Are Wet Nebulizers Better Than Metered-Dose Inhalers?

There has been a longstanding belief among some that wet nebulizers work better than metered-dose inhalers (MDIs) when it comes to treating lung diseases like COPD. It may seem a fair assumption given that you can use nebulizers for longer periods of time, but does longer necessarily mean better?

An MDI is a plastic and metal device that delivers a specific amount of aerosolized medication that is inhaled directly into the lungs. MDIs are commonly used to treat asthma, COPD, and other respiratory illnesses. A device called a spacer catches the mist as it leaves the device and allows you to take in more medication. And with a spacer attachment, you don't have to worry about coordinating your breath with each puff, and there is far less irritating residue left in the mouth.

By contrast, the nebulizer is an electronic device that transforms liquid into a very fine mist which is then inhaled into the lungs. Like an MDI, nebulizers are used to treat respiratory conditions such as asthma and COPD. This type of device requires that you measure the amount of medication needed which is then poured it into a cup attached to the nebulizer tubing.

Compared to MDIs, nebulizers often seem to be the device of choice in hospitals and for good reasons. They are easy to use, can be quickly adapted (to accommodate a mouthpiece, mask, tracheostomy collar, or endotracheal tube), and can deliver a host of different medications simply by pouring the drug into the device.

And, while proper technique is important for both devices, the general consensus is that there is more room for error when it comes to using the MDI. In fact, one study showed that only five percent of patients used an MDI correctly.

The overriding perception that nebulizers work better than MDIs may coincide with the duration of inhalation. You can, for example, use a nebulizer for up to 20 minutes compared to the MDI for which you only receive a few, quick puffs over the course of seconds. As such, it would seem reasonable that you are getting more medication with a nebulizer. And more is better, right?

In 2002, wet nebulizers were regarded as the first-line treatment of choice for people with acute asthma in hospital emergency rooms. This changed in 2003 when studies began to suggest that MDI use associated with a significant reduction in length of emergency room stays.

Subsequent research largely supported these findings, concluding that persons treated with MDI were typically released within the first two hours of treatment. Although the percentage of successful emergency room discharges were similar in both groups, individuals treated with MDIs were shown to improve faster when compared to nebulized patients.

Another study showed that MDIs with spacers were associated with fewer side effects, as well, namely drug-induced anxiety and tremors. From a consumer standpoint, the devices are also known to be less expensive. So while some may say nebulizers deliver more medication, research suggests it offers no added clinical benefit when compared to MDIs.

Both nebulizers and MDIs have their advantages and shortcomings, both real and perceived. If one device has been working for you just fine and you have mastered the proper technique, there is really no need for change other than cost.

And even if the price is an issue, it is often better to explore ways to trim the cost of nebulizer treatment (through mail-order prescription plans and drug assistance programs) than to change to a device which may not work as well for you as an individual.

Moreover, if you aren't getting the benefit you think you should from your current device, don't assume that it's the product at fault. Speak with your doctor and see if there are things you can do to improve how you use the device. This is especially true for MDIs which are prone to user error.