An asthma

Asthma

Asthma is the common chronic inflammatory disease of the airways characterized by variable and recurring symptoms, reversible airflow obstruction, and bronchospasm. Symptoms include wheezing, coughing, chest tightness, and shortness of breath...

 spacer is an add-on device used to increase the ease of administering aerosolized medication from a "metered-dose inhaler" (MDI). The spacer adds space in the form of a tube or “chamber” between the canister of medication and the patient’s mouth, allowing the patient to inhale the medication by breathing in slowly and deeply for five to 10 breaths.

Application

After removing the MDI’s cap, the MDI is inserted into the back-piece. The front part of the chamber is closed off by either a facemask that covers both the patient’s mouth and nose, or simply a mouthpiece that goes in the patient’s mouth. To administer the medication, the patient brings the facemask to the face (or the mouth-piece to the mouth) and depresses the metered-dose inhaler once, resulting in the release of one dose of medication. The medication from the MDI is then briefly suspended in the spacer’s chamber while the patient inhales the aerosolized medication by breathing in and out deeply at a slow rate. Some spacers are equipped with a whistle, which sounds as a warning when the patient is inhaling too quickly.

The facemask on the spacer has valves which insure that the medication suspended in the chamber is inhaled by the patient, and that the exhaled breath exits the device through the exhalation valve mounted in the mask. When using a spacer without a facemask, the patient must inhale through their mouth and exhale through their nose. Spacers with facemasks are used in toddlers and young children because that population is unable to coordinate inhaling through the mouth and exhaling through the nose. However, the facemasks are available in small, medium, and large sizes, and spacers with facemasks may also be used in the adult and elderly population.

Modifications

The term spacer is often used to refer to any tube-like MDI add-on device. Some spacers utilize a collapsing bag design to provide visual feedback that successful inspiration is taking place. Another type is transparent plastic in two vase-shaped parts that come together forming a barrel shape.

Benefits

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

Mouth

The mouth is the first portion of the alimentary canal that receives food andsaliva. The oral mucosa is the mucous membrane epithelium lining the inside of the mouth....

 and somewhat more may get into the lung

Lung

The lung is the essential respiration organ in many air-breathing animals, including most tetrapods, a few fish and a few snails. In mammals and the more complex life forms, the two lungs are located near the backbone on either side of the heart...

s. Because of this, less medication is needed for an effective dose to reach the lungs, and there are fewer side effects from corticosteroid

Corticosteroid

Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex. Corticosteroids are involved in a wide range of physiologic systems such as stress response, immune response and regulation of inflammation, carbohydrate metabolism, protein catabolism, blood electrolyte...

 residue in the mouth.

Valve

Valve

A valve is a device that regulates, directs or controls the flow of a fluid by opening, closing, or partially obstructing various passageways. Valves are technically pipe fittings, but are usually discussed as a separate category...

s 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 five and the elderly. It also makes asthma medication easier to deliver during an attack. For this reason, many advise use of spacer.

Disadvantages

A spacer can be bulky, limiting portability. This portability issue is small when one considers the fact that an asthma drug, such as albuterol MDI used with a spacer, is more effective than nebulizers used by EMS and emergency rooms.