What is a defining characteristic of pneumatic (jet) nebulizers?

A defining characteristic of pneumatic (jet) nebulizers is that only a limited percentage of the medication reaches the lower respiratory tract, typically around 10%. This is primarily due to the mechanics of how these nebulizers operate. They create a fine mist from liquid medication by using compressed air or oxygen that passes through a small jet, atomizing the medication. However, the particles produced can be too large or the flow of air can lead to deposition in the upper airways rather than reaching deeper into the lungs.

Understanding this characteristic is important for respiratory care practitioners who need to optimize medication delivery and patient outcomes. Recognizing that much of the medication may not reach the intended site helps in discussing treatment strategies with patients and in making informed choices about therapy plans.

The other options describe different features not associated with pneumatic nebulizers. For instance, they are not typically electrically powered, they do not use cold freon as a delivery method, and they do not require hand-breath coordination for operation; instead, they function independently of the patient's breathing technique, which distinguishes them from other nebulization methods like metered-dose inhalers.