Respiratory- Exam 2 Flashcards
What is the pulmonary alveolar pressure?
25-30
What is the order of respiratory structures?
Nares- nasal passage - ethmoid- nasopharynx- guttural pouch- larynx- trachea
What is the difference in O2 tension at rest vs. intense exercise?
At rest: 100 mmHg
Exercise: 65-70 mmHg
What allows us to assess lung auscultation based on increasing ventilation
Rebreathing- use a bag over horses head
What makes a horse an obligate nasal breather?
Completely distinct oro/nasopharynx
Horses don’t have a pharynx
How much fluid is held in the guttural pouch?
300 mL
Which is the larger bronchus?
Right mainstem bronchus
What dx test is run if you’re looking for pulmonary dz?
Rads
What dx test is run if you’re looking for thoracic dz?
U/S
When do we use transtracheal wash opposed to bronchoalveolar lavage?
TTW: INFECTIOUS dz of FOCAL origin- can do a sterile culture
BAL: NON-INFECTIOUS DIFFUSE dz
Why can’t you culture a sample obtained from a BAL?
Not sterile and will not get a good evaluation of the culture
What part of the lungs is respiratory tract disease (pneumonia) found?
Cranioventral lung lobes
Where is the transtracheal wash performed?
Junction of middle and distal lower 1/3 of neck, above bifurcation of sternohyoideus m.
What are all the possible dx techniques used to evaluate respiratory dz?
BAL TTW Thoracocentesis Lung aspirate Lung biopsy(rare)
A 2 yr old standardbred gelding presents for a cough and nasal discharge. PE reveals fever, purulent nasal discharge, mild tachypnea, and tachycardia, and normal thoracic auscultation. Which of the following best categorizes the disease in this horse? A. NonWinfectious URT disease B. Infectious LRT disease C. Infectious URT disease D. NonWinfectious LRT disease
C- Infectious URT disease
What in this case indicates it is infectious? A. Tachycardia B. Tachypnea C. Presence of nasal discharge D. The appearance of the nasal discharge E. Age of the horse F. Fever G. Presence of cough
D & F
What in this case indicates it is NOT LRT disease? A. Presence of a cough B. The appearance of the nasal discharge C. Fever D. Presence of nasal discharge E. Tachycardia F. Tachypnea G. Thoracic auscultation
G
Bilateral nasal discharge can be associated to upper or lower respiratory Dz?
A. True
B. False
TRUE
From a uni to a bilateral perspective – the anatomic structure is the end of the nasal septum – rostral to this is uni; caudal is bilateral. UPPER RESP TRACT is ANYTHING in the conducting airway
Cough is associated with upper and lower respiratory Dz?
A. True
B. False
TRUE
BOTH! Think – if you have a scratchy throat, do you cough? YES; also cough with pneumonia. Generic finding – not sensitive for upper or lower
Unilateral nasal discharge is associated with upper and lower respiratory Dz?
A. True
B. False
FALSE
Yes – the separation is at the caudal aspect of the nasal septum ! only components of URT
A horse can manifest a neutrophilic leukocytosis and hyperfibrinogenemia with either URT or LRT Dz?
A. True
B. False
TRUE
Yes – this indicates an infectious inflammatory disease – this is the nature of dz not location!
CASE STUDY: 4WyrWold thoroughbred mare that first presented for mild spontaneous intermittent unilateral epistaxis which first occurred 3 weeks ago – she has developed dysphagia within the last 2 days. No other abnormalities have been noted at this time or previous to the development of this. Categorize disease A. LRT infectious B. LRT non-infectious C. URT infectious D. URT non-infectious
D
you did your classification on appearance of case – it ended up being infectious – BUT – this didn’t look infectious before.
CASE STUDY: 4 yr old thoroughbred mare that first presented for mild spontaneous intermittent unilateral epistaxis which first occurred 3 weeks ago – she has developed dysphagia within the last 2 days. No other abnormalities have been noted at this time or previous to the development of this. What is the likely diagnosis A. Coagulopathy B. Trauma C. Ethmoid hematoma D. Guttural pouch mycosis E. EIPH
D
CASE STUDY: 4 yr old thoroughbred mare that first presented for mild spontaneous intermittent unilateral epistaxis which first occurred 3 weeks ago – she has developed dysphagia within the last 2 days. No other abnormalities have been noted at this time or previous to the development of this. Which of the following is most significant in deciding your Dx? A. Signalment B. Location of epistaxis C. Intermittent nature D. Spontaneous occurrence E. Degree of epistaxis F. Time line G. Presence of dysphagia
G- presence of dysphagia
What is the most common CS in a guttural pouch mycosis (GPM)? A. Laryngeal hemiplegia B. Mucopurulent nasal discharge C. Ozena D. Epistaxis E. Dysphagia
D
Where are the ethmoids and guttural pouches located in reference to the nasal septum?
Ethmoids=rostral
Guttural pouches= caudal
T/F: Both ethmoids and guttural pouches can cause bilateral bleeding
TRUE
Volume of blood determines whether bilateral or unilateral
What is the common signalment for hematomas?
Old, male warmblood
What runs through the medial vs. lateral guttural pouch?
Medial: internal carotid a.
Lateral: maxillary a.
