Nebulizer
Nebulizer | ||
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Specialty pulmonology | | |
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In
Medical uses
Guidelines
Various asthma guidelines, such as the Global Initiative for Asthma Guidelines [GINA], the British Guidelines on the management of Asthma, The Canadian Pediatric Asthma Consensus Guidelines, and United States Guidelines for Diagnosis and Treatment of Asthma each recommend
Effectiveness
Recent evidence shows that nebulizers are no more effective than metered-dose inhalers (MDIs) with spacers.[5] An MDI with a spacer may offer advantages to children who have acute asthma.[3][6][5] Those findings refer specifically to the treatment of asthma and not to the efficacy of nebulisers generally, as for COPD for example.[5] For COPD, especially when assessing exacerbations or lung attacks, there is no evidence to indicate that MDI (with a spacer) delivered medicine is more effective than administration of the same medicine with a nebulizer.[7]
The European Respiratory Society highlighted a risk relating to droplet size reproducibility caused by selling nebulizer devices separately from nebulized solution. They found this practice could vary droplet size 10-fold or more by changing from an inefficient nebulizer system to a highly efficient one.[4][5] Two advantages attributed to nebulizers, compared to MDIs with spacers (inhalers), are their ability to deliver larger dosages at a faster rate, especially in acute asthma; however, recent data suggests actual lung deposition rates are the same. In addition, another trial found that a MDI (with spacer) had a lower required dose for clinical result compared to a nebulizer.[3]
Beyond use in chronic lung disease, nebulizers may also be used to treat acute issues like the inhalation of toxic substances. One such example is the treatment of inhalation of toxic hydrofluoric acid (HF) vapors.[8] Calcium gluconate is a first-line treatment for HF exposure to the skin. By using a nebulizer, calcium gluconate is delivered to the lungs as an aerosol to counteract the toxicity of inhaled HF vapors.
Aerosol deposition
The lung deposition characteristics and efficacy of an aerosol depend largely on the particle or droplet size. Generally, the smaller the particle the greater its chance of peripheral penetration and retention. However, for very fine particles below 0.5 μm in diameter there is a chance of avoiding deposition altogether and being exhaled. In 1966 the Task Group on Lung Dynamics, concerned mainly with the hazards of inhalation of environmental toxins, proposed a model for deposition of particles in the lung. This suggested that particles of more than 10 μm in diameter are most likely to deposit in the mouth and throat, for those of 5–10 μm diameter a transition from mouth to airway deposition occurs, and particles smaller than 5 μm in diameter deposit more frequently in the lower airways and are appropriate for pharmaceutical aerosols.[9] Nebulizing processes have been modeled using computational fluid dynamics.[10]
Types
Pneumatic
Jet nebulizer
The most commonly used nebulizers are jet nebulizers, which are also called "atomizers".
Mechanical
Soft mist inhaler
The medical company Boehringer Ingelheim also invented a device named Respimat Soft Mist Inhaler in 1997. This new technology provides a metered dose to the user, as the liquid bottom of the inhaler is rotated clockwise 180 degrees by hand, adding a build up tension into a spring around the flexible liquid container. When the user activates the bottom of the inhaler, the energy from the spring is released and imposes pressure on the flexible liquid container, causing liquid to spray out of 2 nozzles, thus forming a soft mist to be inhaled. The device features no gas propellant and no need for battery/power to operate. The average droplet size in the mist was measured to 5.8 micrometers, which could indicate some potential efficiency problems for the inhaled medicine to reach the lungs. Subsequent trials have proven this was not the case. Due to the very low velocity of the mist, the Soft Mist Inhaler in fact has a higher efficiency compared to a conventional pMDI.[14] In 2000, arguments were launched towards the European Respiratory Society (ERS) to clarify/expand their definition of a nebulizer, as the new Soft Mist Inhaler in technical terms both could be classified as a "hand driven nebulizer" and a "hand driven pMDI".[15]
Electrical
Ultrasonic wave nebulizer
Ultrasonic wave nebulizers were invented in 1965
Vibrating mesh technology
A new significant innovation was made in the nebulizer market around 2005, with creation of the ultrasonic Vibrating Mesh Technology (VMT). With this technology a mesh/membrane with 1000–7000 laser drilled holes vibrates at the top of the liquid reservoir, and thereby pressures out a mist of very fine droplets through the holes. This technology is more efficient than having a vibrating piezoelectric element at the bottom of the liquid reservoir, and thereby shorter treatment times are also achieved. The old problems found with the ultrasonic wave nebulizer, having too much liquid waste and undesired heating of the medical liquid, have also been solved by the new vibrating mesh nebulizers. Available VMT nebulizers include: Pari eFlow,[19] Respironics i-Neb,[20] Beurer Nebulizer IH50,[21] and Aerogen Aeroneb.[22] As the price of the ultrasonic VMT nebulizers is higher than models using previous technologies, most manufacturers continue to also sell the classic jet nebulizers.[23]
Use and attachments
Nebulizers accept their medicine in the form of a liquid solution, which is often loaded into the device upon use.
