Several types of aerosol delivery technology exist on the market today, but depending on the specific disease being treated, certain devices may make more sense for patients.
EDITOR’S NOTE: Article updated May 1, 2016 to correct comments attributed to Kevin Johnson, RRT-NPS, regarding large volume nebulizers. RT magazine regrets the error.
Patients that require some form of aerosol medication to manage their conditions have a variety of delivery systems from which to choose. Although all of them have advantages, certain devices might offer optimal outcomes, depending on patient preference and disease.
The term “nebulizer” is used to describe both the compressors that deliver treatments and a broad range of the “cups” into which the medication goes, according to Stu Novitz, vice president of Sales and Marketing at B&B Medical Technologies. “Within the cups there is a wide variety of categories: small volume, large volume, continuous and subcategories within the categories.”
Large Volume Nebulizers
Kevin Johnson, RRT-NPS with B&B Medical, explained that large volume nebulizers, such as the company’s Hope nebulizer, don’t require refilling as often as the small volume devices and deliver more than 60% of particles in the respirable range at 10 LPM flow.
“You usually use them for 24 to 48 hours due to the acuity of the disease being treated. They are used in the ER, during transfer and in the ICU,” he said, noting that the Hope nebulizer is driven by a medical air/oxygen gas source.
Johnson pointed out that Heliox added to the auxiliary port increases the number of particles within the respirable range from 64 to 78% and allows for maximum nebulization and mixing of the Heliox gas. “Heliox reduces the turbulence in the airways,” Johnson said.
Furthermore, continuous use means that the patient also receives continuous oxygen therapy. “With small volume, you have to pull the device off the patient every ten minutes, interrupting the oxygen to the patient,” Johnson added.
Breath Actuated Devices
For the last 30-plus years, nebulizers have been the device of choice for most aerosol delivery in the United States, according to William Seitz, MBA, vice president, Sales and Marketing, Monaghan Medical Corp. He asserted that the technology has predominantly remained the same, but most nebulizer devices lack evidence-based science and he advised clinicians to consider other options.
Seitz pointed out the biggest design flaw of continuous nebulizers is that they produce drug therapy constantly, regardless of the patient’s breathing pattern and only as long as the medication lasts. “But patients don’t breathe in continuously,” Seitz said. For instance, patients with chronic obstructive pulmonary disease (COPD) have highly variable I:E ratios and may spend relatively short time inhaling; so a continuous delivery system doesn’t make sense when the clinical objective is to ensure predictable, adequate dosing. Rather, a breath-actuated nebulizer (BAN) may be more effective as it only delivers aerosolized medication during the inhalation phase, which is triggered by patient. Breath-actuated technology has been a major advance in aerosol delivery.
Research supports Seitz’s assertion. A 2012 study1 evaluated nebulized drug delivery for obstructive lung disease via BAN versus conventional nebulizer. Subjects were randomly assigned to either AeroEclipse II or standard nebulizer. At the conclusion of the study, 54% of subjects indicated that BAN performed better than the conventional nebulizer; 68% preferred treatment duration with BAN, which was 4.1 min vs. 9.9 min (P < .001) with the conventional nebulizer. BAN was also associated with fewer adverse events.
Seitz cited another 2012 study2 out of Chesapeake Regional Medical Center that found average treatment-to-effect was accomplished in one-third the time with BAN. Also, admissions for COPD and asthma decreased from 65.94% to 36.7% and 5.71% to 1.6%, respectively. Additionally, since treatments were reduced from every four hours to every six, the facility realized an estimated savings of $73,000.
Mouthpiece vs Facemask
Lisa Cambridge, MSHS, RRT, director, Medical Science and Pharmaceutical Alliances at Pari Respiratory Equipment, reported drugs delivered by nebulizer can be administered by mouthpiece or facemask, but explained that evidence suggests that a mouthpiece is often more effective and preferable over the facemask.
Although most patients can use a mouthpiece by age four, it may not be appropriate for babies, toddlers and some elderly patients “Babies and toddlers lack sufficient understanding to properly use a mouthpiece and some patients may be unable or unwilling to use it. A facemask is a suitable alternative in those situations,” she said.
Recently, more attention has been given to the influence of the patient interface on the overall efficiency of the delivery system, according to Cambridge. Pari’s Bubbles the Fish, a front-load mask is specifically designed to optimize drug delivery. “Inhaled corticosteroids and anticholinergics drugs can cause adverse effects if they get into patients’ eyes,” Cambridge said. “The Bubbles mask directs aerosol toward the mouth and away from the eyes and face.
Studies demonstrated increased drug delivery to the lungs and a significant reduction in deposition to the eyes and face, which may mitigate risk for local side effects. It’s more efficient than traditional bottom-load designs.” Bottom-load masks deposit more aerosol in the mask, reducing its efficiency.
Compatibility between the device and patient interface is another important consideration. “For example, the Pari Smartmask is the only mask recommended by Pari for the eFlow Technology devices, Altera Nebulizer System and eRapid Nebulizer System. The Pari Smartmask is a close-fitting, soft mask with an exhalation valve designed to work specifically with the inspiratory valves in the nebulizer handset,” she said.
Cambridge asserted that clinicians should note patient preference when deciding which delivery system and interface to use. “If a patient is more willing to use their preferred device and interface, it could help promote treatment adherence.”
