This document provides information about exhaled nitric oxide (eNO) testing for asthma management. It discusses the burden of asthma, the role of airway inflammation, and how eNO can be safely and accurately measured as a marker of inflammation. eNO levels correlate with other inflammation measures and change with treatment. Clinical guidelines recommend eNO monitoring to help adjust medications and control symptoms. The goal is improving outcomes by optimizing treatment of underlying inflammation.

1. Advancing Asthma
Management with
Exhaled Nitric Oxide
RESOURCE KIT

2. Table of Contents
Summary 2
1 The Burden of Asthma 3
2 Exhaled Nitric Oxide (eNO) 4
3 Insight™ eNO System 6
4 Case Studies 9
5 Exhaled Nitric Oxide Cost Model 12
6 Coding Information for Exhaled Nitric
Oxide (eNO)-CPT 95012 12
Summary Clinical Utility of eNO
Exhaled nitric oxide (eNO) is an established marker of airway Monitoring of eNO and adjusting medication accordingly could
inflammation that can be safely and accurately measured in significantly improve disease management, resulting in reduction
people with asthma. This resource kit provides comprehensive of the severity of symptoms, optimization of drug usage and
information about the benefits and technology of eNO testing, improvement of compliance in individual patients, and fewer
and highlights the medical necessity and the extent of acceptance exacerbations. The end result is optimal use of healthcare
of eNO testing. resources and improved quality of life for asthma patients.
The Asthma and Airway Inflammation Dilemma Reimbursement for eNO Testing
It is estimated that 22 million+ people in the U.S. suffer from asthma, In 2007 the CPT editorial committee added a specific code to
,
making it one of the most common and costly of all diseases. One the CPT Coding Book for Nitric Oxide Expired Gas Determination
quarter of all emergency room visits are asthma related and asthma (CPT Code 95012©). With this action, the procedure should be
is the one of the leading chronic childhood diseases. recognized as a standard service provided to patients. Exhaled
nitric oxide (eNO) determination is considered a service which is
Controlling inflammation of the airways has become the central
consistent with contemporary medical practice for the evaluation
focus for managing asthma. Strong clinical evidence suggests
of patients with respiratory complaints.
that asthma management and control can be significantly
improved by regularly monitoring airway inflammation. However,
current methods used to monitor and manage asthma, such as
Apieron and the Insight™ eNO System
lung function tests, do not measure airway inflammation. Apieron, Inc. is a medical device company based in Menlo Park,
California. The company was founded in 2001 to develop the
Physicians have relied largely on correlating symptoms and disease
first practical, office-based device for routine measurement of
severity to assess their patients. Until now, the degree of airway
exhaled nitric oxide. In March 2008, the company received FDA
inflammation has not been measurable in a simple and practical way.
510(k) clearance for the Insight™ eNO System, which is now
commercially available. Apieron’s goal is to offer a better way to
The eNO Solution manage asthma and improve the standard of care for patients
Exhaled nitric oxide has been established as a reliable marker of who live with the disease.
airway inflammation in asthma for over 10 years. It has been the
The Insight system is a highly accurate device, expressly
central focus of studies, establishing its link to optimization of
designed for the physician’s office to measure nitric oxide in
medication and prediction of asthma exacerbations.
expired human breath (eNO). It is non-invasive, safe, easy to
Measurement of eNO in the physician’s office is a much awaited use, and provides results in less than a minute. Apieron’s unique
breakthrough in medical technology that provides physicians with biosensor utilizes proprietary technology to detect trace amounts
a reliable tool to measure airway inflammation as an adjunct to of nitric oxide in a single human breath.
the current diagnostic measures, such as lung function.
2

3. 1. The Burden of Asthma considering the prevalence of asthma and the frequency of such
visits, as outlined in the statistics below, the costs become
Asthma Overview monumental.
Asthma is a chronic disease characterized by inflammation of the • 34.1 million people have been diagnosed with asthma during
airways caused by allergens and other triggers. When airways their lifetime.1
are inflamed, the inner walls of the airways swell making them • 22.8 million people have asthma.1
irregular. This causes the flow of air to become turbulent.
• There were 14.1 million outpatient asthma visits to private
The events that lead to obstruction of airflow and thus to asthma physician offices and hospital outpatient departments.2
symptoms are complex and usually involve the following events: • Children less than 18 years had 7 million physician office and
• Bronchoconstriction, where the smooth muscle surrounding the outpatient visits.3
airways tightens in response to a trigger and narrows the airway. Morbidity
• Inflammation, where inner walls of airways swell. • Asthma accounts for one quarter of all emergency room visits
• Mucus formation within the airways that obstructs airflow. in the U.S. each year, with 2 million emergency room visits.4
Typical asthma symptoms include wheezing, coughing, chest • Each year, asthma accounts for more than 1 million outpatient
tightness (dyspnea) and shortness of breath. visits4 and 500,000 hospitalizations.5
• The average length of stay (LOS) for asthma hospitalizations is
The Role of Inflammation in Asthma 3 days.6
Asthma signs and symptoms evolve from three basic • Nearly half (41%) of asthma-related hospitalizations are for
characteristics that underlie the disease and its exacerbations: children less than 19 years old.5
airway obstruction, airway hyperresponsiveness and airway
• Respiratory illnesses like asthma are the leading cause of
inflammation. Airway obstruction and hyperresponsiveness
hospitalization for children. 6
represent the classic physiology of asthma, and their contribution
to the disease process and symptomatology have been well Mortality
recognized for some time. Appreciation of the role of airway • There are about 4,000 deaths due to asthma each year, many
inflammation in asthma has evolved more recently. of which are avoidable with proper treatment and care.7
Today asthma experts consider airway inflammation a central Social and Economic Costs
feature of asthma pathogenesis and its clinical manifestations.
