Asthma spacer

An asthma spacer is a type of add-on device used by an asthmatic person to increase the effectiveness of a metered-dose inhaler. Such add-on devices include spacers, which merely add space between the mouthpiece of the metered-dose inhaler (MDI) and the patient's mouth, as well as holding chambers, which have valves that result in the aerosol from the MDI being briefly held in a reservoir from which the patient subsequently inhales the aerosolized medication. The term spacer is often used to refer to any tube-like MDI add-on device, including holding chambers. Spacers are specially designed plastic or metal tubes, although they can be made from any suitable container, e.g. polystyrene cups or plastic bottles. [cite web | title = Home-made spacers for bronchodilator therapy in children with acute asthma: a randomised trial |url = http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=PubMed&list_uids=10501359&dopt=Abstract | work = The Lancet | accessdate = 2008-06-09 ] [cite web | title = Asthma inhaler spacers | url = http://www.appropedia.org/Asthma_inhaler_spacers | work = [http://www.appropedia.org Appropedia] | accessdate = 2008-06-09] The inhaler fits on one end, while the patient breathes normally on the other. Some spacers utilize a collapsing bag design to provide visual feedback that successful inspiration is taking place.

Benefits of a spacer

In order to properly use an inhaler without a spacer, one has to coordinate a certain number of actions in a set order (pressing down on the inhaler, breathing in deeply as soon as the medication is released, holding your breath, exhaling), and not all patients are able to master this sequence. Use of a spacer avoids such timing issues. Spacers slow down the speed of the aerosol coming from the inhaler, meaning that less of the asthma drug impacts on the back of the mouth and somewhat more may get into the lungs. Because of this, less medication is needed for an effective dose to reach the lungs, and there are fewer side effects from corticosteroid residue in the mouth. [Merck Manual 18th ed. p. 405]

Valves on a spacer (which technically makes it a holding chamber) cause the patient to inhale the contents of the spacer, but exhalation goes out into the air. The problem of co-ordinating an inspiration with a press of an inhaler is avoided, making use easier for children under 5 and the elderly. It also makes asthma medication easier to deliver during an attack.

pacer Disadvantages

* A spacer can be bulky, limiting portability.
* Devices along the inhalation path - such as a spacer - may cause the medication to deposit prior to reaching the patient and the patient can receive less than the measured dose.

References