E2: Respiratory sounds: Cough, Stridor, RAO, IAD Flashcards
What are the 4 most common causes of aspiration in horses?
Stomach tube misplacement
Choke
Laryngeal hemiplasia
Dysphagia (Neonatal encephalopathy, Botulism, Guttural pouch disease, Strangles)
High intensity exercise results in decreased peripheral blood _______ function.
Neutophil
In a normal horse, which muscle/nerve (left/right) takes longer to respond when performing an electrolaryngeography?
Left
What is the first line intervention if you have a horse with an upper respiratory tract dysfunction resulting in dyspnea? What if the problem is in the lower respiratory tract?
Upper: Tracheostomy
Lower: Oxygen supplementation
(When in doubt, do tracheostomy and put O2 tube down trach-hole)
How long (approximately) does it take airway epithelium to heal?
About 7 weeks
What are the 2 protective mechanisms that function together in the airways?
Mucocilary escalator
Cough reflex
Which of these are anaerobic bacteria that can result infections involving coughing?
- Stretococcus zooepidemicus*
- Actinobacillus equuli*
- Bacteroides fragilis*
- Pseudomonas*
- Rhodococcus equi*
- Escherichia coli*
Bacteroides fragilis
_____________ is a constant compenent of cough.
Bronchoconstriction
Which virus is a major cause of respiratory disease and coughing in horses, usually affects younger (3 year old) horses, is associated with crowding and stress, and causes the destruction of the ciliated epithelium?
Equine influenza
What is the most common secondary organism that can cause coughing in horses?
Aspergillus
What cells produce the surfactant-like substance which aids in maintaining patency of the airway?
Clara cells
Which equine respiratory virus which causes coughing in horses, causes human meningitis?
Hendra virus
Which virus that causes coughing is common in foals with SCID?
Equine adenovirus
Which virus that causes coughing, has no age prediliction, and is usually subclinical, results in a long lasting immunity?
Equine viral arteritis
What causes decreased ability for oxygen to be released at the tissue site leading to hypoxia following smoke inhalation?
Carboxyhemoglobin
(Note: Diagnosed if >10% in blood)
Which of these causes stridor without distress ONLY at inspiration? (Also, what do these stand for?)
DDSP
RLN
EE
RLN (Recurrent Laryngeal Neuropathy)
What’s going on here?
DDSP
Cannot visulaize epiglottis in nasopharynx
Expiratory disturvance occurs because caudal border of soft palate billows and vibrates throughout expiration.
What’s going on here?
EE
How do ‘horse people’ descirbe the gurgling, rattling, snoring, fluttering noise associated with DDSP?
Choking down
What is the preferred surgery to correct DDSP?
Laryngeal tie-forward
T/F: Coughing indicates LRD.
False, lower or upper
If you have a dyspnic horse patient that is panicking and thus too dangerous for you to treat, what do you do?
Have everything for the procedure set up and let the horse collapse, then work fast
Which disorder causes of stridor due to obstruction occuring at high speed?
Epiglottic entrapment (EE)
Dysfunction of which nerve (specifically) and which muscle have been associated with DDSP?
Pharyngeal branch of Vagus nerve
Thyrohyoideus muscle
What part of the larynx is paralized/weakened and axially displaced in the face of high negative inspiratory pressure in a horse with LH?
Arytenoids
Is EE typically persistent or intermittent?
Persistent
Are most cases of DDSP persistent or intermittent?
Intermittent
What’s going on here?
EE
You run a CBC on a couhging patient you suspect has pneumonia. The results show neutrophilia and anemia. What do these results indicate?
Chronic infection/disease
Match these pathological issues with the corresponding lung sounds:
Pneumonia
Pleuropneumonia
Pleural Effusion
Sounds:
Ventral dull sound
Increased lung sounds, crackles, wheezes
Cardiac sound larger area than normal
Pneumonia: Increased lung sounds, crackles, wheezes
Pleuropneumonia: Ventral dull sound
Pleural effusion: Cardiac sound larger area than normal (due to improved sound conduction)
What tissues “entrap” the epiglottis in EE?
