Exam 2 - Airway Disorders Flashcards
what is the general pathogenesis of the collapse of the trachea & mainstem bronchi?
cartilage rings lose rigidity & reduction of glycosaminoglycans & chondroitin sulfate in cartilage rings
what is tracheomalacia?
collapse of the trachea
what is tracheobronchomalacia?
collapse of the trachea & bronchi
what is bronchomalacia?
collapse of the bronchi supported by cartilage
45-83% of dogs with tracheal collapse also have what other condition?
bronchomalacia
what animals are typically affected by tracheal collapse?
middle-aged toy & small breed dogs
what clinical signs are seen with tracheal collapse?
often episodic & progressive in nature
honking cough, stertor if extrathoracic trachea, respiratory distress, & trachea sensitivity on palpation
coughing leads to ______ which leads to ______ creating a vicious cycle
airway collapse
inflammation & edema
how is a collapsing trachea diagnosed?
inspiratory & expiratory radiographs, fluoroscopy to assess for dynamic collapse, & tracheoscopy (more invasive)
what is considered the gold standard for diagnosing a collapsing trachea?
tracheoscopy
how does the trachea fluoresce on fluoroscopy?
white
what should you set up for owner expectations in patients with tracheal collapse?
irreversible, goal is to manage clinical signs, often is progressive, & their pet will still have flare ups
what medical management of the environment can be used for dogs with tracheal collapse?
harness instead of neck leash, optimum body weight, avoid heat stress/intense exercise/excitement
what medical therapy can be used for dogs with tracheal collapse?
sedatives, cough suppressants
why use cough suppressants in a dog with a collapsing trachea? how should you dose them?
goal is to break the cough cycle & improve the quality of life
frequent dosing for a few days, gradually increase interval between doses
sedation is the most common side effect
why would you use prednisone for a patient with tracheal collapse? how would you dose it?
control tracheal or bronchial inflammation - 1mg/kg/day for 1 week & taper them off
T/F: bronchodilators have no effect on larger airways & therefore, won’t be useful in an animal with a collapsing trachea
true
what is the emergency management used for a patient with a collapsing trachea?
oxygen supplementation, sedatives, & keep the animal cool
what is the purpose of surgery for tracheal collapse?
last resort - palliative option used after medical management fails
used to establish a patent airway - but won’t treat the collapsing mainstem bronchi
what is very important in using surgery for a patient with a collapsing trachea?
will need to control the cough first & the animal will still require medical management after the procedure
what are some examples of potential complications associated with tracheal stenting?
tracheal perforation, stent migration or fracture, & stent collapse
what are some examples of potential complications associated with extraluminal rings?
laryngeal paralysis, tracheal necrosis, pneumothorax, & collapse of adjacent airways
what are the components of feline asthma?
common, allergic lower airway disease that causes airway inflammation
why does bronchospasm occur in feline asthma?
hyper-responsiveness & restricted airflow
what happens with chronic inflammation in feline asthma?
airway remodeling
what is the median age of cats affected by feline asthma?
4-5 years
what are the clinical signs of feline asthma?
episodic, may be chronic, cough, tachypnea, & increased respiratory effort on expiration or expiration & inspiration
if a cat presents during an asthmatic episode, what may you see clinically?
tachypnea, dyspnea, open-mouth breathing, & sometimes increased expiratory effort
why can it be hard to diagnose feline asthma?
animal may present between episodes - have the owner record the cat
T/F: feline asthma is often a presumptive diagnosis
true
what may be seen on radiographs from a cat with asthma?
bronchial/bronchointerstitial pattern
collapse of the right lung lobe from mucus trapping
hyperlucent (hyperinflated lungs)
flattening of the diaphragm
why is airway wash not typically done in cats with suspected asthma?
scoping or wash can induce bronchospasm
what additional testing should be run in a cat with suspected asthma?
heartworm testing, r/o lung worms, & CBC to look for eosinophilia
what is the emergency management done for cats with feline asthma?
oxygen, consider sedation, bronchodilator (terbutaline IM/IV, albuterol inhaler), & dexamethasone IM/IV
what is the chronic management done for cats with feline asthma?
corticosteroids - to reduce inflammation & mucus production
avoid methylprednisolone
start with oral pred
add inhaled fluticasone
wean pred over 2-3 weeks
how is inhaled corticosteroid therapy used for feline asthma?
shake inhaler & insert into chamber - apply mask over nose & mouth
7-10 breaths
why are bronchodilators used for rescue only in asthmatic cats?
they have pro-inflammatory effects which can result in permanent airway damage
what is feline chronic bronchitis?
chronic airway inflammation without bronchospasm
feline chronic bronchitis is clinically indistinguishable from what other disease in cats?
feline asthma
how is feline chronic bronchitis diagnosed?
airway wash characterized by non-degenerate neutrophils
what are some differentials for a bronchial pattern on thoracic rads of a dog?
chronic bronchitis, allergic bronchitis, bacterial infection/kennel cough, & pulmonary parasites
what cytology is seen with canine chronic bronchitis?
mild, predominantly neutrophilic inflammation
T/F: bronchoconstriction is the hallmark of canine chronic bronchitis
false - it is absent
what is characteristic of canine chronic bronchitis?
chronic neutrophilic inflammation
what dogs are commonly affected by canine chronic bronchitis?
often older adult dogs
what are components of disease seen in canine chronic bronchitis?
bronchial wall thickening, excessive mucus production, unknown cause
what is the common clinical presentation of a dog with canine chronic bronchitis?
cough > 2 months duration of variable severity, exercise intolerance, may have increased lung sounds or crackles
what are the main components of managing canine chronic bronchitis?
chronic management, controlling clinical signs, reducing inflammation, & slow airway remodeling
what are some general changes made for managing canine chronic bronchitis?
maintaining a healthy weight, limit activity/excessive barking, & eliminate potential environmental irritants
what should be avoided in the environment for an animal with canine chronic bronchitis?
cigarette smoke, wood smoke, wall to wall carpet, scented cleaning products, scented candles, room sprays, essential oil diffusers
what medications can be used for management of canine chronic bronchitis?
glucocorticoids - pred & taper by 25% in 2-3 week intervals & maintain at the lowest effective dose
cough suppressants - once inflammation is controlled, if the cough is non-productive, & help dog sleep at night
what airway changes may be seen in canine chronic bronchitis?
fibrosis, bronchiectasis, pulmonary hypertension, irreversible bronchial dilation, destruction of the walls, & predisposes the animal to recurrent bacterial infections
T/F: there is a cure for canine chronic bronchitis
false
if there are acute worsening signs in your patient with managed canine chronic bronchitis, what should you consider?
secondary infection - radiographs, airway wash, & empirical antibiotic therapy
possibility of new etiology - airway collapse, valvular disease, neoplasia
consider short course of pred & then taper
what is canine chronic bronchitis?
bronchitis in dogs that is characterized by neutrophilic inflammation, can be a hypersensitivity reaction, may be acute or chronic, & disease can only be managed not cured
