Cough 2 Flashcards
Which one (IAD or RAO) have the following characteristics:
- Occasional cough
- -Poor performance
- No increase RR
IAD (Inflammatory Airway Dz)
Which one (IAD or RAO) have the following characteristics:
- Regular to frequency cough
- exercise intolerance
- increased respiratory effort
RAO
What age group is affected by IAD & RAO
- IAD =
- RAO=
Age groups
IAD= young -middle aged (any age)
RADO = >7 yo
Which disease can be controlled but NOT cured (IAD or RAO)
RAO
– last for weeks, improve with strict environmental control or tx
Which disease often improves spontaneously or with minor tx (IAD or RAO)
IAD
Which disease is often seasonal (pollens or allergens)
RAO
– IAD is not seasonal = can seem seasonal if the horse only races once a year
Which disease is associated with the following (IAD or RAO)
- Airway hyper-responsiveness
- Ariway obstruction
- Airway remodeling
Both RAO and IAD:
- Airway hyper-responsiveness
- Airway obstruction
- Airway remodeling
What did RAO used to be referred to:
COPD
- no longer called COPD
- Preferred name is RAO or “Heaves”
T/F: both IAD and RAO are considered equine asthma
True
– both IAD and RAO represent a spectrum of chronic inflammatory dz of airway.
Term to describe mild (IAD) to severe (RAO) airway disease
Equine Asthma
- IAD does not necessarily develop to RAO over time
- -No evidence of mild case (IAD) will increase the risk of developing RAO
IAD is most noticeable in what type of horses
Athletic horses
- -IAD most noticeable in athletic horses
- -Main contributor is the high levels of particulates in the environment (viral, bacterial, or genetic predisposition).
The main contributor to IAD is the high levels of:
High levels of particulates in the environment – Viral / Bacteria/ Genetic predisposition.
For IAD, elevated _____ cells in BAL suggest a degree of allergic response
Mast cells
– no evidence of IgE involvement in IAD
If all other test seem normal but the horse still has poor performance then consider what disease
IAD
– run BAL to see mast cells
Diagnostic of choice for IAD
BAL – to see mast cells
or pulmonary function test
T/F: For IAD, You want to have surfactant in the BAL sample bc I will make a buffer coat of white foamy bubbles which proves you are deep all the way to the alveoli
True
- -Neutrophils >10%
- Mast cells >5%
- -Eosinophils >5%
What is the test that evaluates if the animal has adequate airflow
Pulmonary function test
- Oscillometry or plethysmography
- determents: Pressure, Volume and flow
What test quantifies the hyperresponsiveness of the airway
Histamine Bronchoprovocation
- Get baseline first
- take histamine and nebulize the horse causing bronchoconstriction
- this quantifies the hyperresponsiveness of the airway by increasing the amount to see how reactive they are.
Common condition in mature horses of the Northern hemisphere
RAO
What is the inflammatory condition of the lower respiratory tract that is caused by an environmental source
RAO
Which disease (IAD or RAO) is associated with excessive mucus production & reversible bronchospasm (bronchoconstriction)
RAO characterized by:
- Excessive mucus production
- Neutrophil accumulation
- Bronchial hyperreactivity
- Reversible bronchospasm (bronchoconstriction)
What type is RAO associated with:
Wet and cool climate = RAO
– rarely occurs in warm dry areas
RAO usually occurs during poor ventilation (dusty, moldy hay (round bales), dust, pollen and mold exposure). When does exposure occur:
Exposure occurring 1 to 3 months previously
Key to diagnosis of ROA:
Nostril flaring and a markedly accentuated EXPIRATORY effort (heave)
other signs:
- Nasal Discharge may not be evident
- -Tachypnea (resp rate exceed 40 breaths/min)
What disease is associated with the following clinical signs:
- Anxious facial expression
- reluctance to move
- inappetence & wt loss occur in severely affected horses
- -HEAVE LINES
ROA
The main complaint from owners with a ROA horse
– abnormal breathing effort
What can be used during physical exam to hear abnormal lung sounds in a ROA case
Rebreathing bag
– in mildly affected horses, crackles or high pitched expiratory wheezes may be detected.
Exposure to moldy hay, endotoxins or fungal spores result in:
Airway Neutrophilia
- inflammation
- bronchoconstriction
- -mucus accumulation
- -airway thickening
- -gas exchange impaired
Inflammation in ROA causes epithelial cell destruction resulting in:
Delayed clearance of the mucus
– controversy of TH1 and TH2 inflammatory rxn
What is the result of peribronchial infiltrate and epithelial metaplasia
Airway thickening
- goblet cells will be growing and be hyperplastic and secreting more mucus.
- the contraction of smooth muscle in the airways
- -Bronchoconstriction is reversible bc no fibrous tissue
In bronchoconstriction, what are the inflammatory mediators that are released
Histamine
Serotonin
Eicosanoids
Leukotrienes
Which inflammatory mediators are responsible augmenting the released of acetycholine from parasympathetic nerves
Histamine & Serotonin augment the release of acetycholine from parasympathetic nerves.