In fact, airway inflammation likely plays a critical role in airway • The annual cost of asthma is estimated to be nearly $18 billion.
obstruction and hyperresponsiveness. In recent years, clinical • Direct costs accounted for nearly $10 billion (hospitalizations
and scientific knowledge of asthma has evolved from a model the single largest portion of direct cost) and indirect costs of $8
of episodic constriction of bronchial smooth muscle to a model billion (lost earnings due to illness or death).8
which involves chronic airway inflammation. • For adults, asthma is one of the leading causes of work
Airway inflammation precedes symptoms. Evidence of absenteeism and “presenteeism, resulting in nearly 13 million
”
inflammation is present at the onset of symptoms in newly missed or lost (“less productive”) workdays each year.9
diagnosed patients with asthma. Accordingly, treatment • Among children ages 5 to 17 asthma is the leading cause
,
algorithms for asthma have emphasized treatment of the of school absences from a chronic illness. It accounts for an
underlying inflammation, as well as the bronchoconstrictive annual loss of more than 13 million school days per year.3 It is
symptoms. By acquiring a better understanding and appreciation estimated that children with asthma spend a nearly 8 million
of the inflammatory process, physicians can employ treatments days per year restricted to bed.8
to inhibit specific steps in the process and improve control over
asthma and its symptoms.
The Cost of Asthma
Asthma affects 22 million Americans. A principal clinical 1. “National Health Interview Survey, National Center for Health Statistics, CDC, 2006.
”
consequence of both acute and chronic inflammation is the 2. CDC: http://www.cdc.gov/nchs/fastats/asthma.htm - accessed on Sep 2, 2008.
development of asthma exacerbations. Exacerbations of 3. “State of childhood asthma in the United States, CDC,1980-2005.
”
asthma are not only an important clinical marker of inadequately 4. “National Hospital Ambulatory Medical Care Survey, CDC, 2001-2004.
”
controlled or worsening asthma but are probably the most
5. “National Hospital Discharge Survey, National Center for Health Statistics, CDC,
”
important outcomes from both a humanistic and health 2001-2004.
economics viewpoint. Severe asthma exacerbations lead to about 6. “National Health Statistics Survey, National Center for Health Statistics, CDC, 2006.
”
4,000 deaths and nearly 500,000 hospitalizations per year.
7 “National Vital Statistics Reports, Vol 56, Number 10, CDC, 2005.
. ”
Healthcare costs for asthma include outpatient visits to physician 8. “The Costs of Asthma, Asthma and Allergy Foundation 1992 and 1998 Study,
”
offices and hospital outpatient departments, visits to hospital 2000 Update.
emergency departments (EDs) and hospitalizations. When 9. “Asthma Prevalence, Health Care Use and Mortality, CDC, 2003-2005.
”
3

4. 2. Exhaled Nitric Oxide (eNO) effective local vasodilator. It causes smooth muscle relaxation
thereby matching regional airflow and blood flow. Nitric oxide is
Current Methods for Assessing Airway also important for ciliary action. Numerous studies over the past
decade have validated that exhaled nitric oxide (eNO) can serve as
Inflammation
a biomarker of airway inflammation in asthma.
Airway inflammation is shown to be an appropriate target for
In 1991, NO in exhaled breath was first reported.12 Studies have
improving asthma control10, and while it is recognized as playing
shown that eNO is correlated with other markers of inflammation.
a key role in the pathophysiology of asthma, current methods to
For example, exhaled nitric oxide correlates with eosonophilic
evaluate a patient’s asthma status fall short because they do not
airway inflammation measured in induced sputum13 and in
directly measure the degree of airway inflammation. Physicians
bronchoscopy (lavage and biopsy), most commonly seen in
attempt to monitor asthma severity through clinical exam and
asthma but also in any condition where eosonophils are present,
pulmonary function testing using spirometry or peak flow meters.
such as allergic rhinitis, eosonophilic bronchitis14 and chronic
Unfortunately, these lung function tests do not directly measure
obstructive pulmonary disease (COPD).15
airway inflammation. Other markers of inflammation such as
bronchoalveolar lavage and induced sputum are invasive and It has also been shown that eNO levels are elevated in steroid-
impractical to perform in a physician’s office. Therefore, when naive asthma,16 and eNO levels fall rapidly with anti-inflammatory
prescribing and titrating medication, physicians have had to rely medication (e.g. inhaled corticosteroids)17, oral steroids, anti-
on qualitative measures such as correlation of disease severity leukotrienes (e.g. montelukast)18 and anti-IgE (e.g. Xolair).19 Exhaled
and symptoms. Adding to this challenge is the fact that patients nitric oxide also correlates with non-specific bronchial reactivity
with severe asthma may have a compromised perception of to methacholine (typically assessed in methacholine challenge) in
airflow obstruction and dyspnea compared to normal individuals11 steroid-naïve patients. Increased reactivity is reflected by higher
and, thus, underestimate the severity of their symptoms. eNO levels and is an indirect marker of airway inflammation.