15 yr old Thouroughbred gelding 1 yr history of spontaneous unilateral right nasal
epistaxis. Occasional blood from L. Episodes infrequent. • One month prior to presentation, epistaxis from R
occurred more frequently Q: Categorize the disease
A. LRT infectious
B. LRT nonWinfectious
C. URT infectious
D. URT nonPinfectious
D
15 yr old Thouroughbred gelding 1 yr history of spontaneous unilateral right nasal epistaxis. Occasional blood from L. Episodes infrequent. • One month prior to presentation, epistaxis from R occurred more frequently What is the likely diagnosis? A. Coagulopathy B. Trauma C. Ethmoid hematoma D. Guttural pouch mycosis E. EPIH
C
What is the most significant factor in deciding your Dx? A. Signalment B. Location of epistaxis C. Intermittent nature D. Spontaneous occurrence E. Degree of epistaxis F. Time line
A & F
It took a year – if this was guttural pouch, it is highly unlikely they would be lasting for a year!! There are cases – rare – that show you the timeline of this disease. Past 4W5 months we are more likely NOT having a GPM. Signalment is helpful in focusing you.
Q: What might be the cause of bilateral bleeding in a PEH (Progressive Ethmoid Hematoma) case?
A. Associated coagulopathy
B. Bilateral lesion
C. Large bleeding volume
D. Unilateral lesion invading to opposite side
B, C, D
If you are suspecting respiratory dz but don’t see any specific lesions upon endoscopy- what is the next dx test you will perform?
Rads
T/F: If there is active bleeding at time of scoping- difficult to evaluate
FALSE
You want them to be actively bleeding to better evaluate issue
T/F: You must scope when there is an active bleed to determine the cause, but for GPM you should still see a lesion even with no bleeding
TRUE
What is the #1 cause of bleeding in exercise horse and epistaxis in a horse?
Bleeding in exercise horse: EIPH
Epistaxis: trauma
What are your treatment options for ethmoid hematoma?
Intralesional formalin
Laser ablation
A 10 yr old quarter horse mare is presented for bilateral mild spontaneous intermittent epistaxis. She has an inspiratory and expiratory noise which has developed within the last month despite the problem being present for several months. No other abnormalities have been noted in this horse at any time Q: What is the likely diagnosis? A. Coagulopathy B. Trauma C. Ethmoid hematoma D. Gutteral pouch mycosis E. EIPH
C
What is intralesional formalin?
Create a necrosis and dessicate the lesion
What is laser ablation?
the best technique used to treat ethmoid hematoma
What needs to be done prior to laser ablation surgery and why?
Crossmatch prior and expect the horse needing a transfusion
You are expecting the horse to bleed a significant amount
Most preferred surgical option
What vessels need to be ligated prior to guttural pouch surgery?
Internal carotid artery
External carotid artery
Maxillary artery
What is a complication of guttural pouch mycosis sx?
Blindness
What are the four surgical options for guttural pouch mycosis?
Balloon tipped catheter placement
Detachable self-sealing latex balloon
Transarterial coil placement
Transarterial nitinol intravascular plug
What are the arterial systems of the guttural pouch connected through?
Circle of Willis
T/F: It is essential to close off the retrograde and antegrade aspect of the carotid artery during guttural pouch sx?
TRUE
What is the common age of guttural pouch mycosis patients?
Younger horses
What is the presenting complaint of guttural pouch mycosis?
Mild frank, unilateral epistaxis
What is the #2 CS of guttural pouch mycosis?
Dysphagia
What is the deciding factor of treating guttural pouch mycosis medically vs. surgically?
Medically- no history of epistaxis
Surgically- history of bleeding
What is the typical speed exercise induced pulmonary hemorrhage is seen?
> 14 m/s
What are CS of EIPH?
Epistaxis
Exercise intolerance
None-acute collapse
What is seen in a grade 0-4 EIPH horse?
0: no evidence of hemorrhage
1: flecks of blood/single short stream of blood extending less than a quarter of the tracheal length
2: One continuous stream of blood extending at least 1/2 the length of trachea or multiple streams of blood covering less than one third of tracheal surface
3: Multiple streams of blood covering more than one third of tracheal surface
4: abundant blood in trachea completely covering tracheal surface and pooling at thoracic inlet
What is the typical dx method for EIPH
Endoscope- direct observation of blood in tracheobronchial tree
T/F: Incidence of EIPH is related to duration of exercise and not intensity
FALSE
Related to intensity
What are the three components of the capillary rupture theory for EIPH?
Disruption of pulmonary capillaries as a consequence of high CO required during intense exercise
Stress failure of the vessel wall- tensile strength has been exceeded
Elevated pulmonary vascular system pressures
What are two other theories besides the capillary rupture theory for EIPH?
Lower airway inflammation theory
Concussive lung injury theory
What is the concussive lung injury theory?
Impact or hoof on ground force transmitted as a wave to the scapula –> force transmitted to chest wall –> force travels as a wave through lung to caudodorsal area and then caudal tip of lung results in microscopic shearing
What are some classical CS of EIPH?
Poor performance- “quitting”
Epistaxis- small percent of cases
Coughing
What is the rad pattern of EIPH?
increased interstitial pattern in the caudo-dorsal lung fields
What is a tx commonly given for EIPH?
Furosemide
T/F: Giving furosemide pre-race is most commonly used and recommended?
TRUE
When performing a TTW what cells are you looking for?
Hemosiderophages
What is another tx for EIPH besides lasix?
FLAIR nasal strip
Conjugated estrogens- aminocaproic acid and premarin
Laryngeal hemiplegia will have what kind of noises?
STRIDOR- inspiratory noises