Exhaled nitric oxide (eNO) is produced by airway cells, and its concentration is highly correlated with the number of inflammatory cells, serving as a biomarker of airway inflammation. [1] There are currently two tests available to determine exhaled nitric oxide concentration: the oral exhaled nitric oxide test and the nasal exhaled nitric oxide test. The measurement of exhaled nitric oxide is widely used in the diagnosis and monitoring of respiratory diseases.
Chinese name
Exhaled nitric oxide
Foreign name
exhaled nitric oxide, eNO
produced
Airway Cells
Object
Nitric Oxide
Contents
1 Source
< p>2 Clinical significance3 Determination method
4 Influencing factors
1 Source editor
Nitric oxide (NO) is the A kind of biological regulatory factor produced, which plays an important role in various physiological and pathological links. It synthesizes nitric oxide from arginine under the action of nitric oxide synthase (NOS), and at the same time produces citrulline. NOS in the human body is roughly divided into three categories. Endothelial type (eNOS) and neuronal type (nNOS) are calcium-dependent structural expressions and exist under normal physiological conditions; inducible nitric oxide synthase (iNOS) is non-calcium-dependent. Dependent inducible expression is induced under special conditions.
The composition of nitric oxide in exhaled breath is as follows:
Exhaled NO = NO decomposed by diet + NO inhaled from the environment + NO produced by the airway + NO produced by cardiovascular and gastroesophageal organs and transferred to the airway
Airway NO=upper respiratory tract NO+lower respiratory tract NO
The nitric oxide produced by the airway is what we usually call exhaled nitric oxide, which can be used as a biological agent of airway inflammation. Marker, iNOS is the isoform that plays a dominant role in the production of nitric oxide in the airways. Exhaled nitric oxide can be measured when meeting the "International Standards" jointly developed by the American Thoracic Society (ATS) and the European Respiratory Society (ERS) in 2005.
2 Clinical Significance Editor
Inflammatory factors and drugs affect the concentration of eNO by acting on iNOS. The concentration increases during inflammation and decreases during anti-inflammation, so eNO is used as a biomarker of airway inflammation. things. eNO measurement is widely used in the diagnosis and monitoring of various respiratory diseases, such as bronchial asthma, chronic cough, COPD, etc.
3 Measurement Method Editor
Technology
Electrochemical Current Sensor
Nanocoulomb Electricity Sensor
Chemiluminescence Analyzer
Brand
MINO / (Medisoft)
Sunvou
NIOX / EcoMedics
Performance
p>
Range: 0-300ppb
Accuracy: <5ppb or 10%
0-3000ppb
<5ppb or 10%
0-3000 ppb
1 ppb
Function
Online mouth breathing (50mL/s)
(Nasal breathing usually >300ppb)
Online oral breathing (flow rate can be adjusted)
Offline, tidal
Nasal breathing (optional)
Bronchi/ Alveolar NO (optional)
Exhaled carbon monoxide CO (optional)
Exhaled hydrogen sulfide H2S (under development)
Online oral exhalation (flow can be adjusted)
Offline, tidal
Nasal NO (optional)
Bronchial/alveolar NO (optional)
Method
Online
Online, offline, moisture,
Electronic automatic control of flow
Online, offline, moisture,
Flow Mechanical manual control
Quality control
FDA requires daily calibration
Yes, standard gas calibration
Self-calibration patented technology assistance
Yes, standard gas calibration