Metered dose inhalers
Metered dose inhalers are sprays in which the active ingredient is in a pressurized container together with the propellant.[2] Pressing down on the pressurized container during inhalation triggers the spray. Here, the timing of the release of the spray during inhalation is crucial, as this must necessarily occur at the beginning of the inhalation. Patients may find it difficult to coordinate inhalation and simultaneous downward pressure.

It may be beneficial to use inhalation aids (spacers). This leads to easier coordination of triggering the spray burst and inhalation.[2] Since inhalation of the different models is similar, Kata®, supported by AI, provides guidance on breathing maneuvers and handling of the most common metered dose inhalers.

Standard metered dose inhaler
If the metered dose inhaler is being used for the first time, it should be shaken well beforehand and up to four sprays should be released into the air.[3] A similar procedure should be followed if it has not been used for more than five days. In addition, the mouthpiece should be cleaned once a day with warm water and then dried.[4] Common mistakes with metered dose inhalers include improper coordination, inhaling or exhaling too shallowly, improper storage, lack of shaking, and improper body posture.[5] The following are other common mistakes.

Other metered dose inhalers include:

• Aerosphere-Dosieraerosol
• Dosieraerosol mit Zählwerk
• Autohaler (breath-controlled)
• Easi Beathe (breath-controlled)

Dry powder inhalers (DPI)
Powder inhalers have the advantage over metered dose inhalers in that they make it easier for the patient to coordinate inhalation and release the medication.[6] Here, the dose of medication is released in one breath with inhalation. There are many different dry powder inhaler models on the market, but the principle of inhalation is similar. The active ingredient is present as a powder and is inhaled with a strong breath.[6] The particle size of the medication here depends on the strength of the inhalation. The faster the inhalation speed, the smaller the particles. If the inhalation speed is too slow, the large particles with the active ingredient may remain on the tongue and not reach the lungs. However, most inhalers do not provide feedback on whether the inhalation was sufficient. In addition, patients are not always able to produce sufficient inhalation strength to achieve optimal clinical benefit.[7],[8]

If the powder becomes moist, effective inhalation is also no longer possible, as this can cause the powder to clump. For this reason, special care should be taken to avoid breathing into the inhaler prior to inhalation. In addition, the inhaler should not be stored in the bathroom, so that it is exposed to as little humidity as possible.

Dry powder inhalers also differ in shape and appearance. Some even resemble metered dose inhalers. However, using a powder inhaler like a metered dose inhaler can lead to loss of medication. This is because if the DPI is shaken after activation, the dose may fall out.

Some examples of dry powder inhalers are:

NEXThaler®
The active ingredient in the NEXThaler® is in a protected chamber. The cover of this chamber is removed by an inhalation when it is forceful enough (at least 40L/min) and the dose is provided once the cover of the device is fully open.[9] The forceful breath then delivers this dose to the lungs. The Nexthaler provides feedback on whether the inhalation was successful: a click during the inhalation indicates the cover is open and the number of available inhalations decreases by one.

The NEXThaler® is supported by Kata®.

Ellipta®
In the Ellipta®, the dose of active ingredient is individually packaged for each stroke.[10] It is breath-controlled, as are all dry powder devices, but the dose is provided as soon as the flap is opened. This leaves the powder unprotected and exhalation into the inhaler should be avoided at all costs, otherwise the powder may become moist or blown away. The patient receives no feedback from the Ellipta® as to whether the breath was forceful enough. In addition, the orientation of the device during inhalation is important.

The Ellipta® is supported by Kata®.

Turbohaler®
The powder of the Turbohaler® gets onto a sieve by turning a mechanism and is then ready to be inhaled.[11] This powder is mostly a pure substance of the drug, which is not enriched with lactose. After activating the dose, make sure the inhaler is in an upright position (mouthpiece facing up). In this case, the dose of the inhaler lies open and unprotected, so that the orientation of the inhaler and moisture through exhalation is also critical here.

The Turbohaler® is supported by Kata®.

Breezhaler®
The Breezhaler® is a capsule inhaler. The medication is safely stored in a capsule that is pierced in the inhaler before inhalation.[12] A major advantage is that patients can see after inhalation whether and how much of the medication is still in the capsule. Thus, they have visual feedback and can inhale the rest of the capsule if necessary. Especially for elderly patients with osteoarthritis, the capsule may sometimes not be easy to handle. In order to pierce the capsule, the two buttons on the side must be pressed and completely released again before inhalation, as the capsule must be able to rotate.

The Breezhaler® is supported by Kata®.

Easyhaler®
When inhaling with the Easyhaler®, the active ingredient is in a container and a dose is released during the inhalation process.[13] Care should be taken as this inhaler looks like a metered dose inhaler but must be operated differently. The Easyhaler® should only be shaken before, but not after activation, otherwise the dose could be shaken out. The Easyhaler® is also very sensitive to moisture, so it should not be stored in the bathroom. For this reason, the device must be stored in a plastic container provided.

The Easyhaler® is supported by Kata®.

Other powder inhalers are:

• Aerolizer
• Cyclohaler
• Diskus
• Elpenhaler
• Forspiro
• Genuair
• HandiHaler
• Neumohaler
• Novolizer
• Salflutin Inhalationsgerät
• Spiromax
• Tiotropium Glenmark Inhaler
• Twisthaler
• Zonda

Softmist inhalers
The Respimat® belongs to the category of softmist inhalers and produces a fine, long-lasting and slowly spreading spray cloud. This is triggered without propellant or electrical energy. The active ingredient of the Respimat is contained in a cartridge.[14]

Before using the Respimat for the first time, it must be made ready for use and the cartridge inserted.[14] Then the inhaler can be made ready for inhalation by cocking the spring, with the protective cap closed. The inhaler is triggered by hand during inhalation.