Aryepiglottic and subepiglottic tissues
What is the typical signalment for a horse with LH?
2-3 year old large, long necked racehorse
What is likely if you choose conservative treatment for EE?
Recurrence
Which pathology is difficult to diagnoe but often assocaited with DDSP and EE?
Hypoplasitc epiglottis
What is typically the cause of persistent DDSP?
Neurologic dysfunction/disease
What is the “horse people” term for speed slowed dramatically during a race, especially during the last half of the race, associated for DDSP?
Quitting
Which of the following causes of coughing are usually associated with fever?
RAO
Parasites
EHV
EIPH
Trauma
Equine influenza
Foreign body
Trauma
Neoplasia
Equine herpes
EHV
Equine influenza
Equine herpes
Which surgical method is preferred to correct EE?
Transendoscopic laser correction (Nd:TYAG laser)
What does it indicate if you notice small ulceration on the caudal free border of the soft palate endoscopically while evaluating a horse for DDSP?
Chronicity - occurs secondary to repeated treama of dislocation esp. when coughing
What can you use to treat RAO?
Corticosteroids
Antibiotics
Bronchodilators
What nerve is most related to the cough neural pathway?
Vagus nerve
What iatrogenic cause for LH is thought to be common potential cause?
Perivascular jugular injections
You run a CBC on a couhging patient you suspect has pneumonia. The results show hyperfibrinogenemia and neutropenia. What do these results indicate?
Acute disease
What cause of stridor can be the result of guttural pouch disease?
LH
What side is affected in ILH (idiopathic LH)?
Left
What are you differentials for upper airway obstruction?
Strangles
Bilateral laryngeal hemiplasia/paralysis
Arytenoids chondirits
Acute viral respiratory disease
(Less likely: Guttrural pouch tympany, LSA)
Describe the stidor heard with LH.
Inspiratory roar/whistle that gets worse the longer and harder the horse works
What drugs used to treat RAO block the smooth muscle constricting effects of acetylcholine? What are the side effects?
Atropine, Ipratropium (Anti-cholinergics)
Side effects: mydriasis, ileus, tachycardia, dry airway secretions
In bilateral cases of LH, consider the possibility of generalized severe inflammation of upper airway, bilateral guttural pouch disease, and neurologic disoders such as ____ toxicosis, equine protoxoal myelitis, oxidatize damage, etc.
Lead
What is the diagnostic test for LH called that involved slapping the saddle area of the thorax resulting in an adduction flicker on the contralateral side called? Describe a normal test result.
“Slap” test/ Thoraco-laryngeal reflex
Response in both arytenoids should be symmetric
T/F: Oral prednisone is used to treat RAO in horses.
False, prednISOLONE
For how long does the epiglottis have to remain ventral relative to the soft palate during high speed treadmill endoscopy for a diagnosis of DDSP?
>8 sec
What intermandibular width is undesirable because it may indicate a higher degree of RLN?
< 4 fingers (approx 7cm)
Which respiratory disease is associated with coughing and abortions?
Equine viral arteritits
What aspect of the pathophysiology of RAO results in delayed mucus clearance?
Destruction of epithelial cells
What is/are the preferred surgery /surgeries for LH? At what grades is it indicated?
Tie-back/ Laryngoplasty in combination with ventriculochordectomy
Grade III B and C, Grade IV
What can be combined with a low dust diet to treat RAO?
Polyunsaturated omega-3 fatty acids
Which virus is equine multinodular pulmonary fibrosis associated with? What x-ray pattern is associated with it?
EHV-5 (Herpes)
Diffuse bronchointerstitial patterns with multiple coalescing circular nodules throughout lung field
Which modality is most efficient for evaluating deeper lung parenchyma?
X-Ray
Which functional airway obstruction causes a noise generated by air turbulance in inspiration and expiration, but mostly duirng expiration resulting in cheek puffing?