– Acetycholine activates muscarinic receptors on smooth muscle resulting in bronchoconstriction
What activates muscarinic receptors on smooth muscle resulting in bronchoconstriction
Acetycholine
Histologic ROA changes are:
Histologic Histologic changes:
- Goblet cell hyperplasia
- Epithelial cell damage
- Bronchial & bronchiolar epithelial cell hyperplasia
- Smooth muscle hypertrophy & hyperplasia
- Collagen deposition
- Overinflation of the alveoli
T/F: Both IAD & RAO need hematology to rule out other conditions
True
What type of inflammation is viewed on cytological analysis of ROA
Suppurative nonseptic inflammation
- -Neutrophilia >25% with decrease lymphocyte and alveolar macrophages
- -tracheal mucus accumulation
What is the % neutrophilia associated with IAD & RAO
IAD = >10% ROA= >25%
Which of the following diseases are associated with a HIGH neutrophilia with no affect on eosinophils or mast cells
ROA – >25% with decreased lymphocyte & alveolar macrophages
IAD – >10% Neutrophil, Mast cells >5%, Eosinophils >5%
What is expected to see on a ROA patient on endoscopic examination:
Distal airways are EDEMATOUS and INFLAMED. Airways easily collapse during expiration
– demonstrates tracheobronchial secretions that originate from bronchial segments
What diagnostic test can confirm thoracic effusion
Ultrasound
In diagnosing ROA, what is the hay challenge test
Hay challenge test = horses are exposed to moldy hay which triggers an airway obstruction within hours
Most important aspect in treating RAO:
Environmental management is the most important aspect for treatment
- Well-ventilated stall
- -adequate bedding
- minimized dust
- -pellet feed, hay cubes, soak hay in water
Adjunct therapy for ROA treatment:
Polyunsaturated omega 3 FA combine with low dust diet
3 main classes of bronchodilators:
1.
2.
3.
3 main classes of bronchodilators:
- Anticholinergics (muscarinic antagonist)
- B2 agonist
- Phosphodiesterase (PDE) inhibitors
Name the 2 anticholinergics that block the smooth muscle constricting effects of acetycholine
Atropine & Ipratropium
– Atropines short duration of action (2hours)
Which anticholinergic is used in emergency for quick relief to stabilize the horse
Atropine!
- short duration of action (2 hrs)
- undesirable sides effects: mydriasis, ileus, tachycardia, dry airway secretions
Out of the 2 anticholinergics used, which one has less side effects:
Ipratropium bromide
- onset of action of inhaled ipratropium is 30 minutes and the duration effect ranges from 4-6 hrs.
- powder form may be nebulized
- poorly absorbed by the respiratory or GI tract, minimal systemic effects.
What are the beta 2 adrenergic agonists used to relax smooth muscle by increasing the intracellular levels of cAMP: 1. 2. 3. 4. 5.
Beta 2 adrenergic agonists- relax smooth muscle
- Clenbuterol
- Albuterol
- Fenoterol
- Pirbuterol
- Salmeterol
Which beta 2 adrenergic agonist can be used as a nebulizer drug:
Albuterol
T/F: If the horse is on Clenbuterol and no clinical improvement is not observed within 3 days, the horse should be taken off Clenbuterol.
FALSE
- If clinical improvement is not observed with 3 days, increase dose for another 3 days.
- the effective dose of clenbuterol may vary among horses.
T/F: Clenbuterol relaxes smooth muscle and exerts an anti-inflammatory effect
True
Anxiety, shivering, sweating, and tachycardia are all adverse side effects of CLenbuterol. How can this be avoided?
Adverse side effects are minimized when Clenbuterol is increased in a stepwise manner.
What is the MOA of phosphodiesterase inhibitors:
–PDE inhibit the breakdown of intracellulae cAMP, maintaining smooth muscle relaxation.
Name 2 phosphodiesterase Inhibitors:
Aminophylline
Pentoxifylline
– well absorbed PO
T/F: Phosphodiesterase inhibitors have similar effects of atropine while lacking adverse side effects.
True
– PDE have bronchodilator effect but not enough to save the horse (ADJUNCT THERAPY)
T/F: Oral prednisone is the best treatment for a horse with ROA
FALSE!!!!!!!! ==> On exam
– Oral prenisone is therapeutic failure bc it is NOT metabolized in horses.
Why is oral prednisone a therapeutic failure:
Prednisone has poor absorption and the lack of conversion to the active metabolite PREDNISOLONE *****
What medicine is used to cure an ROA horse
CORTICOSTEROIDS
- Dexamethasone
- Prednisolone
Which corticosteroid produces a significant improvement in lung function parameters within 6 hours of treatment, with peak effects occurring 24 hours later.
Dexamethasone oral
–other corticosteroids: triamcinolone acetonide & Isoflupredone
Is it best to administer the glucocorticoid or bronchodilator first?
Bronchodilator FIRST – improves glucocorticoid deposition
What is used for maximal therapeutic effects for ROA treatment
inhaled steroids in conjunction with inhaled bronchodilators
–Ex. steroids + albuterol = great combo for foals
T/F: In metered dose inhalers, the inhaler system needs a spacer to optimize the drug particle size to be deposited in the lower respiratory tract.
True