The Respimat® is supported by Kata®.

Moist inhalation
In moist inhalation, an inhalable aerosol is prepared from a liquid active ingredient formulation, usually provided in an extra ampoule.[15] This is done using a jet, ultrasound or membrane nebulizer. Here, expectorant, respiratory tract dilating, anti-inflammatory or antibiotic drugs are nebulized. Either a ready-to-use solution or a carrier solution with the drug as a suspension is used here.[15].

Important note: Corticosteroids are suspensions and therefore cannot be inhaled with an ultrasonic nebulizer. The particles of the suspension are not nebulized by the ultrasound and cannot be inhaled.

Possible wet inhalers are:

• OMRON MicroAIR U100
• PARI BOY SX
• PARI COMPACT2
• PARI BOY free
• PARI VELOX
• PARI PEP S
• PARI SINUS2
• PARI SINUS
• MicroDrop Calimero2
• Aeroneb GO
• AKITA JET
• eFlow rapid
• I-neb
• Lamira-Inhalationssystem

The health app Kata® offers support for respiratory patients to cope with the inhaler jungle. The digital technologies help sufferers improve the handling of all common inhaler devices as part of their inhalation therapy.

To achieve efficient inhalation, Kata® shows step-by-step instructions on how to optimally prepare and perform inhalation. Kata® does this by using the signal from the camera and microphone of the patient’s own smartphone and shows in real time where improvements are desirable and how the dose to the lungs can be maximized. At the end of the inhalation, an individual result and tips are displayed on what can perhaps be done better during the next inhalation. This makes respiratory therapies much easier and more effective for patients, as drug delivery can be significantly optimized.

We have aroused your interest and you would like to test Kata®? Then register via our contact form and request a free app test access.

PS: Kata® is of course developed according to the latest standards and in compliance with all data protection and cyber security aspects. We think that careful handling and security of patient data is part of modern therapy support.

Author: Dr. Sabine Häußermann

Sources:
[1] Global Initiative for Chronic Obstructive Lung Disease (2022). Global Strategy for the Diagnosis, Management, and Prevention of Chronic Obstructive Lung Disease (2023 report)
[2] Deutsche Atemwegsliga. (2022). Dosieraerosole. Zugriff am 22.12.2022. Verfügbar unter https://www.atemwegsliga.de/dosieraerosole.html
[3] Deutsche Atemwegsliga. (2022). Inhalation mit dem Dosieraerosol. Zugriff am 22.12.2022. Verfügbar unter https://www.atemwegsliga.de/dosieraerosol.html
[4] Hexal. (2022). Arzneimittel richtig anwenden – Dosieraerosol. Zugriff am 28.12.2022. Verfügbar unter  https://www.hexal.de/patienten/ratgeber/arzneimittel-richtig-anwenden/dosieraerosol
[5] Fachklinik Allgäu. Umgang mit Dosieraerosolen. Zugriff am 28.12.2022. Verfügbar unter https://www.fachklinik-allgaeu.de/fileadmin/user_upload/Downloads/Pneumologie_Atemzentrum/BI_Dosieraerosole.pdf
[6] Deutsche Atemwegsliga. (2022). Pulverinhalatoren. Zugriff am 19.12.2022. Verfügbar unter https://www.atemwegsliga.de/pulverinhalatoren.html
[7] Loh, C. H., Peters, S. P., Lovings, T. M., & Ohar, J. A. (2017). Suboptimal inspiratory flow rates are associated with chronic obstructive pulmonary disease and all-cause readmissions. Annals of the American Thoracic Society, 14(8), 1305-1311.
[8] Mahler, D. A. (2017). Peak inspiratory flow rate as a criterion for dry powder inhaler use in chronic obstructive pulmonary disease. Annals of the American Thoracic Society, 14(7), 1103-1107.
[9] Deutsche Atemwegsliga. (2022). Inhalation mit dem NEXThaler.  Zugriff am 19.12.2022. Verfügbar unter https://www.atemwegsliga.de/nexthaler.html
[10] Deutsche Atemwegsliga. (2022). Inhalation mit dem Ellipta.  Zugriff am 19.12.2022. Verfügbar unter https://www.atemwegsliga.de/ellipta.html
[11] Deutsche Atemwegsliga. (2022). Inhalation mit dem Turbohaler.  Zugriff am 19.12.2022. Verfügbar unter https://www.atemwegsliga.de/turbohaler.html
[12] Deutsche Atemwegsliga. (2022). Inhalation mit dem Breezhaler. Zugriff am 22.12.2022. Verfügbar unter https://www.atemwegsliga.de/breezhaler.html
[13] Deutsche Atemwegsliga. (2022). Inhalation mit dem Easyhaler. Zugriff am 22.12.2022. Verfügbar unter https://www.atemwegsliga.de/easyhaler.html
[14] Deutsche Atemwegsliga. (2022). Inhalation mit dem Respimat (Sprühvernebler). Zugriff am 28.12.2022. Verfügbar unter https://www.atemwegsliga.de/respimat.html
[15] Deutsche Atemwegsliga. (2022). Vernebler zur Feuchtinhalation. Zugriff am 28.12.2022. Verfügbar unter https://www.atemwegsliga.de/vernebler.html