DDSP
Match the following with either IAD or RAO:
Occasional cough
Regular-Frequent cough
Increased respiratory effort
No increased respiratory effort
>7yo horses
Any age
Improve spontaneously or with minor treatment
Lasts for weeks, improve with strict environmental control or treatment
Seasonal
IAD:
- Occasional cough
- No increased respiratory effort,
- Any age
- Improve spontaneously or with minor treatment
RAO:
- Regular-frequent cough
- Increased respiratory effort
- >7yo horses
- Lasts for weeks, improve with strict environmental control or treatment
- Seasonal
How can IAD be diagnosed?
BAL
Pulmonary function test
You peform a BAL and note nonspectic inflammation as well as >5% mast cells, RAO or IAD?
IAD
What are your differentials for lower airway disease?
RAO
R. equi pneumonia
Acute Viral Respiratory disease
Adult intersitital pneumonia
Severe smoke inhalation
(Less likely: Pneumothorax, ARDS, Diaphragmatic hernia)
Which 2 non-invasive treatments for DDSP are also diagnostic?
Laryngohyoid stabilizer (LSH) TSD or Cornell collar
Tongue-tie
Is bronchospasm associated with RAO or IAD?
RAO
What is the test for LH called where you press on both sides of the larynx to try and elicit a respiratory noise?
Arytenoid depression test
Decreasing environmental challanges, bronchodilators and anti-inflammatories are all indicated to treat RAO. Which one is vital for successful treatment?
Decreasing environmental challanges
Which class of bronchodilators is preferred to treat RAO? Give an example of a drug.
B-2 adrenergic agonists
Albuterol (Dr.DePedro’s fav)
How many tiers does the grade classification system for assesement of equine laryngeal respiratory function in unsedated horses examined at rest have? What if you are assessing a hourse during exercise?
4 (I-IV)
3 (A-C)
T/F: Prednisone is the drug of choice for treating RAO if you can only use one drug.
FALSE
Not predniSONE but predniSOLONE! (or dex)
T/F RAO is best treated with, in addition to environmental control, you administer inhaled steroids in conjuction with inhaled bronchodilators.
True
What presenting complaint would indicate that the best treatment for LH is a ventriculochordectomy?
If the problem is the noise not exercise intolerance
When performing an endoscopic analysis of a horse with RAO or IAD, the distal airways are edematous, inflammed, and easily collapse during _______.
Expiration
What class of drugs used to treat RAO cause relaxation of smooth muscle by increasing the intracellular levels of cAMP? Which one is preferred and by which method of administration? Name another drug that is commonly used.
B2-adrenergic agonists
Albuterol (per prof)
Metered dose inhaler
Also commonly used: Clenbuterol (also has antiinflammatory effects)
Which should be administered first when giving both steroids and bronchodilators via MDI?
Bronchodilators (improve glucocorticoid deposition)
How would you describe the noise made by a horse with EE?
a. Expiratory
b. Inspiratory and Expiratory
c. Inspiratory
d. Inspiratory and mostly expiratory
B. Inspiratory and Expiratory
(In= tissue on epiglottis flutters, Out= air flow over and between the tissue and epiglottis)
What features define a DDSP on endoscopy?
a. Inability to visualize epiglottis
b. Loss of scalloped edge
c. Loss of vasculature of epiglottis
d. Sides of pharynx merging into tissue covering the epiglottis
d. Sides of pharynx merging into tissue covering the epiglottis
(a-c can be both EE or DDSP)
What head positioning is associated with noise caused by DDSP?
Collecting
Holding back
Overcheck
What treatments can you recommend for DDSP?
a. Tie-Back
b. Tongue-tie
c. Sacculectomy
d. Laryngoplasty
e. Tie-forward
f. Cornell collar
b. Tongue-tie
e. Tie-forward (Surgical version of the collar; repositions larynx)
f. Cornell collar (aka LSH, Laryngohyoid stabilizer)
