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Nebulization, Coupage, and Respiratory Therapeutics 1135

Equipment, Anesthesia Possible Complications and turn recumbent patients side to side every
Three types of nebulizers: Common Errors to Avoid 2 hours to aid in mobilization of airway
VetBooks.ir pressure to generate the aerosol. Jet flow rate • Bronchoconstriction: most common and Early ambulation:
Nebulization and coupage:
secretions.
• Jet nebulizers: employ oxygen under high
serious side effect. Using drug formulations
• Assist and encourage patients to ambulate,
determines the rate of droplet generation
and the droplet size distribution.
• Ultrasonic nebulizers: the aerosol is produced not made for aerosolization increases the even for short distances. In the author’s
experience, this is essential to the success-
risk. Pretreatment or concurrent use of a
by the vibration of a piezoelectric crystal. bronchodilator may reduce the risk. ful treatment of pneumonia in recumbent,
Frequency and vibration amplitude deter- • Environmental waste: many nebulizers will large-breed dogs (e.g., wolfhounds).
mine drug output and droplet size. continuously aerosolize drug even if the Thoracic wall percussion/vibration:
• Vibrating mesh nebulizers: use a mesh or patient is not inhaling, allowing drug to be • Manual or mechanical vibrations to vibrate
plate with multiple openings to generate lost to the ambient air. the thoracic cage
the aerosol. Reported to have better lung • Operator exposure: because of environmental Airway suctioning in comatose or anesthetized
parenchymal penetration contamination, operators may inhale some of animals and/or animals with a tracheostomy:
Drugs that are specifically formulated or the aerosolized drug or saline. A protective • Preoxygenate with 100% oxygen for a
reported to be aerosolized*: face mask can reduce the risk of exposure. minimum of 1 minute before suctioning. Procedures and Techniques
• Antibiotics: aminoglycosides (amikacin, • Low deposition of certain drugs: to allow • The patient should be positioned with the
tobramycin/tobramycin solution for inha- deep penetration to the lower airways, the head raised at a 45° angle and the catheter
lation [TSI], and gentamicin), polymyxins majority of the droplets produced should inserted into the endotracheal/tracheostomy
(colistin or polymyxin E), and vancomycin be within the range of 1-5 micrometers. tube.
• Airway humidification: sterile 0.9% saline Nebulizer type, use of nonaerosolized drug • Suction should begin while the catheter is
• Antifungals: amphotericin B formulations, and highly viscous solutions gradually withdrawn from the airway. Do not
• Bronchodilators: racemic epinephrine, beta-2 are causes of poor drug penetration. suction for more than 15 seconds without
agonist (e.g., terbutaline, albuterol) • Iatrogenic infection: contamination of the reoxygenation. Oropharyngeal secretions
• Antiinflammatory: glucocorticoids, lidocaine nebulizer or drugs can effectively deliver should be suctioned after tracheal suctioning.
• Mucolytic drugs: N-acetylcysteine potential pathogens into the deep airways
• Oxygen free-radical scavengers: heparin/N- of an already compromised patient. Postprocedure
acetylcysteine combination Airway suctioning: • Monitor closely for desaturation and hypox-
• Suctioning may cause tracheal irritation and emia after the application/administration of
Anticipated Time bleeding, abrupt drop in partial pressure of any of the above therapies.
• Nebulization: 15-30 minutes to allow suf- oxygen, vagal stimulation, and bradycardia. • Decompensation may occur as a result of
ficient time for adequate drug delivery/effect. Preoxygenating and limiting suction time bronchoconstriction, incomplete mobiliza-
Longer times are generally not tolerated by have been shown to reduce the risk of tion of mucus causing airway obstruction,
the patient or the operator (poor compli- hypoxemia. tracheal irritation, or exhaustion.
ance). Nebulization and coupage should be
performed every 6-12 hours. Procedure Alternatives and Their
• Chest physical therapy, ambulation, percussion/ Nebulization and coupage: Relative Merits
vibration, and airway suctioning should • Follow manufacturer’s instructions carefully Metered-dose inhaler (MDI; p. 1122) is a more
be performed every 2-4 hours initially and to ensure proper use. In general, sterile 0.9% practical alternative for at-home delivery of
gradually tapered as secretions improve. saline or the specific drug diluted with sterile specific medications. However, only certain
0.9% saline is instilled in the nebulizer medications are routinely available in MDI
Preparation: Important reservoir. With the nebulizer on, place the form.
Checkpoints reservoir approximately 2-3 inches (5-8 cm)
• Keep equipment for nebulization and airway from the patient’s nose for 15-30 minutes. SUGGESTED READING
suction sterile. Gloves (sterile or clean) should Face masks or tents can facilitate nebuliza- Chow KE, et al: Scintigraphic assessment of deposi-
be worn when manipulating equipment. tion. Certain nebulizers can be attached to tion of radiolabeled fluticasone delivered from a
Nebulization reservoirs should be replaced the inspiratory limb of a ventilation circuit, nebulizer and metered dose inhaler in 10 healthy
or cleaned daily and a new suction tip used facilitating nebulization in mechanically dogs. J Vet Intern Med 31(suppl 31), 2017, https://
for each suction. ventilated patients. doi.org/10.1111/jvim.14832/.
• In-line suction units for mechanically • Perform coupage after nebulization by repeat- AUTHOR: Michael Ethier, DVM, DVSc, DACVECC
ventilated patients can reduce the risk of edly percussing both sides of a patient’s chest EDITORS: Leah A. Cohn, DVM, PhD, DACVIM; Mark S.
iatrogenic infections. wall simultaneously, typically while standing Thompson, DVM, DABVP
• Clean and disinfect equipment between above and behind the patient and using
patients. Disposable parts (e.g., nebuliza- cupped hands and gentle force. Coupage
tion reservoirs) should be exchanged daily for 15-30 seconds or less if coupage triggers
if contaminated and between patients. repeated coughing
Pulmonary (chest) physical therapy:
• In the true sense, this involves 12 basic posi-
*Information for most aerosolized drugs listed are extrapolated
from experimental and human clinical studies, and use in dogs tions for postural drainage. The simplest and
and cats is considered off-label. most practical form for clinical practice is to

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