Respiratory Flashcards
Cranial nerve whose branches innervate the intrinsic muscles of the canine larynx. Also name of the branch
Vagus nerve (10th pair), recurrent laryngeal nerve branches
Muscles that contribute to the abduction of the arytenoid cartilages
Intrinsic laryngeal abductor and cricoarytenoideus dorsalis
Breeds affected by congenital laryngeal paralysis
Bouvier de Flandres, bull terriers, Siberian huskies and white coated German Shepherd
Proposed etiologies of laryngeal paralysis (7)
Congenital (Bouvier the Flanders Road, bullterriers, Siberian huskies, white coated German shepherds)
Accidental trauma (Penetrating wounds)
Surgical trauma (cranial thoracic surgery, thyroidectomy, parathyroidectomy, tracheal surgery, ventral slot)
Cervical or intrathoracic
neoplasia (Lymphoma, thyroid carcinoma)
Neuromuscular disease (Geriatric onset, hypothyroidism, hypoadrenocorticism)
Immune mediated (Myasthenia gravis, polymyopathy, infectious)
Systemic lupus erythematosus
Describe the basic goal of the most common method of surgical treatment of laryngeal paralysis
The most common technique involves suturing the cricoid cartilage to the muscular process of the arytenoid cartilage. This mimics the directional pull of the cricoarytenoid dorsalis muscle and rotates the arytenoid cartilage laterally.
Describe the Arytenoid lateralization technique
Make a skin incision just ventral to the jugular vein, beginning at the caudal angle of the mandible and extending over the dorsolateral aspect of the larynx to 1 to 2 cm caudal to the larynx (Fig. 28.28A). Incise and retract the SC tissues, platysma, and parotidoauricularis muscles. Retract the sternocephalicus muscle and the jugular vein dorsally and the sternohyoid muscle ventrally to expose the laryngeal area. Palpate the dorsal margin of the thyroid cartilage. Incise the thyropharyngeus muscle along the dorsolateral margin of the thyroid cartilage laminate Place a stay suture through the thyroid cartilage lamina to retract and rotate the larynx laterally. Identify and transect the cricoarytenoideus dorsalis muscle. Disarticulate the cricothyroid articulation with a No. 11 blade or scissors (Fig. 28.28B); however, this step is often unnecessary. Palpate, identify, and disarticulate the cricoarytenoid articulation at the muscular process. Place a nonabsorbable monofilament suture (e.g., 2-0 to 0 polypropylene [Prolene], polybutester [Novafil]) from the caudal one-third of the cricoid cartilage near the dorsal midline to the muscular process of the arytenoid cartilage to mimic the direction of the cricoarytenoid dorsalis muscle Tie the suture with enough tension to abduct the arytenoid cartilage moderately. Have an assistant verify abduction by intraoral visualization of the larynx. If abduction is insufficient, the suture can be repositioned to achieve better abduction. Lavage the surgical site. Appose the thyropharyngeus muscle in a cruciate or simple continuous pattern with 3-0 absorbable suture. Appose the SC tissues and skin routinely.
Factors associated with an increased risk of aspiration ammonia following arytenoid cartilage lateralization
Increasing age, temporary tracheostomy, progressive neurologic disease, postoperative megaesophagus, ongoing esophageal disease, concomitant neoplasia and postoperative administration of opioids
Name the 12 axial pattern flaps available in dogs.
1) Superficial temporal
2) Caudal Auricular (sternocleidomastoideus branches of the caudal auricular artery)
3) Omocervical
4) Thoracodorsal
5) Lateral thoracic
6) Superficial brachial
7) Cranial superficial epigastric
8) Caudal superficial epigastric
9) Deep Circumflex Iliac
10) Genicular
11) Reverse Saphenous conduit
12) Lateral caudal
What is the use of the superficial temporal axial Pattern flap?
Ipsilateral and contralateral head and face, particularly maxillofacial defects
Which axial pattern flap can be passed through a parapharyngeal tunnel to cover oronasal defects caudal to the third premolar?
Omocervical Axial Pattern Flap
Axial pattern flap utilized to cover defects of the antebrachium
Superficial brachial Axial Pattern flap
Of the 12 Axial pattern flaps available for dogs, how many Have been evaluated in cats? What are their names?
