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1134 Nebulization, Coupage, and Respiratory Therapeutics

Preparation: Important Possible Complications and in the particular case (e.g., obtaining T2*-
Checkpoints Common Errors to Avoid weighted images in suspected hemorrhagic
VetBooks.ir nonferrous metallic implants/foreign bodies? • Burns induced by placement of cables ○ Rarely, the images obtained will identify
lesions).
• Complications associated with general
• Obtain thorough patient history: pacemaker?
anesthesia
an additional area of concern that should
ferrous metallic implants/foreign bodies?
• Routine laboratory evaluation: CBC, serum
hot due to the effect of radiofrequency
biochemistry panel ○ Objects within the magnet can become be scanned before the patient is allowed
to recover from general anesthesia.
• +/− Thoracic radiographs pulses. Monitoring cables within the
• +/− Abdominal radiographs or ultrasound magnet should not be coiled and should Postprocedure
• Many patients undergoing MRI are older not be placed on the patient. Wrapping No additional considerations beyond routine
and may have multiple diseases. Routine the cables in fabric (e.g., towels, blankets) monitoring of the patient during recovery from
laboratory evaluation and thoracic and will provide further protection. general anesthesia
abdominal screening may be indicated in • Injury to the patient and/or damage to the
these patients for two reasons: 1) to rule out magnet can occur if careful attention is not Alternatives and Their
the presence of concurrent disease that may paid to basic safety regarding the presence of Relative Merits
affect the patient’s ability to tolerate general metallic objects within range of the magnet CT:
anesthesia and 2) to identify the presence of (see above). • Advantages
any potentially life-shortening disease process ○ Shorter imaging time (and therefore
unrelated to the primary complaint (e.g., Procedure shorter time under general anesthesia)
incidental splenic mass). • Anesthetize and intubate the patient. ○ Better imaging of bone
• Make sure all needed equipment is available • Move the patient to the MRI area and • Disadvantages
and functional. This is especially important position within the gantry as dictated by ○ Far inferior contrast resolution
if the study is to be performed at an outside the area of interest and the configuration ○ Image acquisition is in only one plane.
(e.g., nonveterinary) facility. of the radiofrequency coils. ○ Reformatted images have much lower
• Preparation for general anesthesia • Connect IV fluids and monitoring devices; spatial resolution than original images
○ Routine preanesthetic fasting place blankets and water bottles. or MR images.
○ Place IV catheter: when placing the cath- • Scan. • If available, MRI is the preferred imaging
eter, the anticipated position of the patient • +/− Inject intravenous contrast agent. method for evaluation of the central nervous
in the MRI unit must be considered, and ○ Contrast is routinely used in brain imaging system.
the catheter should be placed to allow easy and sometimes used for imaging of the
access during the procedure. For example, spinal column. SUGGESTED READING
in patients undergoing a scan of the head, ○ Gd-DTPA (Magnevist) 0.2 mL/kg IV Gavin P, et al: Practical small animal MRI, Ames,
it is convenient to have the IV catheter bolus IA, 2009, Wiley-Blackwell.
placed in the saphenous vein. This is, ○ Gadodiamide (Omniscan) 0.2 mL/kg IV
however, not an absolute requirement bolus AUTHOR: Patricia L. Rose, DVM, MS, DACVR
EDITORS: Leah A. Cohn, DVM, PhD, DACVIM; Mark S.
because the forelimb can be extended • Rescan for postcontrast images. Thompson, DVM, DABVP
caudally for ease of access if the catheter • Briefly review images.
is in a cephalic vein. ○ Evaluation of the images may suggest
○ Clipping of hair in areas where monitoring additional imaging sequences indicated
devices are to be applied (depending on
type of monitoring devices used)

Nebulization, Coupage, and Respiratory Therapeutics

Difficulty Level: ♦♦ positioning to assist mobilization of airway Indications
secretions. Patients with inhalation injury (e.g., smoke inhala-
Synonyms • Early ambulation facilitates mobiliza- tion [p. 919]) or retained secretions (recumbent
• Nebulization: aerosolization tion and clearance of airway secretions, patients, bacterial or fungal pneumonia [p. 795],
• Coupage: thoracic wall percussion changes the lung regions being venti- asthma [p. 84], eosinophilic bronchopneumopa-
• Pulmonary (chest) physical therapy lated, and maintains muscular tone and thy, mechanically ventilated or intubated patients)
• Bronchial drainage/positioning strength.
• Thoracic wall percussion/vibration moves Contraindications
Overview and Goals loosened secretions from small airways to • Percussion/vibration usually is not suitable
• Nebulizers are used for aerosolizing saline to larger airways so they can be expectorated in patients with thoracic wall damage (i.e.,
humidify airway secretions or to aerosolize or suctioned. fractured ribs or recent thoracotomy).
drugs to obtain high local concentrations while • Airway suction is the active removal of airway • Nebulized antibiotics are recommended in
minimizing systemic absorption and toxicosis. secretions in patients with impaired mucocili- humans only for multidrug-resistant, gram-
• Coupage aids in the removal of secretions ary clearance. It reduces the risk of lower negative infections that are susceptible to
from the tracheobronchial tree. airway contamination from oropharyngeal aminoglycosides or polymyxin E (colistin);
• Pulmonary (chest) physical therapy or bron- contamination or atelectasis from mucus gram-positive bacterial infections are relative
chial drainage/positioning uses gravity-assisted plugs. contraindications.

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