E2: Respiratory sounds: Cough, Stridor, RAO, IAD Flashcards by Lorelei Pentifallo

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)

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High intensity exercise results in decreased peripheral blood _______ function.

Neutophil

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In a normal horse, which muscle/nerve (left/right) takes longer to respond when performing an electrolaryngeography?

Left

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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)

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How long (approximately) does it take airway epithelium to heal?

About 7 weeks

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What are the 2 protective mechanisms that function together in the airways?

Mucocilary escalator

Cough reflex

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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

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_____________ is a constant compenent of cough.

Bronchoconstriction

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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

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What is the most common secondary organism that can cause coughing in horses?

Aspergillus

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What cells produce the surfactant-like substance which aids in maintaining patency of the airway?

Clara cells

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Which equine respiratory virus which causes coughing in horses, causes human meningitis?

Hendra virus

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Which virus that causes coughing is common in foals with SCID?

Equine adenovirus

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Which virus that causes coughing, has no age prediliction, and is usually subclinical, results in a long lasting immunity?

Equine viral arteritis

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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)

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Which of these causes stridor without distress ONLY at inspiration? (Also, what do these stand for?)

DDSP

RLN

RLN (Recurrent Laryngeal Neuropathy)

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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.

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What’s going on here?

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How do ‘horse people’ descirbe the gurgling, rattling, snoring, fluttering noise associated with DDSP?

Choking down

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What is the preferred surgery to correct DDSP?

Laryngeal tie-forward

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T/F: Coughing indicates LRD.

False, lower or upper

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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

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Which disorder causes of stridor due to obstruction occuring at high speed?

Epiglottic entrapment (EE)

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Dysfunction of which nerve (specifically) and which muscle have been associated with DDSP?

Pharyngeal branch of Vagus nerve

Thyrohyoideus muscle

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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?

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?

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) ## Footnote _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)*