Without a convenient means to accurately and regularly assess It is now well established that the concentration of nitric oxide
inflammation, it is difficult for physicians to manage asthma. in exhaled breath (eNO) is a reliable indicator of the degree of
Inhaled corticosteroids (ICS) are the mainstay of treatment for inflammation in the airways. Exhaled nitric oxide levels increase as
chronic asthma, and dosing should be adequate to control asthma inflammation increases and decrease as inflammation decreases.
symptoms but also be as low as possible to avoid side effects.
Under-medication and over-medication are sub-optimal both Clinical Recommendations for eNO
clinically and economically. If not managed properly, people with
asthma could experience permanent and irreversible damage Clinical recommendations exist for use of eNO measurements in
to their airways. Since the dose of medication required is highly asthma management, and such recommendations are currently
variable, both among patients and within individual patients, being reviewed and updated:
physicians need an easy, effective and safe method to assist • The American Thoracic Society and European Respiratory
them with titrating medication precisely. Society (ATS/ERS) have published recommendations for the
The lack of knowing a patient’s degree of airway inflammation standardized measurement of eNO.20
creates a significant gap in asthma management today. With 12. Gustafsson LE, Leone AM, Persson MG, Wiklund NP Moncada S. Endogenous
,
direct markers of inflammation, this gap can be closed to improve nitric oxide is present in the exhaled air of rabbits, guinea pigs and humans.
Biochem Biophys Res Commun. 1991;181(2):852-857 .
the overall treatment and management of asthma. Insight into a
patient’s airway inflammation could enable physicians to make 13. Jatakanon A, Lim S, Kharitonov SA, Chung KF Barnes PJ. Correlation between
,
exhaled nitric oxide, sputum eosinophils, and methacholine responsiveness in
earlier interventions with appropriate levels of therapy, thereby
patients with mild asthma. Thorax 1998;53:91-95.
preventing emergency room visits and hospitalizations.
14. Berlyne GS, Parameswaran K, Kamada D, Efthimiadis A, Hargreave FE. A
comparison of exhaled nitric oxide and induced sputum as markers of airway
Exhaled Nitric Oxide (eNO) as a Biomarker of inflammation. J Allergy Clin Immunol 2000;106:638-644.
Airway Inflammation 15. Fabbri LM, Romagnoli M, Corbetta L, et al. Differences in airway inflammation
in patients with fixed airflow obstruction due to asthma or chronic obstructive
Nitric oxide (NO), a free radical, is produced by the body as part pulmonary disease. Am J Respir Crit Care Med 2003;167:418-424.
of the inflammatory response and can be detected as exhaled 16. Alving K, Weitzberg E, and Lundberg JM. Increased amount of nitric oxide in
nitric oxide in expired human breath. Nitric oxide is produced exhaled air of asthmatics. Eur Respir J. 1993;6(9):1368-1370.
in the airway epithelial cells by a family of NO synthases called 17 Yates DH, Kharitonov SA, Robbins RA, Thomas PS, Barnes PJ. Effect of a nitric
.
inducible nitric oxide synthase. Inducible NO synthase expression oxide synthase inhibitor and a glucocorticosteroid on exhaled nitric oxide. Am J
is sensitive to steroids and therefore shows a change in response Respir Crit Care Med. 1995;152(3):892-896.
to treatment with anti-inflammatory medication like inhaled 18. Bratton DL, Lanz MJ, Miyazawa N, White CW, Silkoff PE. Exhaled nitric oxide
steroids. Nitric oxide is a mediator of inflammation and it is an before and after montelukast sodium therapy in school-age children with chronic
asthma: A preliminary study. Pediatr Pulmonol 1999;28:402-407 .
10. Green RH, Brightling CE, McKenna S, Hargadon B, Parker D, Bradding P, 19. Silkoff PE, Romero FA, Gupta N, Townley RG, Milgrom H. Exhaled nitric oxide
Wardlaw AJ, Pavord ID. Asthma exacerbations and sputum eosinophil counts: A in children with asthma receiving xolair (omalizumab), a monoclonal anti-
randomised controlled trial. Lancet 2002;360:1715-1721. immunoglobulin e antibody. Pediatrics 2004;113:e308-312.
11. Kikuchi Y, Okabe S, Tamura G, Hida W, Homma M, Shirato K, Takishima T. 20 Recommendations for standardization procedures for the online and offline
Chemosensitivity and perception of dyspnea in patients with a history of near- measurement of exhaled lower respiratory nitric oxide and nasal nitric oxide in
fatal asthma. N Engl J Med. 1994;330(19):1329–1334. adults and in children. Am J Respir Crit Care Med. 2005;171:913-930.
