Respiratory Flashcards
T or F:
Bilateral nasal discharge can be associated to upper OR lower respiratory disease.
True.
T or F:
Cough is associated with upper and lower respiratory disease.
True.
T or F:
Unilateral nasal discharge is associated with upper and lower respiratory disease.
False!
*unilateral discharge is usually associated with upper respiratory disease…
—> anatomic location that delineates: CAUDAL edge of the nasal septum*
{Rostral to this: unilateral—>UR;
Caudal to this: bilateral—>LW}
T or F:
A horse can manifest a neutrophilic leukocytosis and hyperfibrinogenemia with either upper OR lower respiratory disease.
True; indicates infectious disease (irrespective of location)
2nd most common clinical sign of guttural pouch mycosis?
Dysphagia!
First most common clinical sign of GPM?
Epistaxis!
What specific structures are usually affected in GPM?
Internal carotid a. (located in the medial pouch);
Maxillary a. (Located in the lateral pouch) *these can be combinations*
If we are suspecting ethmoid hematoma, but cannot confirm on endoscopy, what should we do?
- *Run skull radiographs**;
- Ethmoid hematomas can be in deeper tissue (not accessible by scope)*
How do we medically treat ethmoid hematomas?
Inject with formalin
*can eat into cribiform plate, so if the hematoma has breached, we do NOT want to inject with formalin, because it will go to the brain*
What is the most common cause of epistaxis in the horse?
Trauma!
What’s the classic signalment for an ethmoid hematoma?
Older,
male,
warm-blood (thoroughbred) horses
Why do we think GPM lesions are usually over arteries?
Attracted to oxygen tension…
Why do GPM (or empyema) horses present with dysphagia?
Nerves, most notably the Vagus (with branches, Pharyngeal especially)
… comes off near the middle of the pouch, run at the back of the pouch and run on the floor of the pouch
—> they get a dorsally displaced soft palate
(dysphagia is associated with this resulting dysfunction)
How do we diagnose IAD?
**BAL**…and cytological evaluation revealing:
Neutrophilia >10%;
Mast cells >5%;
And Eosinophils >5% using 250mL saline
What is the pathophysiology behind airway thickening in RAO?
Exposure to particulates —>Peribronchial infiltrates and epithelial metaplasia
How would we diagnose RAO?
Cytological analysis revealing:
suppurative nonseptic inflammation
—> neutrophilia >25%,
…decrease lymphocyte and alveolar macrophages —> tracheal mucus accumulation
How do we treat RAO?
Decrease env’t challenges (need this element for the anti-inflammatories to be effective) Bronchodilator Anti-inflammatories
How can we manage the environment in treating RAO?
Good ventilation in housing,
Adequate bedding,
Minimized dust,
Pellet feed, hay cubes, soak hay in water
What are the 3 main classes of bronchodilators that we should use in treating RAO?
Anticholinergics,
Beta-2 agonists,
Phosphodiesterase inhibitors
How do beta-2 adrenergic agonists relax smooth muscle?
By increasing the intracellular levels of cAMP
If you’re treating a horse with bronchodilator and steroids, which one should be administered first?
Bronchodilator first;
To improve glucocorticoid deposition
What is the normal Pulmonary Arterial Pressure (PAP) at rest vs. during exercise?
at rest (pretty much the same across all species): 25-30 mmHg
exercise: 125 mmHg
What is the bronchial system MABP at rest vs.exercise?
Rest: 100 mmHg
Exercise: 220 mmHg
What is the bronchial system pressure reflective of?
The SYSTEMIC circulation (high-side of system)
How do we begin the physical exam evaluation of respiratory disease?
start with differential airflow:
- evaluate sinuses
- evaluate/palpate larynx and trachea
THEN go into auscultation
Where are we located?
Does this look normal?
Distal nasopharynx
NO because we can’t see the epiglottis;
think dorsally displaced soft palate
Where are we located?
Distal trachea
What is this structure?
Ethmoid turbinate
left side
Which compartment of the guttural pouch do main structures go thru?
(internal carotid a, nerves)
Medial (~200mL)
vs lateral ~100mL
the 2 compartments are separated by the stylohyoid
If we are suspecting infectious, focal disease, what procedure is indicated?
TTW!
If we are suspecting non-infectious, diffuse disease, what procedure is indicated?
BAL!
What is the anatomic location where the distinction is made as to whether the horse will have unilateral vs. bilateral discharge?
Caudal edge of the nasal septum
rostral to the caudal edge of nasal septum?
—> should be UNILATERAL
caudal to the caudal edge of nasal septum?
—> should be BILATERAL
T or F:
A horse can manifest a neutrophilic leukocytosis and hyperfibrinogenemia with either upper or lower respiratory disease.
Trueeee
What is the location of the lesion?
Medial compartment of RIGHT guttural pouch
How is the discharge different in ethmoid hematomas from GPM?
EH: intermittent/purulent
GPM: mucoid type, possible between episodes
Older male horses are more likely to succumb to ______, whereas younger horses are more likely to succumb to ______.
Older male horses: Ethmoid hematoma
younger: GPM
What is the normal respiratory rate for a horse anyhow?
8-20 bpm
*foal: 12-24*
What are 2 terms we use to describe abnormal lung sounds?
-
Crackles: low-pitched, non-musical sounds
- short, explosive sounds -
Wheezes: high-pitched, musical sounds
- long, musical sound associated w narrowing of airways generated by oscillation of bronchial and bronchiolar walls
On pulmonary evaluation via ultrasonography, how would an atalectic lung differ from a consolidated one?
Atalectic: very sharp, concave/convex borders with reduced volume
Consolidated: rounded borders - two convex borders meeting
In progressive ethmoid hematoma, is the epistaxis typically unilateral or bilateral?
Unilateral!
What is the signalment for progressive ethmoid hematoma?
4 yrs +
thoroughbred, warmbloods, Arabians
What would confirm our diagnosis of EIPH on endoscopy?
Direct observation of blood in tracheobronchial tree
What is the reasoning behind treating EIPH with furosemide?
Profound diuresis—>volume reduction—>decreased blood pressure in lung
(*thus diminishing work and pressures)
**
also bronchodilation*
