by Jill Heins-Nesvold, MS, National Senior Director, Health Systems Improvement and Indoor Air Quality, American Lung Association
WHAT IS THE PROBLEM?
Inhaled aerosol therapy remains the cornerstone of asthma and COPD (chronic obstructive pulmonary disease) treatment. While efficient and user-friendly medication delivery devices are available, incorrect inhaler technique limits the deposition of medication.
A review of 2,123 asthma patients by the National Services for Health Improvement found that, without training, 86% failed to properly use their inhaler (1). Another study showed that only 1 out of 10 patients was able to perform all essential metered dose inhaler (MDI) steps correctly (2).
Common errors in the use of MDIs:
- No exhalation prior to actuation.
- Lack of coordination between actuation and inhalation.
- Stopping inhalation when the cool spray hits the back of the throat.
- Not holding breath long enough (5-10 seconds) after inhalation.
Medication blasts out of an MDI at very high speeds—up to 60 mph. If you’re using an MDI without a valved-holding chamber, up to 80% of the medication lands on the face, tongue and back of the throat. This leaves little medication deposited into the lungs.
HOW CAN A VALVED-HOLDING CHAMBER HELP?
A valved-holding chamber (VHC) acts as an aerosol reservoir, allowing patients to actuate the MDI and then inhale the medication in a two-step process. This reduces the need to coordinate actuation and inhalation at the same time.
The VHC’s one-way valve traps and holds the medicine, giving patients time to take a slow, deep breath and breathe in all the medicine. Use of VHCs can improve MDI medication delivery to the lungs, reducing oropharyngeal deposition and helping patients overcome challenges in coordinating MDI actuation with inhalation.
How VHC Design Can Impact Performance
The design of the VHC can have an impact on its performance in two ways: electrostatic charge and volume.
Some plastic VHC devices have an electrostatic charge or may build up an electrostatic charge within the chamber. This build-up may attract drug particles to the chamber walls and reduce drug delivery to the lungs. Drug delivery through the use of antistatic VHCs can provide improvement in bronchodilator response during acute, reversible bronchospasm.
Large-volume holding chambers increase lung deposition to a greater degree than tube spacers or small holding chambers. Currently available VHCs range in volume from 50 ml to 750 ml. VHCs with small volumes (150 to 250 ml) have not been shown to be as effective as those with large volumes (750 ml). Larger volume VHCs may be less portable for children and teens. Smaller volume sizes are generally more effective for infants and small children, as they require fewer tidal breaths to empty.
FREQUENTLY ASKED QUESTIONS ON VALVED-HOLDING CHAMBERS
Which patients benefit the most?
A VHC is needed for all MDIs, regardless of whether the medication is a reliever or maintenance/controller.
How are they prescribed?
A prescription is needed to dispense a spacer or VHC. It is best if the provider is more explicit than “dispense spacer.” Otherwise, what the patient may receive is anything from a VHC to a piece of cut blue tubing to a disposable cardboard spacer. Cut blue tubing or a disposable piece of cardboard will not provide an effective separation between the MDI and the patient to improve coordination, reduce medication speed and ensure deposition of the medication into the lungs. Being explicit on each prescription for a VHC will ensure patients receive the most evidence-based, effective tool.
Both spacers and VHCs are considered durable medical equipment. Therefore, a separate prescription and patient co-pay are needed. Only pharmacies with a durable medical equipment license can secure and dispense VHCs. Providers may need to explain this to patients to avoid confusion.
Are they covered by insurance?
Currently in Minnesota, all health plans provide coverage for spacers and VHCs. However, health plans may only cover one VHC per year. This may cause problems for patients who divide their living time between two homes and who would benefit from the ability to have a VHC at home and school (or daycare).
How can clinicians support patients in proper use?
Ongoing patient education is a critical factor of correct inhaler technique, adherence and disease control.
Tips for improving how patients use inhalers:
- Check patient inhaler technique often.
- Keep devices consistent when changing or adding medications—try not to mix MDI and DPI (dry powder inhaler) devices. Each new pairing of MDI and VHC requires instruction specific to the devices being used.
- Use training aids for encouraging proper technique of inhalers. The American Lung Association has numerous videos to instruct patients on proper delivery device use.
- Ensure well-fitting VHCs are used with MDIs by infants and children and by patients with poor coordination or inhaler technique.
- Prescribe an antistatic VHC to prevent loss of medication to chamber walls.
- Instruct patients (and caregivers) to clean VHCs at least weekly.
View a quick reference guide from the American Lung Association on proper inhaler technique.
REFERENCES
- Hardwell A, Barber V, Hargadon T, et al. Technique training does not improve the ability of most patients to use pressurized metered-dose inhalers (pMDIs). Prim Care Respir J. 2011;20(1):92-6.
- Restrepo, RD, Alvarez MT, Wittnebel LD, et al. Medication issues in patients treated for COPD. Int J Chron Obstruct Pulmon Dis. 2008;3(3):371-84.