4

5. Separate recommendations have also been developed for children. • Monitoring patient compliance
An elevated eNO level is suggestive of an inadequate anti-
Clinical Utility of eNO inflammatory regimen, which may be due to poor compliance
Exhaled nitric oxide measurement offers new benefits for or under-medication.24 A study by Beck-Ripp and his colleagues
asthma management. showed that there was a strong correlation between reduction
in eNO values and patient compliance (measured as percentage
• Predicting steroid response of prescribed medication taken). In this study, the researchers
An elevated eNO level is highly predictive of a positive response followed 54 patients between the ages of 6 and 16 over 16
to ICS.21 Smith et al showed that eNO levels are very good weeks. The results showed that there was a 50% reduction in
indicators of response to steroid in people with undiagnosed eNO values with higher compliance.
respiratory symptoms. Exhaled nitric oxide was shown to be
• Predicting exacerbations
more accurate than spirometry, peak flow meters, bronchodilator
response and airway hyper-responsiveness (AHR). This study An elevated eNO level at a clinic visit has been shown to be
followed 52 subjects in a single-blind, fixed sequence, placebo- associated with an increased risk for an exacerbation in the
controlled trial of inhaled fluticasone over 4 weeks. Similar results following two weeks.25 In this study, moderate and severe-
were found in another study 22 (Figure 1.1 below) involving 73 persistent asthma patients were evaluated during a routine clinic
steroid-naïve subjects with uncontrolled asthma which showed visit and then noted whether they had an exacerbation within
about 50% reduction in eNO levels following ICS therapy over 2 weeks of the initial appointment. Those with an exacerbation
2 weeks. The study also showed that eNO was a significantly had a higher mean eNO (29.67 ppb ± 14.48) compared to those
better predictor of response to steroid therapy than conventional who did not (12.92 ppb ± 5.17), p = 0.002. A nominal logistic
lung function tests. Additionally, a 35% improvement in asthma regression model to determine those variables that predict
symptom scores were seen following the 2-week therapy. asthma exacerbation found that eNO was the only significant
predictor, p = 0.03.
TAS = Total Asthma In another study26 with 31 subjects (19 adults and 12 children)
Normalized measure of ability to predict steroid use.
eNO is a more reliable Score
predictor of steroid eNO = Exhaled Nitric
using the Insight system, it was shown that by regularly
response than lung Oxide monitoring the diurnal changes in eNO levels, it is possible to
function
FEV1 = Forced predict asthma exacerbations up to 1 week in advance. In this
Expiratory
Volume in
study, spirometry measurements showed no indication of an
1 Second impending exacerbation. During this study, subjects measured
Rev = FEV1 and recorded eNO levels and peak flow values twice daily
Reversibility
(morning and evening). Once a week they also performed a
4-Var = Regression
Model Using spirometry measurement at the study site. The subjects also
All 4 Variables maintained a diary of asthma symptoms. The analysis showed
4-var TAS eNO Rev FEV that a change in the week-to-week pattern of diurnal change in
eNO values predicted an exacerbation. It was also clear that
morning eNO values are better predictors than evening eNO
Figure 1.1 values. See Figure 2.1.
• Improving titration of medication
Study Day Relative
Smith et al showed that using eNO to guide ICS dose in addition 80
eNO (ppb), PEF ( % of Personal Best)
to Exacerbation
to clinical management compared with clinical management alone 70
Evening eNO
significantly reduced the dose of inhaled steroid while showing a 60 Morning eNO
numerical reduction in exacerbations.23 In a single-blind, placebo- 50 Overnight
controlled trial, the researchers randomly assigned 97 patients 40 Change
Evening PEF
with asthma who had been regularly receiving treatment with 30
Morning PEF
inhaled corticosteroids, to have their corticosteroid dose adjusted, 20
No. of subjects
in a stepwise fashion, on the basis of either eNO measurements 10
observed
or an algorithm based on conventional guidelines. After the 0
-14 -7 0 7
optimal dose was determined (phase 1), patients were followed
up for 12 months (phase 2). They found that a 40% reduction in
the dose of ICS can be achieved without loss of asthma control. Figure 2.1
21 Smith AD, Cowan JO, Brassett KP et al. Exhaled nitric oxide: a predictor of steroid
, 24 Beck-Ripp J, Griese M, Arenz S, Koring C, Pasqualoni B, Bufler P Changes of
.
response. Am J Respir Crit Care Med. 2005;172(4):453-459. exhaled nitric oxide during steroid treatment of childhood asthma. Eur Respir J
2002;19(6):1015-1019.
22 Dreon DM, Berger WE, Hutchins EE, and Parikh BR. Exhaled Nitric Oxide Predicts
Use of Controller Medication. J Allergy Clin Immunol 2008;121(2):S157 Scientific 25 Harkins MS, Fiato KL, Iwamoto GK. Exhaled nitric oxide predicts asthma
poster at AAAAI 2008 (NOT PUBLISHED). exacerbation. J Asthma. 2004;41(4):471-476.
23 Smith AD, Cowan JO, Brassett KP Herbison GP Taylor DR. Use of exhaled nitric
, , 26 Wolfe JD, Dreon DM, Hutchins EE, and Parikh BR. Relationship of Exhaled
oxide measurements to guide treatment in chronic asthma. N Engl J Med. Nitric Oxide and Peak Expiratory Flow to Loss of Asthma Control. J Allergy Clin
2005.;352(21):2163-2173. Immunol 2008;121(2):S159 Scientific poster at AAAAI 2008 (NOT PUBLISHED).
