Biomaterial Database

Variation in nebulizer aerosol output and weight output from the Mefar dosimeter: implications for multicentre studies. 1997

S Chinn, and W A Arossa, and D L Jarvis, and C M Luczynska, and P G Burney

Dept of Public Health Medicine, United Medical School, London, UK.

The active aerosol component of nebulizers is less than 100% of output by weight, and may vary between nebulizers in different batches from the same manufacturer. A measure of bronchial responsiveness to methacholine, which can overcome this problem, is required. One hundred and sixty nebulizers from 21 centres in the European Community Respiratory Health Survey (ECRHS) were calibrated for aerosol and weight output. Methacholine challenge data were obtained for 1,021 subjects in three English centres of the ECRHS. The dose producing a 20% fall in forced expiratory volume in one second (PD20), and log-slope, the regression slope of percentage decline in FEV1 with log (dose), were calculated, with and without calibration of nebulizers by weight. Within-centre variation in nebulizer percentage aerosol output had a coefficient of variation of less than 10%. Unlike PD20, log-slope is unaffected by constant percentage overestimation of nebulizer output. Variation in output by weight of nebulizers of 10% had little affect on log-slope. It is, however, affected by the scheduled range of doses. Log-slope shows advantages in analysis, and is less affected by variation in nebulizer output. It can be used for multicentre comparisons, with restriction to a common dose protocol.

UI	MeSH Term	Description	Entries
D009330	Nebulizers and Vaporizers	Devices that cause a liquid or solid to be converted into an aerosol (spray) or a vapor. It is used in drug administration by inhalation, humidification of ambient air, and in certain analytical instruments.	Atomizers,Inhalation Devices,Inhalators,Inhalers,Vaporizers,Nebulizers,Vaporizers and Nebulizers,Atomizer,Device, Inhalation,Devices, Inhalation,Inhalation Device,Inhalator,Inhaler,Nebulizer,Vaporizer
D001985	Bronchial Provocation Tests	Tests involving inhalation of allergens (nebulized or in dust form), nebulized pharmacologically active solutions (e.g., histamine, methacholine), or control solutions, followed by assessment of respiratory function. These tests are used in the diagnosis of asthma.	Allergen Bronchial Provocation Tests,Allergen Challenge, Endobronchial,Antigen Bronchial Provocation Tests,Bronchial Allergen Challenge,Bronchial Challenge Tests,Inhalation Provocation Tests,Provocation Tests, Bronchial,Endobronchial Challenge Tests,Allergen Challenge, Bronchial,Allergen Challenges, Bronchial,Allergen Challenges, Endobronchial,Bronchial Allergen Challenges,Bronchial Challenge Test,Bronchial Provocation Test,Challenge Test, Bronchial,Challenge Test, Endobronchial,Challenge Tests, Bronchial,Challenge Tests, Endobronchial,Challenge, Bronchial Allergen,Challenge, Endobronchial Allergen,Challenges, Bronchial Allergen,Challenges, Endobronchial Allergen,Endobronchial Allergen Challenge,Endobronchial Allergen Challenges,Endobronchial Challenge Test,Inhalation Provocation Test,Provocation Test, Bronchial,Provocation Test, Inhalation,Provocation Tests, Inhalation,Test, Bronchial Challenge,Test, Bronchial Provocation,Test, Endobronchial Challenge,Test, Inhalation Provocation,Tests, Bronchial Challenge,Tests, Bronchial Provocation,Tests, Endobronchial Challenge,Tests, Inhalation Provocation
D002138	Calibration	Determination, by measurement or comparison with a standard, of the correct value of each scale reading on a meter or other measuring instrument; or determination of the settings of a control device that correspond to particular values of voltage, current, frequency or other output.	Calibrations
D005541	Forced Expiratory Volume	Measure of the maximum amount of air that can be expelled in a given number of seconds during a FORCED VITAL CAPACITY determination . It is usually given as FEV followed by a subscript indicating the number of seconds over which the measurement is made, although it is sometimes given as a percentage of forced vital capacity.	Forced Vital Capacity, Timed,Timed Vital Capacity,Vital Capacity, Timed,FEVt,Capacities, Timed Vital,Capacity, Timed Vital,Expiratory Volume, Forced,Expiratory Volumes, Forced,Forced Expiratory Volumes,Timed Vital Capacities,Vital Capacities, Timed,Volume, Forced Expiratory,Volumes, Forced Expiratory
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000336	Aerosols	Colloids with a gaseous dispersing phase and either liquid (fog) or solid (smoke) dispersed phase; used in fumigation or in inhalation therapy; may contain propellant agents.	Aerosol
D001249	Asthma	A form of bronchial disorder with three distinct components: airway hyper-responsiveness (RESPIRATORY HYPERSENSITIVITY), airway INFLAMMATION, and intermittent AIRWAY OBSTRUCTION. It is characterized by spasmodic contraction of airway smooth muscle, WHEEZING, and dyspnea (DYSPNEA, PAROXYSMAL).	Asthma, Bronchial,Bronchial Asthma,Asthmas
D015337	Multicenter Studies as Topic	Works about controlled studies which are planned and carried out by several cooperating institutions to assess certain variables and outcomes in specific patient populations, for example, a multicenter study of congenital anomalies in children.	Multicenter Trials,Multicentre Studies as Topic,Multicentre Trials,Multicenter Trial,Multicentre Trial,Trial, Multicenter,Trial, Multicentre,Trials, Multicenter,Trials, Multicentre