SECTION EDITOR Juanita Conkin Dale, PhD, RN, CPNP Children’s Medical Center of Dallas Dallas, Texas
Mikki Meadows-Oliver is Lecturer, Yale University School of Nursing; PNP, Asthma Outreach Program, Yale-New Haven Hospital, New Haven, CT. Nancy Cantey Banasiak is Assistant Professor, Yale University School of Nursing; PNP, Pediatric Primary Care Center, YaleNew Haven Hospital, New Haven, CT. Reprint requests: Mikki Meadows-Oliver, MSN, MPH, CPNP, Yale University School of Nursing, 100 Church Street South, PO Box 9740, New Haven, CT 06536-0740; e-mail: [email protected]
J Pediatr Health Care. (2005). 19, 121123.
Asthma Medication Delivery Devices Mikki Meadows-Oliver, MSN, MPH, CPNP, & Nancy Cantey Banasiak, MSN, APRN, BC, PNP
In pediatrics, asthma is the most prevalent chronic condition. Asthma affects approximately 5 million children under the age of 18 (National Heart Lung and Blood Institute [NHLBI], 2004). Medical management of asthma involves the use of medications that either prevent or reduce airway inflammation or promote bronchodilation of the respiratory smooth musculature. The mainstays of treatment are beta2 agonist, inhaled corticosteroids, and leukotriene modifiers. Improvements in asthma pharmacology have resulted in a variety of ways to deliver the medications. The manner in which a medication is delivered may influence how well it works and the number of side effects experienced. The purpose of this article is to review the most common asthma medication delivery devices prescribed by pediatric nurse practitioners (PNPs) including nebulizers, metered dose inhalers (MDI) with spacer, and dry powder inhalers. An additional aim is to update providers on the recently announced joint evidenced-based guidelines for the selection of aerosol delivery devices developed by the American College of Chest Physicians (ACCP) and the American College of Allergy, Asthma, & Immunology (ACAAI).
0891-5245/$30.00 Copyright © 2005 by the National Association of Pediatric Nurse Practitioners. doi:10.1016/j.pedhc.2005.01.011
Journal of Pediatric Health Care
NEBULIZERS A nebulizer is a device used to change liquid medication into an aerosol particulate form. The
aerosolized medication is then inhaled and deposited into the lung. Either a mask or mouthpiece must be used when using a nebulizer. In order for the medication to work appropriately, it must be deposited in the lower airways. Using blow-by (holding the mask or tubing in front of the child’s face) significantly reduces the amount of medication delivered to the lungs and also increases the chance of intra-ocular deposition of the medication (Pongracic, 2003). Lung deposition of medication from nebulizers has been shown to be 0.5% to 12% (Schuepp, Straub, Moller, & Wildhaber, 2004). Because of the large particle size of most medications, the majority of medication deposition is in the oropharynx and upper airways. An advantage of nebulizer systems over MDIs is that they require no coordination of breathing as do MDIs. The patient inhales and exhales normally until the medication is gone. There are two types of nebulizers: ultrasonic systems and jet compressors. Ultrasonic systems are portable, time-efficient, quiet but expensive. They work by sound vibrations, creating aerosolized medication. Jet nebulizers use a compressor to mix room air and liquid medication instilled in the chamber to provide aerosolized particles. A small compressor delivers high pressure air to the nebulizer, which then transforms liquid medication into mist for inMarch/April 2005
halation by the patient. The jet nebulizers can be small, quiet, and battery-operated or bulky and noisy, requiring electricity. Many insurances and Medicaid may not cover the cost of ultrasonic nebulizers because they have not been shown to be as effective as jet nebulizers (Pongracic, 2003). METERED DOSE INHALERS The metered dose inhaler typically consists of a metal aerosol canister (containing a medication and propellant) in a plastic sleeve with a mouthpiece. The propellants are usually chlorofluorocarbons (CFCs) or hydrofluoroalkanes (HFAs). CFCs have been shown to deplete the ozone layer and their use may be associated with increased health risks including cataracts (Pongracic, 2003). Pharmaceutical companies are in the process of phasing out the use of CFCs in favor of HFAs which have a lower propensity of contributing to global warming. Inhalers that use HFAs as a propellant have a better delivery of medication into the lungs and exhibit more consistent dosing than do MDIs using CFCs as a propellant (Pongracic, 2003). To use an MDI, the patient inhales the medication through the mouthpiece. Many children and adolescents find it difficult to coordinate the timing of the actuation of the MDI and the inhalation of the medication. The patient must exhale fully, inhale, and release the medication at the beginning of the inhalation to draw the medication as fully and as deeply into the lungs as possible. If the inhalation is not timed correctly with the release of the medication, only part of the medication will make it into the airways leading to reduced deposition of medication within the lungs. Some of the medication will be deposited into the back of the mouth and throat instead of the lungs. Inhaling the medication in this manner can lead to side effects such as thrush. The addition of a spacer or holding chamber in conjunction with the MDI dramatically improves treatment effectiveness. Many spacers 122