Facemasks are widely used in the pediatric population in both the home and clinical setting. However, delivering aerosol drugs to pediatric patients can be quite challenging. Cambridge pointed out that children may be uncooperative during aerosol therapy and crying can significantly reduce drug delivered to the lungs. “There are various pediatric masks and devices in the marketplace today to promote treatment cooperation in young children. However, without clinical data it is difficult to know if they are efficient,” she said.
An alternative technique sometimes used with uncooperative children is “blow-by.” Cambridge explained that the caregiver waves the nebulizer a slight distance from the child’s face. “Studies have found this method inefficient, significantly reducing the medication dose to the patient. Much of the aerosol goes into the air,” she said. “However, newer published evidence suggests that blow-by may provide adequate aerosol delivery when using a specific nebulizer/mask combination.”
A study3 that tested blow-by technique with the Pari LC Sprint Nebulizer and Bubbles the Fish Mask demonstrated that this combination delivered substantial amounts of drug, even at a distance of 4 cm, compared to other nebulizer/ mask combinations.
According to Mitchell Yoel, MPT, executive vice president of Business Development at Drive | Devilbiss Healthcare, clinical data has shown the best deposition is achieved via a Metered Dose Inhaler (MDI) when used with proper technique, which involves slow inhalations with a five-second breath hold. However, data also states that small volume nebulizers (SVN) can be equally as effective with proper technique, which incorporates slow tidal volume breaths with a breath hold every couple of breaths. However, the optimal delivery device will depend on the ability of the DME provider to match device benefits with individual patient needs, noted Yoel.
Both MDI’s and SVN’s have been shown to be equally effective in delivering medications, so the choice of either device should not depend on a medical condition. “The decision is sometimes determined by which medication would best treat a medical condition and the type of delivery method available,” Yoel said. “Certain aerosol medications are only available in MDI, Dry Powder Inhaler (DPI) or SVN form. Combo drugs such as Advair, Symbicort, and Dulera are indicated to prevent asthma attacks, and are only available in DPI or MDI form.”
Rescue medications, like Albuterol, should be delivered via MDI since the patient has easy access to the medication and does not need a nebulizer compressor to deliver the drug; the patient must be able to use an MDI correctly to achieve maximum results, Yoel said. Manufacturers have developed portable nebulizers that are smaller, lighter and battery operated, making it more convenient for patients to receive a SVN treatment outside of the home.
However, certain medical conditions are best managed with nebulizer delivery, such as an exacerbation of COPD or asthma. “These types of patients generally will not be able to perform a breath hold needed for an effective MDI treatment,” Yoel said, adding that nebulizer therapy would also benefit patients with reactive airway disease compounded with a neurological disorder affecting their dexterity and coordination, such as ALS, MS, or Parkinson’s.
Spacers and Chambers
Pressurized metered dose inhalers (pMDIs) often use spacers and valved holding chambers (VHCs) to improve the targeting of aerosolized medications to the lungs and reduce local side effects, according to Simon McGuire, general manager, Philips Respiratory Drug Delivery. “The inspiratory valve is a low-resistance, low dead-space, duck-billed valve, designed to minimize any impediment to air flow, which might otherwise lead to high levels of local aerosol deposition,” he said. “The exhalation valve allows comfortable exhalation and reduces rebreathing. This is a particular concern in infants. Bench testing conducted using adult, pediatric and infant breathing patterns demonstrated that both of these valves open freely, especially when using low pediatric pressures and flow rates.”
In addition to device design, clinicians need to be aware of electrostatic charges created during the manufacturing process. “Electrostatic interactions occur when the charged aerosol drug particles enter the VHC and are attracted to the sides of the chamber wall, reducing the available amount of medication that may be delivered to the patient. When we couple this process with patient user errors— such as inhalation delays—the amount of drug that is available for inhalation is reduced further,” said McGuire. “The use of anti-static material in the construction of a VHC reduces electrostatic interactions and allows the aerosol to be suspended longer, which increases the available dose and consistency for delivery to the patient’s lungs.” A 2014 study4 supports McGuire’s statement: To derive optimal results from aerosol delivery, the method of choice should take in to consideration performance, adherence and patient preference. RT
Phyllis Hanlon is a contributing writer to RT. For further information, contact [email protected]
Arunthari V, Bruinsma RS, Le AS, Johnson MM. “A prospective, comparative trial of standard and breath-actuated nebulizer: efficacy, safety, and satisfaction.” Resp Care. Aug 2012;57(8):1242-7. doi: 10.4187/respcare.01450. Epub 2012 Feb 17.
Saunders DN. “Transitioning to a breath-actuated pneumatic nebulizer in the emergency department and in-patient settings: experience gained from stakeholders involved with the process.” (Poster presented at 2015 AARC)
Mansour MM, Smaldone GC. “Blow-by as potential therapy for uncooperative children: an in-vitro study.” Resp Care. Dec 2012; 57(12); 2004-2011. doi: 10.4187/respcare.01653.
Nikander K, Nicholls C, Denyer J, Pritchard J. “The evolution of spacers and valved holding chambers.” Journal of Aerosol Medicine and Pulmonary Drug Delivery. Supplement 1, 2014. S-4-S-23; (27). doi: 10.1089/jamp.2013.1076.