5

6. Performing eNO Testing is Simple and steadily through a disposable breath tube, and the results appear
Straightforward on the display within one minute. Patient data can be stored and
maintained in patient cards for trend analysis or downloaded to a
Exhaled nitric oxide testing is an accurate and reliable measure of printer for patients’ files.
airway inflammation that is:
With an accurate measure of their patients’ airway inflammation
• Non-invasive and customized reports for each patient, physicians can
• Patient-friendly significantly improve the precision of prescribed therapy.
• Fast and suitable for routine clinical analysis
The eNO test is simple to administer compared to some of the
conventional lung function testing methods or breath analyses.
The patient has to be seated and is required to exhale steadily for
11 seconds after taking in a deep breath. The device measures the
eNO level and displays a number on the screen. The interpretation
is based on this single numerical value rather than on a complex
tracing or profile. Historical values of eNO can be added to gain
better understanding of the patient’s disease progression.
Important aspects of any system that measures exhaled nitric
oxide include:
Figure 3.1. Insight Monitor
• Detection of trace amounts of the gas in parts per billion (ppb)
• Constant expiratory flow rate due to flow dependence of Insight Sensor Technology
exhaled nitric oxide
Apieron is the first company to successfully implement a
• Exclusion of nasal nitric oxide technique utilizing sol-gel technology to make a commercial
biosensor for the detection of exhaled nitric oxide. The Insight
3. Insight™ eNO System sensor is a disposable, plastic cartridge that contains a path for
exhaled breath to flow through and a sol-gel based biosensor for
Indications for Use detecting nitric oxide. The gas flow path contains desiccant to
The intended use of the Apieron Insight™ eNO System is to control the environment and condition the gas inside the sensor.
quantitatively measure exhaled nitric oxide (eNO) in expired The biosensor consists of a sol-gel matrix (a glass-based three-
human breath as a marker of inflammation in persons with dimensional matrix) with a porous structure that envelopes
asthma. Measurement of eNO in expired human breath by protein molecules which are sensitive to nitric oxide. The
the Apieron Insight eNO System is a non-invasive, simple and biosensor matrix changes its light absorption characteristics when
safe method to measure a decrease in eNO in asthma patients exposed to nitric oxide (NO). This optical change can be measured
that often occurs after treatment with anti-inflammatory and correlated to the concentration of nitric oxide.
pharmacological therapy as an indication of the therapeutic
effects in patients with elevated eNO levels. The Apieron Insight
eNO System is suitable for use in children 8 to 17 years of
age, and in adults 18 years of age and older. As an adjunct to
established clinical assessments, such as spirometry and physical
examination, eNO measurements give the physician an objective
marker to evaluate the patient’s response to anti-inflammatory
therapy. The Apieron Insight eNO System can be used by
trained operators in a physician’s office or laboratory setting. The
Apieron Insight eNO System should not be used in critical care,
emergency care or in anesthesiology.
Prescription device: Federal law restricts this device to sale by or
on the order of a physician.
A Convenient Way to Measure eNO Levels
The Insight eNO System was developed to provide a practical Figure 3.2. Insight Sensor
and accurate means for measuring eNO levels via a simple breath
test. Designed for routine use in physician offices and clinics, the How Is eNO Measured?
Insight system enables physicians to monitor and manage asthma The biosensor encapsulates a heme protein that has a high
on a regular basis. The system includes a small desktop monitor affinity for nitric oxide. The heme protein has a metal active
with a large color display. It employs an eNO sensor to measure site that is specific to nitric oxide (Figure 3.3). As exhaled nitric
nitric oxide from the breath sample. The patient breathes out
6

7. oxide molecules from the breath sample flow into the sensor, • A carbon dioxide filter to remove CO2 from the breath sample.
they diffuse into the porous matrix and react with the protein • A preconditioned desiccant to control the concentration of
molecules. This results in a change in the optical transmission water vapor surrounding the biosensor and to condition the
properties of the matrix in a consistent and measurable way incoming breath sample.
when light of a certain wavelength (412 nm) is passed through
the matrix (see Figure 3.4). • Temperature controllers to control the temperature of the
sensor and gas and to prevent temperature-induced shifts in
The optical signal generated is proportional to the concentration of optical absorbance.
nitric oxide and enables the Insight system to accurately detect trace
amounts of nitric oxide molecules in a single breath sample. Nitric Insight Monitor Technology
oxide measurement results are reported in parts per billion (ppb).
The Insight monitor consists of three subsystems controlled
by a central microprocessor: an eNO measurement system, a
pneumatic system and an user interface.
Optically transparent
porous glass matrix • Measurement system—contains the hardware required to
stabilize the Insight sensor to its operating temperature and
measure the optical absorbance of the biosensor material
when exposed to the breath sample.
• Pneumatic system—controls the exhalation flow rate as outlined
in the American Thoracic Society 2005 recommendations.
• User-friendly interface—guides the operator through the test
sequence and guides the patient through the breath sampling
maneuver.