6
Superficial temporal, Caudal auricular, superficial cervical, thoracodorsal, caudal superficial epigastric, reverse saphenous conduit flap
Describe the grading system utilized for Tracheal Collapse
Grade 1 -Normal tracheal anatomy; Redundant dorsal tracheal membrane occludes lumen by 25%
Grade 2 – Mild to moderate flattening of tracheal cartilages; 50 % loss of luminal diameter
Grade 3 – Severe flattening of tracheal cartilages; 75% loss of luminal diameter
Grade 4 – Complete obstruction; tracheal lumen is obliterated
The overall complication rate for extratracheal Vs endotracheal surgical options for treatment of tracheal collapse
The overall complication rate for extratracheal Vs endotracheal methods is similar, around 42% to 43%
Complications associated with endotracheal stent placement for treatment of tracheal collapse
Endotracheal prosthesis may be incorrectly placed or sized, leading to death. Too small implants may migrate, while too large implants may lead to tracheal necrosis. Stents too close to the larynx may lead to intractable laryngospasm. Granulomas may develop in 20 to 30% of cases and require management with steroids. Persistent cough, pneumothorax, emphysema, infection, mucous obstruction, tracheal rupture, ulceration of the tracheal epithelium, implant fracture, implant collapse or deformation.
Complications associated with the placement of extra tracheal rings for treatment of tracheal collapse.
Extratracheal prosthetic ring application may lead to damage to tracheal vasculature and innervation (Recurrent laryngeal nerves) during application, leading to tracheal necrosis and laryngeal paresis/paralysis respectively. Infection deriving from penetration of the tracheal lumen; Improperly aerated EO sterilized prosthesis (syringe case rings) can lead to extensive tissue reaction; These complications may be lethal.
Spinal segment origin of the phrenic nerves
C5,6 and 7
Respiratory infections are often caused by gram negative bacteria. What antibiotics are typically used to treat these infections?
“Antibiotics commonly recommended for treatment of upper respiratory disease include ampicillin, fluoroquinolones, cephalosporins, doxycycline, azithromycin, and potentiated sulfonamides (see Box 28.4).”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
What bacteria are most commonly isolated from the respiratory tract of normal dogs?
“Streptococci, Escherichia coli, Pseudomonas spp., Klebsiella spp., and Bordetella bronchiseptica are the bacteria most commonly isolated from normal dogs.”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
How much of the trachea can be resected and still directly anastomosed?
“Depending on the degree of tracheal elasticity and tension, approximately 20% to 50% of the trachea in an adult dog (approximately 8–10 rings) may be resected and direct anastomosis achieved”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
When is ventriculocordectomy considered acceptable according. To AVMA? What’s the preferred approach?
“The policy of the American Veterinary Medical Association regarding canine devocalization is that it should only be performed by qualified, licensed veterinarians as a final alternative to euthanasia after behavioral modification to correct excessive vocalization has failed and after discussion of potential complications from the procedure with the owner. Ventriculocordectomy may be performed through an oral or ventral (laryngotomy) approach. The ventral approach is recommended.”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
Discuss the healing mechanism of the trachea
“Tracheal epithelium responds immediately to irritation or disease by increased production of mucus. If the insult continues, cells desquamate and goblet cell hyperplasia occurs to increase the protective mucous layer. Superficial wounds heal by reepithelialization. Healing begins within 2 hours after sloughing of superficial cells. Intact ciliated columnar cells surrounding the defect flatten, lose their cilia, and migrate over the wound. Mitosis begins approximately 48 hours after injury in the ciliated columnar and basal epithelial cells. Organization and differentiation begin after 4 days. Squamous cells replace ciliated and goblet cells if injury recurs without healing. Full-thickness tracheal mucosal wounds with a gap between mucosal edges fill with granulation tissue before reepithelialization. Full-thickness wounds may heal with scar tissue protruding into the lumen. Scar tissue narrows the lumen and may interfere with transport of mucus. A 20% reduction in lumen diameter may reduce mucociliary clearance by more than 50%.”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
Five most common errors in managing patients with upper respiratory disease
“• Failing to diagnose and treat upper respiratory disease before secondary problems develop (i.e., aspiration pneumonia)
• Failing to recognize laryngeal collapse
• Causing trauma to the recurrent laryngeal nerves
• Rough handling or overhandling of tissue, causing excessive swelling
• Failing to monitor the patient intensively after surgery”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
What brachycephalic breed is most likely to have a poor outcome from upper airway surgery?
“English bulldogs are more likely to have a negative outcome compared with other breeds.11”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.