Figure 107-1. Components of pressurized metered-dose inhalers.

—Spacers may be used in patients who can perform a single inhalation and coordinate actuation and inhalation.

—VHCs should be used in patients who have difficulty coordinating actuation and inhalation and/or who use the tidal breathing inhalation technique.

•Drugs commonly used in infants and children include short-acting bronchodilators, anticholinergics, corticosteroids, and corticosteroid long-acting bronchodilator combinations.

•Drugs are formulated as solutions or suspensions.

—Shaking the canister before actuation and actuating the canister right after shaking are critical for drugs formulated as suspensions, such as fluticasone, but not so much for drugs formulated as solutions, such as beclomethasone.

•The use of pMDIs with an incorporated dose counter is very important to decrease the risk of patients using empty inhalers.

•Instruct patients to discard the pMDI when the counter reaches zero.

•If a counter is not available

—For scheduled medications (corticosteroids): Discard the pMDI after 30 days if the total doses per canister were 120 and the drug was prescribed at 2 puffs twice daily.

—For as-needed medications (short-acting bronchodilators): Patients should tally their use.

—pMDI canisters should never be submerged to estimate their fullness.

•Priming and cleaning inhalers: Each device has slightly different directions on how they should be primed prior to use, as well as how often they should be cleaned. Patients and parents should be encouraged to read package inserts for each specific brand.

VHC Procedure

•Verify that there no foreign objects in the VHC.

•Couple the pMDI to the VHC and shake it for at least 5 seconds.

•For each child, 2 decisions must be made.

—Should a mask or mouthpiece be used?

▪There is likely to be greater pulmonary deposition if a mouthpiece is used, but children must be willing and able to cooperate, which requires placement of a mouthpiece past their teeth and closure of their lips around the mouthpiece.

▪Young children, usually <5 years of age, or older children with developmental delays or oral defensive issues, generally do better with a masked holding chamber.

▪It is important to determine which of the 2 techniques is appropriate for each child and to recognize that the optimal technique may change as a child grows older.

▪In general, the tidal breathing technique is appropriate for children <5–8 years of age, and the single-breath technique (which usually results in greater pulmonary deposition) is optimal for older children. The single-breath technique should be used when possible.

•Most young children should use a masked holding chamber with the tidal breathing technique, and most older children should use a holding chamber with a mouthpiece and the single-breath technique. However, there are exceptions. Some children may be able to master the use of a mouthpiece but must use tidal breathing, and some children may tolerate the treatment better when a mask is used, even at an older age, but they can properly perform the single-breath technique.

•The use of a mouthpiece is preferred to a face mask because it decreases oculofacial deposition and increases the amount of drug available for inhalation.

•The single-breath technique is preferred to the tidal breath technique because it increases lung deposition.

•Regardless of which inhalation technique is chosen, if there is a substantial delay between actuation and inhalation, pulmonary deposition will be reduced, as more medication deposits on the walls of the VHC. If using the tidal breathing technique, this delay is minimized if the child starts breathing before the inhaler is actuated.

•Delay between shaking and actuating the pMDI could result in variability of the inhaled dose of drug formulated as suspension.

Tidal Breathing Technique

•Gently place the mask against the face or insert the mouthpiece in the mouth, ensuring a good seal.

•Encourage the child to breathe quietly and normally for a few seconds before actuation and for at least 4–6 breaths after each spray.

Single-Breath Technique

•Instruct the child to exhale to the end of a normal breath.

•Insert the mouthpiece into the mouth, past the teeth, and instruct the child to close the lips around the mouthpiece to maintain a good seal.

•Immediately after each actuation, many children will be tempted to breathe in too quickly. Ideally, they will learn how to take a slow, deep breath all the way, until they can’t breathe in any further.

•Many VHCs with a mouthpiece have a flow signal. If the chamber whistles, the patient is breathing in too quickly.

•Repeat the process for any additional prescribed actuation.

Soft-Mist Inhalers

•SMIs deliver more drug than pMDIs, especially at lower tidal volumes.

•SMIs release propellant-free aerosols (tiotropium).

•The speed of the aerosol is tenfold slower than the pMDI.

•The aerosol cloud lasts in suspension threefold longer than the pMDI.

•The device is marketed for use without a VHC. However, a patient who can’t or won’t perform the recommended inhalation technique should use a VHC.

•The only drug that currently has a U.S. Food and Drug Administration– approved pediatric indication is tiotropium (for asthma, ≥12 years of age).

—A device that combines albuterol and ipratropium bromide is also commercially available but is marketed for treatment of chronic obstructive pulmonary disease.

•Devices need to be discarded 90 days after opened.

•The device has a dose indicator that turns red when 7 of 30 doses are available.

•Priming and cleaning are also necessary, just as in pMDIs. Patients and parents should be reminded to read all package inserts, as recommendations vary from brand to brand.

SMI Procedure

•Turn the base of the device clockwise until it clicks.

•Open the cap that covers the mouthpiece.

•Release the aerosol.

—Exhale fully.

—Close the lips around the mouthpiece.

—While keeping the device in a horizontal position, begin to breathe slowly and press the dose-release button.

—Do not block the lateral opening present in the mouthpiece.

—Once inhalation is completed, a 5- to 10-second breath hold is suggested.

Resources for Families

•MDIs are the most commonly used inhalation devices in children with asthma and have many advantages over small-volume nebulizers, even in very young children.

•They are more portable and are quick and easy to use, and many more medications are available in this form.

•Proper inhalation technique is critical for success and should be reviewed at each visit.

•Parents must be reminded of the importance of not using an empty MDI. Use of pMDIs with counters is preferred.

•Since most children with asthma use both controller and reliever MDIs, it is easy and common for patients and parents to confuse the two. Some specialists suggest placing easily read labels, in the parent or child’s primary language, on each inhaler (controller or reliever).

•Verification of correct inhaler technique should occur at each visit if possible.