Embedded heme-protein Accuracy of the System
A study was conducted on 82 non-randomized asthmatic subjects
at a single site comparing eNO measurements taken with both
Figure 3.3. Biosensor the Insight eNO System and the Aerocrine NIOX® System. The
demographic data for this study is presented below. A total of 58
adults (ages ≥18 years) and 20 children (ages <18 years) completed
the study resulting in 78 subjects eligible for analysis. Each subject
2.5 performed two breath maneuvers on each system, and the results
ranged from 10 ppb to 197 ppb on the Insight eNO System. The
testing was performed by three trained technicians. Results were
2
analyzed to evaluate the performance of the Insight eNO System
as it compares to the NIOX System in a clinical setting.
1.5
Optical
Absorbance
measurement
1 band
200
Insight eNO System Result (ppb)
0.5
150
0
395 405 415 425 435 100
Wavelength (nm) NIOX Result ( ppb)
eNO
50 Line of Identity
Figure 3.4. Absorption Spectra (dotted line) Standard
Regression
0
Overcoming Technical Challenges 0 50 100 150 200
NIOX Results (PPB)
Although the heme protein is highly selective for NO, certain
factors will affect the optical absorbance properties of the Figure 4.1. Correlation to reference
biosensor. Detrimental factors include exposure to CO2 from the
breath sample, changes in humidity and changes in temperature.
The Insight system incorporates specific features to counteract
these factors:
7

8. Twenty-four samples containing all of the above potential
Parameter Analysis Results [95% CI] interferents (balance air) and 24 samples containing only air were
Ordinary Least Squares Regression R2 = 0.95 prepared and tested on the Insight eNO System. The mean
Agreement Slope 0.95 [0.90 to 1.00] difference in response was less than 0.05 ppb and was not
Intercept 1.3 ppb [-1.9 to 4.5]
statistically significant between the samples containing potential
interferents and those containing only air.
Bias Mean Difference -1.14 ppb [-3.08 to 0.80]
Precision Mean Absolute Difference 5.86 ppb
In the second set of experiments seven additional compounds
(isoprene, ethanol, acetone, ammonia, acetaldehyde,
Insight
Within-Subject Standard Deviation 3.96 ppb (2.95 to 4.98) methanethiol and methane) were tested at physiologically
Repeatability
relevant concentrations by comparing the response of the Insight
Clinical Agreement Positive Percent Agreement 100% eNO System to a test gas. The test gas contained 0 ppb NO
@ 30 ppb Negative Percent Agreement 93% (nitric oxide). A compound was deemed non-interfering if, at
the tested concentration, the response was within ±5 ppb NO
Table 4.1. Performance of the Insight eNO System equivalent when compared to the nitrogen control.
Agreement: Regression analysis performed on the first None of the tested compounds exhibited interference greater
measurement from each system demonstrated agreement, than ±5 ppb equivalent NO when compared to a nitrogen control.
with an R2 of 0.95, (y=0.95x+1.3 ppb) between the Insight eNO
System and the NIOX System. Clinical interference testing (exogenous compounds):
Bias: Mean difference between the Insight eNO System and The influence of mouthwash containing alcohol, alcohol-
the NIOX System was -1.14 ppb, demonstrating that there is no free mouthwash, toothpaste, breath mints, throat lozenges,
consistent bias between the two systems in clinical use. carbonated beverage with caffeine and caffeine-free carbonated
beverage on eNO was assessed in a clinical study. Twelve
Precision: The mean absolute difference between the Insight healthy adult subjects (9 males and 3 females; mean age 36 ±
eNO System and the NIOX System was 5.86 ppb. 11.8 yrs; range 20-62 yrs) participated in the clinical study. The
Repeatability: The first and second measurements taken on the eNO measurements for adults ranged from 5 ppb to 99 ppb.
Insight eNO System were compared, and the average standard The endpoint was the difference in eNO before as compared to
deviation between measurements was 3.96 ppb for the Insight one hour after exposure to each compound. None of the tested
eNO System. exogenous compounds were found to interfere (at ± 5 ppb) with
the eNO measurement at one hour post-exposure.
Clinical Agreement: Using a clinically relevant decision point
(30 ppb), an analysis was performed that compared the results In pediatric subjects, the influence of alcohol-free mouthwash,
of measurements taken on the Insight eNO System as they toothpaste, breath mints, and caffeine-free carbonated beverage
compared to the NIOX System results from the same subject. on eNO was assessed in a clinical study. Seven healthy children
The 51 subjects identified as elevated by the NIOX System were (6 males and 1 female; ages 5-17 yrs) participated in the clinical
also identified as elevated by the Insight eNO System (100% study. The eNO measurements for children ranged from 3 ppb
positive agreement). Twenty-seven subjects were identified as to 27 ppb. The endpoint was the difference in eNO before as
normal by the NIOX System and 25 of these were identified as compared to one hour after exposure to each compound. None of
normal by the Insight eNO System (93% negative agreement). the exogenous compounds tested were found to interfere (at ± 5
This demonstrates that both the NIOX System and the Insight ppb) with the eNO measurement at one hour post-exposure.
eNO System are highly consistent in detecting subjects with both These studies show that the Insight eNO System can
normal and elevated eNO measurements. accurately and reliably measure exhaled nitric oxide
Interference
Two sets of endogenous interference experiments were conducted.
