Small-Volume Nebulizers
Ariel Berlinski, MD, FAAP
Introduction
•Nebulizers convert a solution or suspension into an inhalable mist with the aid of a gas source.
•Many parents mistakenly refer to the required air compressor as the “nebulizer.”
•Drugs usually delivered in pediatric patients include short-acting bronchodilators, anticholinergics, corticosteroids, epinephrine, and antibiotics.
•This platform is used for the off-label use of many drugs.
•The advantages and disadvantages to the use of nebulizers are shown in Box 106-1.
Box 106-1. Advantages and Disadvantages of the Use of Jet Nebulizers
Advantages | Disadvantages |
Easy technique (tidal breathing) | Bulky, less portable than other systems |
Can use at any age | Longer treatment times |
Can use with any disease severity | Require cleaning and disinfection |
Use with artificial airways | Noisy (may disturb infants) |
High doses possible (ie, antibiotics) | Require a power source |
Inexpensive | High variability between brands |
Modified from Geller D, Berlinski A . Aerosol delivery of medication . In: Light MJ, Homnick DN, Schechter MS, Blaisdell CJ, Weinberger MM, eds . Pediatric Pulmonology. Elk Grove Village, IL: American Academy of Pediatrics; 2011 .
Types of Small-Volume Jet Nebulizers
•Small-volume jet nebulizers typically have a loading capacity lower than 10 mL.
•There are 3 main types of small-volume jet nebulizers (Figure 106-1).
—Continuous output
—Breath enhanced
—Breath actuated
•Continuous-output jet nebulizers are the most commonly used because of their low cost and widespread availability.
—They generate and release aerosol during inspiration and expiration, thus generating large aerosol waste and exposing the caregivers.
—Adding a 15-cm corrugated tube distal to the patient increases drug delivery (reservoir effect).
—Disposable units should not be reused.
•Breath-enhanced nebulizers also generate and release aerosol during inspiration and expiration but increase their output during inspiration by means of air entrainment facilitated by one-way valve systems.
—Verify that the patient can open the valve and take advantage of the increased efficiency.
•Breath-actuated nebulizers deliver medication only during inspiration.
—Some devices are a modified form of continuous-output jet nebulizer with a one-way valve and a reservoir that is filled during expiration.
—Other devices have a spring-loaded one-way valve and produce aerosol only during inspiration.
▪Treatments will be longer, and either dose or treatment time might need to be reduced to avoid overdosing.
—Verify that the patient can open the valve and take advantage of the increased efficiency.
Figure 106-1. Examples of nebulizers.
•Compressors are used for home care; they generate a low and fixed flow at a low pressure.
—Compressors lose efficiency over time, so ask the patient if the treatment is taking longer than usual.
—Air filters used in the compressor need to be changed periodically.
•Central oxygen or air is typically used at institutions; the gas is delivered at high pressure, at an adjustable flow rate.
—Treatments are short and have more particles that are likely to be deposited in the lungs.
Using the Nebulizer
Tips for Patients Using Nebulizers
•Tapping the nebulizer cup increases drug delivery.
•Use of single-dose vials is recommended because the use of a multidose containers has been associated with infection.
•Drug output markedly decreases after sputtering begins.
—Instruct the patient to stop the treatment after sputtering begins.
•The solution or suspension left in the nebulizer after a treatment is complete is called residual volume.
—It varies from 0.5 to 2.2 mL, depending on the nebulizer model.
—Increasing the loading volume to 4 mL will improve drug output of those devices with high residual volume but will also increase treatment time.
—Decreasing loading volume could result in minimal drug output.
▪Consider decreasing treatment time as a strategy for decreasing the delivered dose.
—Instruct the patient to maintain the nebulizer in the upright position.
Interface and Inhalation Technique
•While there may be less pulmonary deposition of medications when using a face mask instead of a mouthpiece, this difference is unlikely to have a significant clinical effect.
•Use of a face mask generates facial and ocular exposure.
—Dermatitis has been reported with the administration of corticosteroids.
