Optimized Overview of Valved Holding Chambers (VHCs) and Spacers

Valved holding chambers (VHCs) and spacers are essential tools for optimizing the delivery of inhaler medications. They extend the inhaler’s mouthpiece, directing the medication cloud more effectively toward the throat and reducing the amount of medication wasted in the air or stuck in the mouth.

A spacer does not suspend the medication, so coordination between breathing and actuating the metered-dose inhaler (MDI) is still necessary. In contrast, a VHC uses a one-way valve to trap and suspend the medication, allowing it to be inhaled gradually over a few seconds. VHCs come with or without masks, suitable for patients from infants to adults.

Why Valved Holding Chambers Are Important

Inhaled medications aim to target inflamed airways, but their effectiveness depends on the user’s ability to position and activate the MDI at the right moment. This requires starting a slow, deep inhalation just before depressing the inhaler. However, when the medication is released from the inhaler at speeds of around 60 miles per hour, a significant portion can be lost to the air, or deposited on the tongue, throat, or sides of the mouth before reaching the lungs.

Spacers built into MDIs (such as Aerospan) are FDA-approved as a single unit, while add-on spacers require the MDI canister to be removed and inserted into a special port. The performance of these add-ons can vary. On the other hand, VHCs are equipped with a universal rubber end piece that fits the MDI without removing the canister, ensuring it functions as intended by the manufacturer and approved by the FDA.