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are valved, which prevents the escape of medication during use. Spacers, using either a mouthpiece or a mask, increase the proportion of medication particles that reach the lower airways and reduce medication deposition in the oropharynx. Lung deposition of medication when using an MDI with spacer combination ranges from 16% to 42%, with older children achieving greater lung deposition of medication (Schuepp et al., 2004). Pongracic (2003) reports that the electrostatic charge is reduced and drug delivery increased when using plastic spacers after the spacers have been washed with a household detergent and allowed to air dry. DRY POWDER INHALERS Dry powder inhalers (DPI) are becoming a popular alternative to other asthma medication delivery devices. DPIs have the advantage of needing no propellant for medication delivery. However, they rely on the force of the inhalation to get the medication into the lungs. In children from 6 years to 16 years, lung deposition of medication when using DPIs is approximately 29% (Schuepp et al., 2004). Young children and children with severe asthma may be unable to produce enough airflow to use DPIs effectively. DPIs do not need to be shaken and should never be used with a spacer. Children should rinse their mouths after using a DPI, especially if the inhaled medication is a corticosteroid. COMPARISON OF THE DELIVERY DEVICES Based on a systematic review comparing nebulizers to MDIs, Castro-Rodriguez and Rogrigo (2004) reported that nebulizers are more expensive, require a power source, need regular maintenance, and can be variable with respect to the rate of aerosol production. Thus they may be a less preferable way to deliver asthma medications than MDIs. MDIs with valved holding chambers provide a quicker, more cost-effective way to deliver medication. In individuals with moderate to severe
exacerbations, the use of a MDI with valved holding chamber was shown to be more effective in terms of decreasing hospitalizations than the use of the nebulizer when using beta2 agonists. In contrast, Mahoney (2005) reported that for delivering inhaled corticosteroids, nebulizers are better than other methods of medication delivery. The nebulizers are technically not more effective than other asthma medication delivery devices, but because of better compliance and the increased likelihood of correct use they may lead to improved clinical outcomes (Mahoney, 2005). In a systematic review, Brocklebank, Wright, and Cates (2001) compared MDIs and DPIs and reported that DPIs were no more effective at delivering inhaled corticosteroids than were MDIs. Their findings also revealed that, while there were no differences in the effectiveness of medication delivery, MDIs were more cost-effective than DPIs when delivering inhaled corticosteroids. No published studies were found that compared DPIs to nebulizers. GUIDELINES FOR THE SELECTION OF ASTHMA MEDICATION DELIVERY DEVICES In January 2005, the ACCP and ACAAI issued joint evidenced-based guidelines pertaining to the selection of asthma medication delivery devices. The document entitled “Device Selection and Outcomes of Aerosol Therapy: ACCP/ACAAI Evidenced-Based Guidelines” can be accessed at the ACCP Web site (www.chestnet.org). The Web site for the ACAAI is www.acaai.org. The joint evidenced-based guidelines conclude that selection of a medication delivery device should be based on more than the efficacy of the device in delivering medication to the lungs. The selection should include patient-related factors such as age, competence in using the device, and patient preference. Other criteria that should be considered when choosing an asthma medication delivery device inJournal of Pediatric Health Care
clude cost, availability of the device, and convenience. The guidelines further state that health-care providers should provide patients with adequate instructions on using the asthma medication delivery devices because sufficient patient education is crucial to ensuring best possible patient outcomes. CONCLUSION There are multiple medications from which to choose to help children and their families properly treat their asthma. With these multiple medication regimens come myriad medication delivery devices. Pediatric nurse practitioners should be mindful that it is not uncommon for a child with persistent asthma to have to use more than one type of asthma medication delivery device
Journal of Pediatric Health Care
each day. Studies have shown that MDIs appear to be a more cost-effective but not always a more efficient asthma medication delivery system than nebulizers and DPIs. While cost should be taken into consideration, the final decision on what medication delivery device to prescribe should take into account a variety of factors, as discussed in the newly issued evidenced-based guidelines. REFERENCES Brocklebank, D., Wright, J., & Cates, C. (2001). Systematic review of clinical effectiveness of pressurized metered dose inhalers versus other hand held inhaler devices for delivering corticosteroids in asthma. BMJ, 323, 1-7. Castro-Rodriguez, J.A. & Rodrigo, G.J. (2004). Beta-agonists through metered-dose inhaler with valved holding chamber versus nebulizer for
acute exacerbation of wheezing or asthma in children under 5 years of age: a systematic review with metaanalysis. The Journal of Pediatrics,145, 172-177. Cates, C.J., Bara, A., Crilly, J.A., & Rowe, B.H. (2003). Holding chambers versus nebulisers for beta-agonist treatment of acute asthma (Review). The Cochrane Database of Systematic Reviews, 2, (Art. No. CD000052). Mahoney, D. (2005). Nebulizers best for inhaled steroids for asthma. Pediatric News, 39, 5. National Heart, Lung, and Blood Institute (NHLBI) (2004). National Asthma Education and Prevention Program description. http://www.nhlbi.nih.gov/about/naepp /naep_pd.htm Pongracic, J. (2003). Asthma delivery devices: Age-appropriate use. Pediatric Annals, 32, 50-54. Schuepp, K.G., Straub, D. Moller, A. & Wildhaber, J.H. (2004). Deposition of aerosols in infants and children. Journal of Aerosol Medicine, 17, 153-156.