—Anisocoria has been reported with the administration of anticholinergics.
•Most specialists suggest that children use a mouthpiece as soon as he or she can create a good seal.
—Poor seal of the face mask markedly reduces lung delivery.
—Blow-by technique is very inefficient and should be avoided.
—Front-loaded face masks are more efficient than bottom-loaded face masks, especially when the seal is not tight (Figure 106-2).
Figure 106-2. Examples of face masks used with small-volume nebulizers.
•Do not occlude the holes in the face mask, because doing so does not increase drug delivery and can result in rebreathing CO2.
•Some masks and interfaces favor transnasal delivery. This could be an alternative for patients <18 months of age (obligate nose breathers).
•Since crying markedly reduces intrapulmonary deposition, patients might require desensitization to get them accustomed to using the mask.
•Instruct the patient to breathe slowly and deeply when possible.
•Instruct the patient to take his or her medication in the sitting position, when possible.
Cleaning
•Cleaning the nebulizer is important to prevent the device from malfunctioning.
•The tubing that connects the nebulizer and the compressor should not be submerged in water.
•Vinegar solutions are ineffective at killing Pseudomonas aeruginosa.
•After each use
—Perform proper handwashing.
—Disconnect the nebulizer from the tubing and disassemble the nebulizer.
—Clean the nebulizer, mouthpiece, and mask with water and dish detergent.
—Remove any visible secretions.
—Rinse the nebulizer, face mask, and mouthpiece with sterile water, which can be prepared by boiling tap water for 5 minutes.
—Place the nebulizer on an absorbent towel to air-dry before storing it.
Disinfection
•Disinfecting the nebulizer is important to avoid contamination of the device.
•Once a day, after cleaning is completed, perform disinfection with any of these methods.
—Cold methods
▪Soak the nebulizer and parts in either
~70% isopropyl for 5 minutes
~3% hydrogen peroxide for 30 minutes
▪Then, rinse it off with sterile water.
—Heat methods (if recommended by the manufacturer)
▪Soak the nebulizer and parts in boiling water for 5 minutes.
▪Microwave the device while submerged in water in a microwave-safe receptacle for 5 minutes.
▪Wash the device in a dishwasher for 30 minutes, if the water is at least 70°C (158°F).
▪Use an electric steam sterilizer.
—After the disinfection
▪Remove excess water.
▪Place the nebulizer on an absorbent towel to air-dry before storing it.
Other Types of Nebulizers
•Ultrasonic nebulizers
—Should not be used to deliver budesonide or other medications that may be degraded by the heat generated.
•Vibrating mesh nebulizers
—These are very efficient.
—They are faster than jet nebulizers.
—They generally have very low residual volume, which means a higher proportion of medication will be delivered to the patient. This is not so important with bronchodilators but may be important for delivering drugs with a narrow therapeutic index.
—Cleaning of the device (mesh) is crucial for optimal performance.
—The mesh is periodically replaced.
—These devices are very expensive.
—Many devices are prescribed as a drug-device combination of mesh nebulizers.
▪Aztreonam-Altera (PARI Pharma, Starnberg, Germany) for the treatment of P aeurugina infection in patients with cystic fibrosis
▪Iloprost–I-neb (Philips, Amsterdam, Netherlands) for the treatment of pulmonary hypertension
•How to Use a Nebulizer (Medline Plus). medlineplus.gov/ency/ patientinstructions/000006.htm
•A Patient’s Guide to Aerosol Drug Delivery (American Association for Respiratory Care). www.aarc.org/wp-content/uploads/2014/08/aerosol_guide_patient.pdf
Clinical Pearls
•Inhalation technique and equipment maintenance should be frequently reviewed.
•Ask the patient whether the length of therapy is increasing, since this could represent compressor malfunction.
•If the patient uses a vial dose and the dose needs to be decreased by half, a half-vial dose should be mixed with same volume of normal saline solution so the final volume remains the same.
•Don’t use an ultrasonic nebulizer to deliver corticosteroid suspensions.