Usually, the aerosolized medicine is inhaled through a tube-like mouthpiece, similar to that of an inhaler. The mouthpiece, however, is sometimes replaced with a face mask, similar to that used for inhaled anesthesia, for ease of use with young children or the elderly. Pediatric masks are often shaped like animals such as fish, dogs or dragons to make children less resistant to nebulizer treatments. Many nebulizer manufacturers also offer pacifier attachments for infants and toddlers. But mouthpieces are preferable if patients are able to use them since face-masks result in reduced lung delivery because of aerosol losses in the nose.[11]
After use with corticosteroid, it is theoretically possible for patients to develop a
History
The first "powered" or pressurized inhaler was invented in France by Sales-Girons in 1858.[24] This device used pressure to atomize the liquid medication. The pump handle is operated like a bicycle pump. When the pump is pulled up, it draws liquid from the reservoir, and upon the force of the user's hand, the liquid is pressurized through an atomizer, to be sprayed out for inhalation near the user's mouth.[25]
In 1864, the first steam-driven nebulizer was invented in Germany. This inhaler, known as "Siegle's steam spray inhaler", used the
The first pneumatic nebulizer fed from an electrically driven gas (air) compressor was invented in the 1930s and called a Pneumostat. With this device, a medical liquid (typically epinephrine chloride, used as a bronchial muscle relaxant to reverse constriction).[27] As an alternative to the expensive electrical nebulizer, many people in the 1930s continued to use the much more simple and cheap hand-driven nebulizer, known as the Parke-Davis Glaseptic.[28]
In 1956, a technology competing against the nebulizer was launched by Riker Laboratories (3M), in the form of pressurized metered-dose inhalers, with Medihaler-iso (isoprenaline) and Medihaler-epi (epinephrine) as the two first products.[29] In these devices, the drug is cold-fill and delivered in exact doses through some special metering valves, driven by a gas propellant technology (i.e. Freon or a less environmentally damaging HFA).[24]
In 1964, a new type of electronic nebulizer was introduced: the "ultrasonic wave nebulizer".[30] Today the nebulizing technology is not only used for medical purposes. Ultrasonic wave nebulizers are also used in humidifiers, to spray out water aerosols to moisten dry air in buildings.[17]
Some of the first models of
See also
- Heated humidified high-flow therapy
- Inhaler
- Humidifier
- Vaporizer
- List of medical inhalants
- Spray bottle
References
- ^ Medical Dictionary. "Nebulizer". Retrieved 2010-11-01.
- ^ British Spelling of Nebulizer Medical Dictionary. "Definition". Archived from the original on 2010-07-01. Retrieved 2010-11-01.
- ^ PMID 20103617.
- ^ PMID 11510796.
- ^ PMID 24037768.
- PMID 12537167.
- PMID 27569680.
- S2CID 37322396.
- ^ The science of nebulised drug delivery, p6
- .
- ^ a b Finlay, W.H. (2001). The Mechanics of Inhaled Pharmaceutical Aerosols: An Introduction. Academic Press.
- ^ ISBN 978-0-8247-4253-9.
- PMID 10155650.
- ^ Boehringer Ingelheim (2003). "How it works: Respimat Soft Mist Inhaler". Archived from the original on 2007-05-27. Retrieved 2005-08-16.
- ^ Denyer J, et al. (2000). "New liquid drug aerosol devices for inhalation therapy". Eur Respir Rev. 10: 187–191.
- ^ US patent 3243122, Snaper, Alvin A., "Ultrasonic Spray Apparatus", published 29 March 1966 Archived 29 October 2018 at the Wayback Machine
- ^ a b BOGA Gmbh. "Operating principle of ultrasonic humidifier". Archived from the original on 2010-11-14. Retrieved 2010-04-05.
- ^ Knoch, M., Finlay, W.H. (2002). "Ch. 71 Nebuliser Technologies". In Rathbone, Hadgraft, Roberts (eds.). Modified-Release Drug Delivery Technology. Marcel Dekker. pp. 849–856.
- ^ PARI Pharma (2008). "Leading aerosol therapies worldwide, delivery with eFlow". Archived from the original on 2010-03-28. Retrieved 2010-04-09.
- ^ Philips Respironics (2010). "Active Aerosol Delivery, The I-neb and Vibrating Mesh Technology". Archived from the original on 2010-08-04. Retrieved 2010-04-09.
- ^ Beurer (2015). "Product details of IH50 nebulizer, with a vibrating membrane". Archived from the original on 2015-05-13. Retrieved 2015-04-21.
- ^ Aerogen (2009). "Micropump nebulizers, Aeroneb, Vibrating Mesh Technology". Archived from the original on 2010-02-03. Retrieved 2010-04-09.
- ^ Team E (2019-12-09). "Nebulizer Machine and Its Overview". Index of Sciences. Retrieved 2020-05-25.
- ^ PMID 17356785.
- ^ Inhalatorium. "Pressurized inhaler invented by Sales-Girons". Archived from the original on 2013-01-03. Retrieved 2010-04-05.
- ^ Inhalatorium. "Siegle's steam spray inhaler". Archived from the original on 2004-08-26. Retrieved 2010-04-05.
- ^ Inhalatorium. "First electrical nebulizer (Pneumostat)". Archived from the original on 2005-02-17. Retrieved 2010-04-05.
- ^ Inhalatorium. "The hand driven nebulizer "Parke-Davis Glaseptic". Archived from the original on 2004-09-06. Retrieved 2010-04-05.
- ^ Riker Laboratories (1960-03-16) [1956-03-21]. "Self-propelling pharmaceutical compositions (for a pMDI)". GB patent. Retrieved 24 Jan 2016.
- ^ Devilbiss Co. (1967-05-17) [1964-02-10]. "Method and apparatus for producing aerosols (ultrasonic nebulizer)". GB patent. Retrieved 24 Jan 2016.
- ^ Hon Lik (2004-04-14). "An aerosol electronic cigarette". CN patent. Retrieved 2006-12-27.
- ^ Hon Lik (2006-05-16). "Emulation aerosol sucker". CN patent. Retrieved 2009-02-11.