In the first set of experiments, interference testing was
performed on the Insight eNO System for the following common
constituents of exhaled breath:
• 200 ppm H2 (hydrogen)
• 3 ppm CO (carbon monoxide)
• 100% Relative Humidity (water vapor)
• 0.5% CO2 (carbon dioxide)
• 0 ppb NO (nitric oxide)
8

9. Case Study 1
4. Case Studies
“Let’s go fishing dad!” – Maya, 10, Pensacola FL
Maya is 10 years old and loves the Insight system, he incorporated exhaled nitric oxide (eNO)
to go fishing with her dad on testing into her treatment plan. When he first measured Maya’s
the weekends. She has eNO, it was 44 ppb. He felt it was a little high for her age, but
moderate persistent asthma. he wanted to establish her usual eNO levels over time before
She is very compliant and changing her medication. Over the next 8 weeks, he found that
often corrects her dad when it her eNO values settled at around 30 ppb after initially fluctuating.
comes to managing her He increased her Pulmicort dosage to 200 BID. Over the next 8
asthma. She gets on very well weeks, Maya’s eNO values decreased to the low 20’s. Her doctor
with her doctor, who has been was very pleased with the results but the next time he measured
seeing her for 3 years now. her, she was at 40 ppb. An almost two-fold increase in her eNO
bothered him but further investigation with Maya and her father
Maya has been on Pulmicort®
revealed that she had missed taking her medication recently.
DPI 200 mcg QD. Based
Her eNO values dropped back down to around 20 ppb once she
on her record of asthma
resumed her treatment. By continuing to monitor Maya’s eNO
control, her doctor wanted
levels regularly, her doctor was confident that he could fine-tune
to optimize Maya’s therapy. But he had no objective measure
her medication.
of her airway inflammation to monitor her response. Once he
had access to exhaled nitric oxide (eNO) measurement with
Maya’s history and medical information Titrate medication and monitor compliance with precise information
• Age:10-year-old female
• Classification:Moderate persistent 70 6 weeks
4 months
• Medication:Pulmicort 60
• Dosage:200 mcg QD 50
Missed medication
eNO in ppb
shows up as abnormally
• FEV1:80% high eNO values
40
• eNO:44 ppb
• Other information: 30
- Non-allergic rhinitis 20
200 QD
- Non-allergic conjunctivitis Pulmicort 200 BID Pulmicort
10
- Cold sores
- Occasional headaches Time
Benefits of eNO:
Treatment gap revealed by eNO measurement with the Insight™ eNO System
• Objective validation for a sound clinical decision
• Insight into airway inflammation not manifesting as symptoms
• Timely identification of suboptimal compliance to medication and therapy
Patient benefits from the new treatment paradigm
• Better titrated dosage enables patient to maintain control
9

10. Case Study 2
“I like to win.” – Scott, 23, Fresno CA
Scott is a talented young racer Scott’s eNO was 32 ppb at his first visit, but Dr. Brewster
who loves to drive his all-wheel planned to measure his eNO values over several visits and look
drive car on wet and slippery for patterns before making any treatment changes. Consistent
dirt roads. He competes in with Scott’s irregular compliance, his eNO values varied
many local and regional events. widely. However, these variations did not coincide with Scott’s
He has a keen eye for those symptoms. Most of the time, Scott’s symptoms were normal
fast corners and usually leaves and he felt fine, but his eNO levels were high. Dr. Brewster then
the rest of the racers in the shared the eNO values with Scott and explained the significance,
dust. hoping to convince Scott to take his medications seriously and
regularly. Scott liked having a number that showed him the status
Scott spends a lot of time
of the inflammation of his airways, and started to improve his
outdoors and has complained
compliance which resulted in a reduction and stability of his eNO
about worsening asthma
levels. Subsequently Dr. Brewster changed Scott’s medication
symptoms with increased
from Advair 500 BID (a combination of the 500 mcg of the inhaled
activities. His doctor, Jim
steroid fluticasone and salmeterol, a long acting bronchodilator)
Brewster, knows him too well to ask him to reduce his need
to fluticasone 220 BID alone. Scott’s eNO values are now in the
for speed. Dr. Brewster decided to assess Scott’s airway
low 20’s and do not fluctuate like before. Scott has not had any
inflammation via exhaled nitric oxide (eNO) values as an aid to
exacerbations since he started monitoring his eNO values, and
titrating his controller medications. Scott was on Advair® 500 BID.
Dr. Brewster has been able to reduce the daily dose of inhaled
He suspected that Scott was not compliant and Dr. Brewster
steroids by 50% and stop salmeterol.
knew that Scott had some asthma attacks in the past that landed
him in emergency care.
