Spacer devices for metered dose inhalers.

Area of Science:

• Respiratory medicine
• Pharmacology
• Medical devices

Background:

• Pressurized metered dose inhalers (pMDIs) are widely used for respiratory drug delivery.
• Spacer devices, including tube spacers and holding chambers, attach to pMDI mouthpieces.
• These devices aim to improve drug deposition in the lungs and reduce side effects.

Purpose of the Study:

• To evaluate the role and effectiveness of spacer devices in conjunction with pMDIs.
• To assess the impact of spacers on medication deposition, coordination, and clinical outcomes.
• To explore the utility of spacers in specific patient populations and clinical scenarios.

Main Methods:

• Review of existing literature on pMDI spacer devices and their clinical applications.
• Analysis of studies comparing pMDI use with and without spacers.
• Examination of factors influencing spacer performance, such as volume and electrostatic charge.

Main Results:

• Spacers minimize coordination issues, reduce oropharyngeal deposition, and often enhance lung deposition compared to pMDIs alone.
• Clinical benefits may be more pronounced in patients with poor pMDI technique or in severe acute asthma/COPD.
• Large volume spacers can be a viable alternative to nebulizers for high-dose bronchodilator delivery.
• Controlling electrostatic charge on plastic spacers is vital for optimal performance.

Conclusions:

• Spacer devices are valuable adjuncts to pMDIs, particularly for improving lung deposition and reducing side effects.
• Their use is recommended for young children and in situations requiring reduced systemic corticosteroid bioavailability.
• While not universally required, spacers offer significant advantages in specific clinical contexts and patient groups.