everard   Fractional exhaled nitric oxide for the management of asthma in adults: a systematic review. European Respiratory Journal  2016;  DOI: 10.1183/13993003.01882-2015
  • Dinaker, C., Chipps, B. Clinical tools to assess asthma control in children. American Academy of Pediatrics 2017, 139 doi: 10.1542/peds.2016-3438. 
  • Carpagnano GE, Foschino-Barbaro MP, Crocetta C, et al. Validation of the exhaled breath temperature measure: Reference values in healthy subjects. Chest. 2017;151(4):855-860.
  • Guilleminault L, Saint-Hilaire A, Favelle O, et al. Can exhaled nitric oxide differentiate causes of pulmonary fibrosis? Respir Med. Nov 2013;107(11):1789-1796. PMID 24011803
  • Harnan SE, Essat M, Gomersall T, et al. Exhaled nitric oxide in the diagnosis of asthma in adults: a systematic review. Clin Exp Allergy. Mar 2017;47(3):410-429. PMID 27906490
  • Peel AM, Crossman-Barnes CJ, Tang J, et al. Biomarkers in adult asthma: a systematic review of 8-isoprostane in exhaled breath condensate. J Breath Res. 2017;11(1):016011.
  • Karrasch S, Linde K, Rucker G, et al. Accuracy of FENO for diagnosing asthma: a systematic review. Thorax. Feb 2017;72(2):109-116. PMID 27388487


Policy History:

  • February 2018 - Annual Review, Policy Renewed
  • February 2017 - Annual Review, Policy Renewed
  • February 2016 - Annual Review, Policy Revised
  • March 2015 - Annual Review, Policy Revised
  • April 2014 - Annual Review, Policy Renewed
  • May 2013 - Annual Review, Policy Renewed
  • May 2012 - New Policy

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