Improve patient compliance and confidence
Scott’s history and medical information
Prednisone Prednisone & Augmentin
• Age:23-year-old male 80
• Classification:Severe persistent Improved compliance
70
• Medication:Advair
60
• Dosage:500 BID Advair 500 BID to
eNO in ppb
• FEV1:117% 50
Flovent 220/2inh BID
• eNO:32 ppb 40
• Other information 30
- Allergic rhinitis
20
- Severe asthma attacks Advair 500 BID
10
- Hospitalized /intubated in last 18 months
- Occasional headaches 0
1 2 3 4 5 6 7
Time (months)
Benefits of eNO testing
Treatment gap revealed by eNO testing
• Simple and compelling evidence to highlight to the patient the need to follow treatment plan and medication
• Confirm suboptimal compliance with medication and treatment plan
• Provide objective validation for clinical treatment decisions
Patient benefits from the new treatment paradigm
• More confidence from a precisely tailored therapy that fits lifestyle requirements
• Greater awareness and motivation to improve compliance
10

11. Case Study 3
“It feels good to be in control.” - Lynn, 36, Long Island NY
Lynn works in While on Advair® 250/50 BID and QVAR® 80mcg BID (i.e.
emergency care at the 2 inhaled steroids), her doctor decided to monitor Lynn’s
city hospital as a nurse inflammation using eNO testing. Her eNO levels were very high
and loves her job. She (80-128 ppb where normal is about 20 ppb) and Lynn continued
lives with her husband to have almost daily symptoms. Her doctor doubled her QVAR
and two children. Her dosage to 160 BID. Over time, this brought her eNO down to the
life is demanding to 45-50 ppb range but these levels were still elevated. Around that
say the least. She has time, Lynn moved to a new house in Long Island (a surprise family
been living with asthma inheritance) and after the move, there was a further drop in eNO
for almost 14 years to around 20 ppb. Lynn also reported that her symptoms were
now and feels that she getting much better. Lynn and her doctor figured that her older
can’t quite get it under house, which had a moldy basement, might have triggered her
control. Her health has symptoms. Her doctor then reduced her dosage of QVAR back
been a big concern for to just 1 inhalation. He felt confident that he could further drop or
her whole family. She even eliminate her dosage of QVAR and significantly reduce her
has persistent asthma with symptoms most of the time. She has medication by following her eNO levels regularly. Lynn continues
missed many days at work due to her asthma. to work in ER and is happy to be able to focus more on her work
and family.
Track disease progression and see impact of environment
Lynn’s history and medical information
• Age: 36-year-old female 140
• Classification:Severe persistent 120
• Medication: Advair, QVAR
100
• Dosage:Advair 250/50 BID and QVAR 80 BID QVAR 80 2inh BID
eNO in ppb
• FEV1:51% 80
• eNO: 85 ppb Moved to a
60
• Other information: new house
40 Decreased to
- Asthma x 14 years QVAR 80
- Regularly symptomatic 1 inh BID
20
- Allergic Rhinitis
0
- Ragweed, mold, dander 1 2 3 4 5 6 7 8
- Intermittent psoriasis Time (months)
Benefits of eNO testing
Treatment gap revealed by eNO testing
• Despite 2 controller medications, eNO indicated that airway inflammation was uncontrolled
• Exhaled nitric oxide (eNO) showed that airway inflammation was decreasing after a change in environment.
• Exhaled nitric oxide (eNO) allowed the tapering of medication in the better environment.
Patient benefits from the new treatment paradigm
• Titration of therapy to optimize asthma control
• Improved quality of life
11

12. 5. Exhaled Nitric Oxide Cost Model 6. Coding Information for Exhaled Nitric
This cost model provides an insurance payer with the Oxide (eNO)-CPT 95012
reimbursement costs of eNO patient testing with the Insight In 2007 the CPT editorial committee added a specific code to the
,
system and the expected savings in medical resources resulting CPT Coding Book for Nitric Oxide Expired Gas Determination.
from improved asthma control.The cost model: With this action, the procedure should be recognized as a
• Estimates the number of patients that are likely to undergo standard service provided to patients. The committee felt it
eNO testing over a three year period. appropriate to add this code to the Category I codes instead
of placing it in the Category III codes as a temporary or new
• Estimates total eNO testing reimbursement costs to the services code. The Category I codes are considered consistent
insurance payer. with contemporary medical practice and are performed by
• Estimates the number of asthma exacerbation events likely to providers across the country. Determination of exhaled nitric
be avoided by patients monitored with eNO. oxide (eNO) is considered a service which is consistent with
• Estimates cost savings in medical resources (hospitalization, contemporary medical practice for the evaluation of patients with
respiratory complaints.
ER visits, office visits, drug use) due to avoidance of asthma
exacerbation events. Centers for Medical Services (Medicare) also determined that
• Estimates the net cost to the insurance payer of eNO testing the service should be recognized as a payable service for all
reimbursement minus medical resource savings. Medicare beneficiaries. In doing this, the RUC committee
(Relative Value Update Committee) assigned an RVU value of
Please contact us at care@apieron.com if you would like to see
0.50. This value does not have a physician work component RVU,
how the model can be applied to your plan.
only an overhead and malpractice RVU. RVU or relative value unit
determines what the reimbursement will be for Medicare as well
as many other carriers. Medicare has a conversion factor which
may be higher or lower than the third party payers to determine
the final reimbursement for the code.
The code assigned for the Nitric Oxide Expired Gas Determination
is 95012©. According to the CPT subsection heading for 2008,
the interpretation and report for the test is included in the testing
code. If a “significant and separately identifiable” evaluation
and management service is provided in addition to the testing,
then an evaluation and management code may be coded in
addition to the testing code. The ‘25 modifier’ would need to be
added to the evaluation and management code (E/M) in order for
both the test, and the evaluation and management code to be
appropriately reimbursed.
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Managing asthma is a breath away™ Insight™ is a trademark of Apieron, Inc.
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